Method and system for displaying digital art images on a digital art frame with an electronic paper display

Abstract

A system for displaying digital art images includes a server (1) and a digital art frame (2), the digital art frame (2) including an electronic paper display, the digital art frame (2) including mounting means for mounting the digital art frame (2) on a wall, the server (1) configured to store a plurality of dithered digital art images, the number of intensity levels of the processed digital art image is the same as the number of intensity levels of the electronic paper display (21), the number of intensity levels after processing is at least four, and the system configured to transfer one of the processed digital art images to the digital art frame (2) and display the transferred processed digital art image on the electronic paper display (21).

Description

[Technical Field]

[0001] The present invention relates to a method and system for displaying digital art images on a digital art frame with an electronic paper display. [Background technology]

[0002] Digital photo frames and digital art frames are known in the prior art. They are mounted on walls or placed on tables and can display photos selected by users. Most of these digital art frames use emissive displays, such as LCDs and OLEDs, which consume energy while displaying images. This results in significant energy consumption and increases the ecological footprint of such devices. Furthermore, such devices require a fixed power source via a cable, which complicates the installation process and makes them cumbersome for users because they require periodic charging. Therefore, the use of electronic paper displays in digital art frames, such as those described in Patent Documents 1 and 2, has been proposed. Electronic paper displays solve all energy consumption issues by consuming energy only to change the displayed image, not for the display itself. This allows battery-powered digital art frames to be used for extremely long periods of time without charging. However, the best current electronic paper displays can only display 16 gray intensity levels, i.e., 4-bit images. Therefore, photos displayed on digital art frames with electronic paper displays exhibit artifacts and do not meet consumer expectations for digital art frames. This explains why the use of electronic paper displays has been theoretically considered, but has never been used in practice except in some limited cases for less complex documents, such as that described in Patent Document 1 for displaying certificates.

[0003] Other applications of electronic paper displays involve dithering the images they display. In Patent Document 3, dithering is performed on the electronic display device itself. Server-based dithering as a preprocessing step for images displayed on an electronic paper display is known for video. Patent Document 4 discloses displaying video images on an e-reader in 1-bit mode. The 1-bit mode increases the display speed of video images, allowing e-books to process the video. However, the 1-bit mode only displays black and white. To compensate for the quality loss caused by the 1-bit mode, the video image is dithered before being sent to the e-reader. Patent Document 5 discloses dithering images to prevent ghosting, i.e., shadows of previous images. Therefore, in the current state of the art for electronic paper displays, server-based dithering is primarily used for black and white or 1-bit images for displaying video on an e-paper display. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 9443368 [Patent Document 2] Taiwan Utility Model No. 388267 [Patent Document 3] US Patent No. 8878880 [Patent Document 4] U.S. Patent No. 9245485 [Patent Document 5] European Patent No. 2054755 [Non-patent literature]

[0005] [Non-Patent Document 1] M.-M. Cheng, J. Warrell, W.-Y. Lin, S. Zheng, V. Vineet, and N. Crook, “Efficient salient region detection with soft image abstraction”, Proceedings of IEEE ICCV. IEEE, 2013, p. 1529-1536 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION The present invention aims to provide an improved system and method for displaying digital art images in a digital art frame. [Means for solving the problem]

[0007] The object of the present invention is solved by a method and system for displaying digital art images according to the independent claims.

[0008] Dithering the digital art image allows for a reduced number of intensity levels on the digital art frame's electronic paper display while still achieving high quality for the digital art image. Thus, the combination of electronic paper display and dithering can increase the quality of the digital art image and reduce the energy consumption of the digital art frame. Preprocessing the digital art image allows for more complex dithering that leads to increased quality for the digital art image. process Furthermore, the transfer of pre-processed digital art images to the digital art frame is fast and consumes minimal energy.

[0009] The object of the present invention is solved by a method for displaying a digital art image, the method comprising the steps of processing the digital art image to reduce a number of intensity levels of the digital art image to obtain a processed digital art image with a reduced number of intensity levels, transferring the processed digital art image to a digital art frame, and displaying the processed digital art image on an electronic paper display of the digital art frame.

[0010] The object of the present invention is solved by a system for displaying digital art images, comprising: a server; and a digital art frame, wherein the digital art frame comprises an electronic paper display having a number of intensity levels; the server is configured to store a plurality of processed digital art images, wherein the number of intensity levels of the processed digital art images is the same as the number of intensity levels of the electronic paper display; and the system is configured to transfer one of the processed digital art images to the digital art frame and display the transferred processed digital art image on the electronic paper display of the digital art frame.

[0011] The object of the present invention is solved by a digital art frame including an electronic paper display for displaying digital art images.

[0012] The object of the present invention is solved by a software program causing a processing means to perform the steps of processing a digital art image to obtain a processed digital art image for display on a digital art frame with an electronic paper display, and / or transferring the processed digital art image to the digital art frame and displaying the transferred digital art image on the electronic paper display of the digital art frame.

[0013] The dependent claims refer to further preferred embodiments.

[0014] In one embodiment, the digital art images stored on the server are dithered. process The image is dithered by

[0015] In one embodiment, the first digital art image is a first dithered image. process to obtain a first processed digital art image, and a second digital art image to obtain a second dithered digital art image. process The second processed digital art image is obtained by processing the first dithering process The second dithering process Unlike the first or second processed digital art image, the first or second processed digital art image is transferred to the digital art frame and displayed on the electronic paper display of the digital art frame. Therefore, for each digital art image, optimized dithering is performed to increase the quality of the processed digital art image displayed on the electronic paper display. process Beneficially, the first or second processed digital art image can be transferred to and subsequently displayed in the same digital art frame. In another embodiment, the first processed digital art image can be transferred to and displayed in a digital art frame, and the second processed digital art image can be transferred to a (separate) digital art frame and displayed in another digital art frame. Thus, in the latter embodiment, the first and second processed digital art images can be simultaneously displayed in different digital art frames.

[0016] In one embodiment, dithering process Dithering occurs differently in different image regions. process Apply multi-dithering processThere are many different dithering algorithms, each with many different dithering parameters. Generally, dithering increases image quality in areas by smoothly varying intensity, but most dithering algorithms also degrade edge quality. Therefore, for images with edges, dithering does not necessarily increase the quality of a digital art image. Multi-dithering allows for different dithering parameters to be applied to different areas of an image. process It is possible to apply the best dithering depending on the image content of each region. process Multi-dithering can be applied. process Multi-dithering of digital art images may include not applying multi-dithering to some areas. process will result in a multi-dithered digital art image. process may be different dithering algorithms and / or different dithering parameters of the same dithering algorithm. process may be an adaptive dithering algorithm in which the filter kernel varies depending on the content of the region of the digital art image being dithered.

[0017] In one embodiment, multi-dithering process selecting at least a first region and a second region as the various regions; and performing a first dithering process to the first area, and dithering process to the second region, process and second dithering process The first dithering process and second dithering process are different dithering process Alternatively, the first dithering process and second dithering process are the same dithering algorithm with different dithering parameters.

[0018] In one embodiment, the first dithering process is ordered dithering process and / or a second dithering process is error diffusion dithering process The combination of ordered dithering and error diffusion algorithms works particularly well: ordered dithering works well on edges and textured areas, and error diffusion dithering works particularly well for smooth intensity changes.

[0019] In one embodiment, the selection of different regions and / or different dithering of each of the different regions may be performed. process The selection is performed by the server, which enables automation of image processing without human intervention.

[0020] In one embodiment, multi-dithering process includes an adaptive dithering filter.

[0021] In one embodiment, dithering process includes an adaptive dithering filter.

[0022] In one embodiment, adaptive dithering process may depend on the position of the kernel in the digital art image and / or may include / use different filtering kernels in different regions of the digital art image. An adaptive filter may automatically adapt the filtering kernel to the region of application, avoiding the step of selecting different regions with different attributes.

[0023] In one embodiment, the filtering kernel depends on the intensity difference of pixels in the application region of the filtering kernel of the digital art image, which allows the filter kernel to be adapted based on the presence of edges in the application region.

[0024] In one embodiment, adaptive dithering processDithering (in various regions of a digital art image) based on features and / or the presence of edges process Therefore, this dithering process behaves more like the human eye, reducing the dithering effect at edges and / or process This increases the importance of characteristic regions in digital art images.

[0025] In one embodiment, dithering process and / or multi-dithering process Optimized dithering process Optimized dithering process Preferably, optimizes the dithering of the image based on a cost function.

[0026] In one embodiment, the digital art frame is mounted on a wall.

[0027] In one embodiment, the server is accessible to multiple users, each of whom controls at least one digital art frame.

[0028] In one embodiment, each user can access the server through user credentials, which are typically a username and password, but may also be hardware credentials such as a digital certificate, smart card, or NFC chip, or biometric credentials such as a fingerprint, voice recognition, retina scan, or facial recognition.

[0029] In one embodiment, each user can download / transfer the processed digital art image to one of the user's at least one digital art frame for display on the digital art frame's electronic paper display.

[0030] In one embodiment, each user has access to a user area on the server. The user area provides the user access to processed digital art images and allows management of the user's at least one digital art frame. Management of the user's at least one digital art frame (user management) allows the user to register the digital art frame, upload the user's digital art images to the user's digital art frame, and / or associate the digital art frame's location and / or orientation with the digital art frame. The user can also select one or more digital art images from a library of digital art images, which then become available in the user space. Registering a digital art frame in the user area specifies, for each registered digital art frame, details of the electronic paper display to be used with the digital art frame.

[0031] In one embodiment, the system includes a user's intermediary device, preferably configured to perform the user management described above, preferably connecting to the server via an Internet connection to perform the user management, and preferably serving as a user input for controlling the server.

[0032] In one embodiment, one of the users uploads an image to the server as a digital art image, and one of the user's at least one digital art frame receives the processed digital art image and displays the at least one digital art image on the electronic paper display of the digital art frame.

[0033] In one embodiment, the intermediary device is configured to select a processed digital art image on a server to be displayed in the digital art frame, and / or the (selected) processed digital art image is transferred to the digital art frame via an Internet connection.

[0034] In one embodiment, the digital art frame includes a first wireless communication interface for connecting to a local network, and the digital art frame is connected to the Internet via the local network. The local network is preferably a wireless local area network (WLAN). The digital art frame preferably includes a second communication interface for configuring the first wireless communication interface. The second communication interface is preferably a wireless communication interface. The second communication interface is preferably a Bluetooth connection.

[0035] In one embodiment, the processed digital art image is transmitted to the digital art frame via an intermediary device.

[0036] In one embodiment, the intermediary device includes software configured to perform one or more first operations, including allowing a user to select and download / transfer processed digital art images from a server to a digital art frame, automatically distributing multiple digital art images to multiple digital art frames, and detecting the orientation of the digital art frame on a wall. The intermediary device is preferably further configured to perform at least one second operation, preferably including configuring a first wireless communication interface of the digital art frame to connect to a local network. The intermediary device and / or its software are preferably configured to perform the one or more first operations with the server through the first communication interface and / or perform the one or more second operations with the digital art frame through the second communication interface.

[0037] In one embodiment, the orientation of the digital art frame is detected, and the digital art image is displayed on the electronic paper display according to the detected orientation of the digital art frame.

[0038] In one embodiment, the multiple processed digital art images are transferred to multiple digital art frames, and the processed digital art images are distributed to the multiple digital art frames according to the detected orientations of the digital art frames.

[0039] In one embodiment, a user can rotate the processed digital art image of the digital art frame, and the orientation of the digital art frame is detected based on a selected rotation orientation of the processed digital art image of the digital art frame.

[0040] In one embodiment, a user can rotate the processed digital art image of the digital art frame, and the orientation of the digital art frame is detected based on user input from the user.

[0041] In one embodiment, the orientation is detected by an orientation sensor in the digital art frame.

[0042] In one embodiment, the method / system includes a first digital art frame having a first electronic paper display and a second digital art frame having a second electronic paper display different from the first electronic paper display. The processing of the digital art image preferably includes a first processing of the digital art image to obtain a first processed digital art image and a second processing of the (same) digital art image to obtain a second processed digital art image. The processed digital art image preferably includes a first processed digital art image processed by the first processing of the digital art image and a second processed digital art image processed by the second processing of the digital art image. The first processing and second processing each reduce the number of intensity levels of the digital art image and dither the digital art image. processPreferably, the method includes: transferring the processed first digital art image to a first digital art frame and displaying it; and transferring the processed second digital art image to a second digital art frame and displaying it. This allows the image quality of the digital art image to be optimized for the details of the various electronic paper displays of the various digital art frames. The first processed digital art image is preferably different from the second processed digital art image. The first electronic paper display and the second electronic paper display preferably have different sizes, pixel counts, and / or resolutions. The first and second electronic paper displays preferably have the same number of intensity levels. The first processing of the digital art image and the second processing of the digital art image are preferably different. Dithering of the first processing of the digital art image process and dithering of digital art images for second processing process are preferably different.

[0043] In one embodiment, processing the digital art image includes comparing the digital art image and the processed digital art image.

[0044] In one embodiment, processing the digital art image includes displaying the processed digital art image on an auxiliary electronic paper display equivalent to the electronic paper display of the digital art frame, taking a photograph of the processed digital art image displayed on the auxiliary electronic paper display, and comparing the photograph to the digital art image.

[0045] In one embodiment, the processed digital art image is processed based on the comparison result to obtain an improved processed digital art image, and the improved processed digital art image is transferred to the digital art frame as the processed digital art image. In one embodiment, the processed digital art image is obtained by an optimization process based on the comparison result. The comparison result is a comparison result between the photograph and the digital art image and / or a comparison result between the processed digital art image and the digital art image. The comparison result is preferably based on the deviation of the photograph or the processed digital art image from the digital art image.

[0046] In one embodiment, the server performs the processing of the digital art images automatically.

[0047] In one embodiment, the electronic paper display includes 16 gray intensity levels, and the number of reduced intensity levels is 16.

[0048] In one embodiment, the digital art frame includes mounting means for mounting the digital art frame on a wall.

[0049] In one embodiment, the mounting means of the digital art frame includes a frame portion fixed to the digital art frame and a wall portion that is fixed to or is secured to a wall, and the frame portion allows the digital art frame to be removably secured to the wall portion in two directions, the two directions having a 90° difference, thereby allowing the orientation of the digital art frame to be quickly changed by 90°.

[0050] In one embodiment, the wall portion is preferably a hook and / or the frame portion is preferably a recess or hole in the housing of the digital art frame.

[0051] In one embodiment, the digital art frame includes wireless communication means configured to connect to a server over the Internet.

[0052] In one embodiment, the software program is executed by the server as the processing means.

[0053] In one embodiment, the software program is executed by the server and the intermediary device as the processing means.

[0054] In one embodiment, a software program is executed by the system as a processing means.

[0055] Other embodiments of the invention are set forth in the accompanying claims and in the following description. [Brief explanation of the drawings]

[0056] [Figure 1] FIG. 1 is a schematic block diagram of an embodiment of a system for displaying digital art images. [Figure 2] FIG. 2 is a schematic diagram of an embodiment of a server of a system for displaying digital art images. [Figure 3] FIG. 3 is a schematic block diagram of an embodiment of a digital art frame of a system for displaying digital art images. [Figure 4] FIG. 4 is a schematic block diagram of an embodiment of an intermediary device of a system for displaying digital art images. [Figure 5] FIG. 5 is a flow chart illustrating an embodiment of a method for displaying a digital art image. DETAILED DESCRIPTION OF THE INVENTION

[0057] In the drawings, the same or similar elements are designated by the same reference numerals.

[0058] Other characteristics and advantages of the invention emerge from the following non-limiting description, with reference to the drawings and examples.

[0059] 1 shows an embodiment of a system for displaying digital art images. The system includes a server 1 and a digital art frame 2. The system may optionally include an intermediary device 3.

[0060] The digital art image is preferably a digital art image configured for display on a digital display. The digital art image may be a color image or a grayscale image. The digital art image has a number of intensity levels. Preferably, the number of intensity levels in the digital art image is 256 or more. For color images, each color (e.g., red, green, and blue) has a corresponding number of intensity levels. The digital art image has image characteristics such as pixel count, size ratio, etc. The digital art image can include any type of image that is displayed on a display. However, the digital art image preferably includes a user's art image and / or photograph, such as a family photo. Also, the art image is preferably photographic art, although other art images are possible. The digital art image preferably does not include any text, although it is possible for the digital art image to (possibly) include text.

[0061] The digital art frame 2 includes an electronic paper display 21 (also referred to as an electronic ink display). The digital art frame 2 preferably includes one or more of an attachment means 22, a first communication interface 23, a power supply means 24, an orientation sensor 25, a controller 26, a second communication interface 27, and a user input means 28. Figure 3 shows an embodiment of the digital art frame 2.

[0062] The digital art frame 2 preferably includes a first planar side and a second planar side. The first planar side is positioned opposite the second planar side. The digital art frame 2 is preferably configured to be attached to a wall by the second planar side and display a digital art image on the first planar side. The digital art frame 2 is preferably a rectangle having four sides. The four sides preferably include a first side, a second side opposite the first side, a third side, and a fourth side. The first side is preferably parallel to the second side and perpendicular to the third and fourth sides. The third side is preferably parallel to the fourth side and perpendicular to the first and second sides. However, the digital art frame 2 may have other shapes.

[0063] The electronic paper display 21 is configured to display images, particularly digital art images after processing as described below. Electronic paper displays 21 refer to displays in which the displayed image is visible to the user by light reflection and / or does not actively emit light like classical emissive displays. The electronic paper display is preferably an electrophoretic display. However, other electronic paper display technologies can also be used. The electronic paper display 21 preferably has a number of intensity levels that can be displayed by the display 21. The electronic paper display 21 is preferably a gray level display, i.e., the electronic paper display 21 displays only gray levels and / or does not display color. However, in the future, color electronic paper displays 21 configured to display various color levels can be used. The electronic paper display 21 is preferably configured to display at least 4, preferably at least 8, and preferably at least 16 different (gray) intensity levels. The electronic paper display 21 is preferably configured to display 128 or fewer intensity levels, preferably 64 or fewer intensity levels, and preferably 32 or fewer intensity levels. Preferably, electronic paper display 21 is configured to represent 16 (gray) intensity levels and / or display 4-bit images. Electronic paper display 21 is defined by display characteristics such as pixel count, size, and / or pixel density. The pixel count is preferably a tuple of the number of pixels in the x direction and the number of pixels in the y direction. However, the pixel count may be the total number of pixels. The size may be the diagonal of the display. Alternatively, the size may be a tuple of the size in the x direction and the size in the y direction. Electronic paper display 21 is positioned on digital art frame 2 such that it is viewable by a user on a first planar side of digital art frame 2, and / or electronic paper display 21 is positioned on the first planar side of digital art frame 2.

[0064] The digital art frame 2 preferably includes mounting means 22. The mounting means 22 is configured to secure the digital art frame 2 to a wall. The mounting means 22 is preferably disposed on a second planar side of the digital art frame 2, which includes the electronic paper display 21. The mounting means 22 preferably includes a wall portion and a frame portion. The frame portion is secured to the digital art frame 2. "Secured" may also mean that the frame portion is integrally formed by the housing of the digital art frame 2. The wall portion is configured to be secured to the wall. The mounting means 22 is configured to rotate the orientation of the digital art frame 2 by 90 degrees. The orientation of the digital art frame is a rotational state of the digital art frame 2 about the vertical axis of the electronic paper display 21, and rotating the digital art frame 2 by 90 degrees rotates the orientation of the electronic paper display 21 by 90 degrees. Thus, the digital art frame can be rotated to change the display orientation from landscape to portrait, and vice versa. The mounting means 22 is preferably configured so that the orientation of the digital art frame 2 can be changed by 90° by rotating the wall portion 90° relative to the frame portion. The frame portion of the digital art frame 2 and / or the mounting means 22 can preferably be removably fixed to the wall portion. The frame portion can preferably be fixed to the wall portion in two orientations with an orientation difference of 90°, so that two orientation states of the digital art frame 2 are obtained. In this manner, to change the orientation of the digital art frame 2 hanging on the wall, the digital art frame 2 with the frame portion is removed from the wall portion, rotated 90°, and re-fixed in the new orientation. In one embodiment, the mounting means 22 ensures that the orientation angle between the digital art frame 2 and / or the frame portion and the wall portion is not between 0° and 90°. The mounting means 22 with the frame portion and wall portion allows for easy and stable mounting of the digital art frame 2 to the wall. When the digital art frame 2 with the frame portion is fixed to the wall portion, the wall portion is preferably attached so that the sides of the digital art frame 2 are vertical and / or horizontal.Therefore, it is not necessary to level the digital art frame 2 when changing the orientation of the digital art frame 2. For example, the frame portion and the wall portion can interact in a form that fits snugly together. The wall portion can be a male portion, such as a hook, and the frame portion can be a female portion that receives the male portion.

[0065] The digital art frame 2 preferably includes a first communication interface 23 configured to communicate with the server 1 and / or receive images to be displayed on the electronic paper display 21. The first communication interface 23 is preferably connected to the server 1 via the Internet 4. The first communication interface 23 is preferably a wireless communication interface, allowing processed digital art images to be received wirelessly from the server 1. The wireless communication interface 23 is preferably a wireless communication interface. However, optical communication, such as infrared communication, can also be used. The wireless communication interface is preferably connected (or configured to be connected) to a local network. The first communication interface 23 is preferably connected to the Internet 4 via the local network (connected to the server 1 via the Internet 4). The local network is preferably a WLAN network. However, the local network may be another network protocol, such as a WAN, a low-power wide-area network (LPWAN) such as LoRa (LoRa), or any other local network. However, the first wireless communication interface 23 may also be connected (or configured to be connected) to a cellular network (to the Internet 4 and the server 1 via the cellular network). The cellular network may be a mobile phone network such as GSM, 3G, 4G, 5G or other cellular IoT network.

[0066] The digital art frame 2 preferably includes a second communication interface 27 configured to communicate with an intermediate device 3. The second communication interface 27 is preferably a wireless communication interface 27 configured to communicate with an intermediate device 3 in the digital art frame 2's physical vicinity. The wireless communication interface 23 is preferably one or more of Bluetooth, a wireless local area network (WLAN), a near field communication (NFC), etc. The wireless communication interface 23 may also be a communication protocol for the Internet of Things, such as a low-power wide area network (LPWAN) such as Long Range Access (LoRa). The digital art frame 2 is preferably configured to receive configuration information for configuring the first communication interface 23 via the second communication interface 27. The configuration information is preferably configured to configure the first communication interface to connect to a local network and / or the Internet 4 and / or a server 1. The digital art frame 2 is preferably further configured to configure the first communication interface 23 based on the configuration information.

[0067] In a preferred embodiment, the first communication interface 23 and the second communication interface 27 are preferably separate and / or different. However, in alternative embodiments, it is possible to use the same communication interface for the above-mentioned functions of the first and second communication interfaces 23 / 27. In less preferred embodiments, it is also possible to use just the first communication interface 23 (e.g., if connection setup is not required or can be done directly on the digital interface, e.g., with the user input means 28) or just the second communication interface 27 (e.g., when receiving images via the user's intermediate device 3).

[0068] To conserve power, the wireless communication interface 23 may include a switch that powers on the wireless communication interface 23 only when needed. The switch can switch the first communication interface 23 from standby mode to operating mode, or from power-off mode to operating mode. The switch may be a switch on the digital art frame 2 that is activated by a user input from the user input means 28, such as a power button on the digital art frame 2. The switch may also be activated by a radio signal of the wireless communication protocol of the wireless communication interface 23 itself, such as a signal that switches the wireless communication interface 23 from standby mode to operating mode before receiving an image to be displayed on the digital art frame. The switch may be implemented by a transponder in the wireless communication interface 23 such as an NFC transponder that receives power from the transponder signal to the switch. The switch can also be operated by time management by the controller 26. In this case, the switch powers on the first communication interface 23 to connect to the server 1 to see if there are any new messages waiting for the digital art frame 2. In this case, the digital art frame 2 processes the message waiting for the digital art frame 2, and after processing this message, the first communication interface 23 is again turned off. Otherwise, the first communication interface 23 is turned off. The interval between connections to the server or between the power-on states of the switch is preferably greater than 1 second, preferably greater than 10 seconds, preferably greater than 30 seconds, preferably greater than 60 seconds, and preferably greater than 5 minutes. Longer intervals, such as greater than 10 minutes, greater than 30 minutes, or greater than 60 minutes, can also be applied. Switch control embodiments can also be combined. For example, switch time management can be combined with the user input means 28. This allows for a long connection interval to be used to automatically connect to the server 1, and (if the connection is urgent) the connection to the server 1 can be switched on and off by input via the input means 28, for example, a start button.

[0069] The same switching can be applied to the second communication interface 27 as to the first communication interface, and the explanation will be omitted.

[0070] The power source 24 is configured to provide power for operating the digital art frame 24. The power source 24 is preferably a battery. The battery may be a rechargeable battery, such as a lithium-ion battery. However, the battery could also include one or more non-rechargeable, replaceable batteries. Additionally or alternatively, the power source could include a renewable energy source, such as a solar panel, to recharge the battery or provide direct power. The power source 24 is preferably self-sufficient (at least for a time) and / or does not require connection to a power grid via a cable. This facilitates wall mounting of the digital art frame 2. The digital art frame 2 may also be connected to a power grid or any other power source via a cable to recharge the battery of the digital art frame 2 when the battery is discharged.

[0071] The orientation sensor 25 is configured to detect the orientation of the digital art frame 2 and transmit the detected orientation (via the wireless communication interface 23) to the intermediary device 3 and / or the server 1. For example, the orientation sensor 25 may be a magnetic sensor. However, the orientation sensor 25 is optional.

[0072] The digital art frame 2 preferably includes a controller 26. The controller 26 is preferably configured to control the operation of the digital art frame 2 and all of its elements. The controller 26 preferably controls the electronic paper display 21, the wireless communication interface 23, and / or the orientation sensor 25. The digital art frame 2 and / or the controller 26 are preferably configured to receive an image, particularly a processed digital art image, and display the received image on the electronic paper display 21. The digital art frame 2 preferably receives a direction via the wireless communication interface 23 along with the image to be displayed. The digital art frame 2 and / or the controller 26 are preferably configured to display the received image on the electronic paper display 21 according to the received direction.

[0073] The digital art frame 2 preferably includes a user input means 28. The user input means 28 is configured to receive user input to the digital art frame 2. In a preferred embodiment, the user input means 28 is quite simple, for example a button that simply activates the digital art frame 2, with other user input being received via the first and / or second communication interface 2. However, it is also possible to receive more user input via the user input means 28. For example, configuration information for the first communication interface 23 could be received via the user input means 28 (instead of the second communication interface 27).

[0074] The system preferably includes a plurality of digital art frames 2, as described above. The plurality of digital art frames 2 and / or the system may include a plurality of types of digital art frames 2. The various types of digital art frames 2 preferably include various electronic paper displays 21 with various characteristics of the electronic paper displays 21 for the various types of digital art frames 2. The electronic paper displays 21 of the various types of digital art frames preferably differ in size and / or pixel count. The various types of digital art frames preferably include a first digital art frame 2 of a first type and a second digital art frame 2 of a second type, where the first digital art frame 2 has an electronic paper display 21 with a first characteristic and the second digital art frame 2 has an electronic paper display 21 with a second characteristic different from the first characteristic. The electronic paper displays 21 of the first and second digital art frames preferably differ in size, pixel count, and / or pixel density. The plurality of digital art frames 2 are preferably owned by or under the control of various users. Each user preferably owns at least one digital art frame 2. Some users may own multiple digital art frames 2. The multiple digital art frames 2 may be associated with various groups, with each group including at least one digital art frame 2. For example, each group may be associated with a common location, such as a first group for the living room, a second group for the kitchen, and a third group for the office.

[0075] Server 1 is a computing configuration configured to provide the above-described functions of Server 1. Server 1 can be realized by one or more computing devices. Server 1 may be a physical computing configuration, such as one or more servers or server configurations. Server 1 may also be a virtual server, such as a cloud server typically provided by a cloud provider that provides a specific server service. A server can be distributed through various virtual and / or physical computing configurations. Server 1 may have various sub-servers. Various functions of Server 1 can be handled by various sub-servers of Server 1, and the sub-servers are independent of each other. The various sub-servers can provide the same functions of Server 1 to provide backup capacity or increase capacity.

[0076] Server 1 is configured to provide at least one, and preferably multiple, processed digital art images. Server 1 preferably includes database 11 that stores the multiple processed digital art images. For ease of explanation, database 11 is described as being part of server 11. This includes the possibility that database 11 may be connected to server 1 via the Internet or another network. Figure 2 shows an embodiment of server 1. Database 11 preferably stores one or multiple versions of the or each digital art image.

[0077] The following describes the terminology used for digital art images. The term "digital art image" refers to all versions of a digital art image that show the same image, but may have different image characteristics, such as the number of intensity levels or the number of pixels. The general use of "digital art image" includes all possible options or versions of a digital art image, unless it is specifically stated that a particular digital art image is intended. A first version of a digital art image is the "received digital art image" or "original digital art image." The received / original digital art image refers to the digital art image received for display on the digital art frame 2. The received / original digital art image may have been processed with a small number of pre-processing steps (but not a reduction in the number of intensity levels). A second version of a digital art image is the "processed digital art image." The processed digital art image is received through image processing of the received / original digital art image and / or is optimized for the electronic paper display 21 of the digital art frame 2. In particular, the processed digital art image may have a reduced number of intensity levels compared to the received / original digital art image and / or may have undergone dithering. processAs described above, there may be various versions of the processed digital art image. Another version of the digital art image may be a selected digital art image. The selected digital art image is the version of the digital art image displayed on the intermediary device 3 when the digital art image is selected for display on the digital art frame 2. The selected digital art image may be the received / original digital art, the processed digital art image, or a different version of the digital art image that is different from the received processed digital art image. Database 11 preferably stores various versions of the digital art image. Database 11 always stores the processed digital art image. Additionally, database 11 preferably stores other versions of the processed digital art image that are optimized for different digital art frames 2. Additionally, database 11 preferably stores the received / original digital art image. Additionally, database 11 preferably stores the selected digital art image (if different from other digital art images stored in the database). Database 11 may include various sub-databases that each store various versions of the digital art image.

[0078] In one embodiment, the server 1 / database 11 stores different processed digital art images optimized for the respective characteristics of the electronic paper display 21 for different types of digital art frames 2 with different characteristics of the electronic paper display 21. The different processed digital art images for the different types of digital art frames 2 reference and / or represent the same (original) digital art image, but are processed separately to optimize the processed digital art image for each type of digital art frame. Thus, a first processed digital art image and a second processed digital art image represent substantially the same content of the same digital art image. The first processed digital art image is processed separately from the second processed digital art image. The first processed digital art image is processed to optimize for the characteristics of the electronic paper display 21 of the first digital art frame, and the second processed digital art image is processed to optimize for the characteristics of the electronic paper display 21 of the second digital art frame 2. This allows for high-quality optimization of the digital art images and fast response times for downloading / transferring the processed digital art images to each digital art frame 2.

[0079] Server 1 preferably includes a communications interface 12. Communications interface 12 is configured to transfer the processed digital art image from server 1 / database 11 to digital art frame 1. Communications interface 12 is preferably connected to Internet 4. Server 1 is preferably connected to intermediary device 3 and / or digital art frame 2 via communications interface 12 (Internet 4). Communications interface 12 is preferably further configured to receive the digital art image to provide the processed digital art image.

[0080] The server 1 preferably includes image processing means 13 configured to process the received digital art image to obtain a processed digital art image. The processing to obtain the processed digital art image is described in more detail below. In one embodiment, the digital art image is processed with a first processing to obtain a first processed digital art image for a first digital art frame, and the digital art image is processed with a second processing to obtain a second processed digital art image for a second digital art frame. The first and second processing are preferably different. The first and second processed digital art images are preferably different (even if they represent the same content of the digital art image). The following description regarding the processing of the digital art image equally applies to the first and second processing, which preferably differ only in one or more parameters.

[0081] In one embodiment, image processing means 13 is configured to fully automatically obtain a processed digital art image from a digital art image. In another embodiment, image processing means 13 is configured to semi-automatically obtain a processed digital art image from a digital art image. In this embodiment, human intervention is required to obtain the processed digital art image. Human intervention may be limited to some digital art images with insufficient quality by automating the quality checks of image processing means 13. Human intervention may also be required for each digital art image, for example, to select areas of the digital art image to which image processing techniques are applied.

[0082] The server 1 preferably includes a controller 14. The controller 14 is preferably one or more central processing units (CPUs) that execute programs for controlling the server 1.

[0083] In one embodiment, server 1 includes quality check configuration 15. Specifically, quality check configuration 15 is connected to the computing configuration of server 1. For ease of explanation, quality check configuration 15 is described as part of server 1. Quality check configuration 15 preferably includes an auxiliary electronic paper display and a digital photo camera. The auxiliary electronic paper display preferably has the same display characteristics as auxiliary paper display 21 of digital art frame 2. The auxiliary electronic paper display may be realized by digital art frame 2 that is identical to the user's digital art frame. The digital photo camera is positioned to capture a photograph of the auxiliary electronic paper display. Quality check configuration 15 receives the processed digital art image, displays the processed digital art image on the auxiliary electronic paper display, and takes a photograph of the processed digital art image displayed on the auxiliary electronic paper display. This photograph can be used to determine the quality of the processed digital art image by comparing the photograph with the (original) digital art image. The comparison result can be used to determine the quality of the processed digital art image and / or as feedback for an image processing algorithm, such as an optimization image processing algorithm or an iterative image processing algorithm.

[0084] The intermediary device 3 is preferably configured to access digital art images from the server 1 and / or transfer digital art images from the server 1 to the digital art frame 2. The intermediary device 3 preferably includes a first communication interface 31, a second communication interface 32, a controller 33, and / or a user interface 34. FIG. 4 shows an embodiment of the intermediary device 3. The intermediary device 3 is preferably a general computing device such as a computer, a smartphone, a tablet, or a portable computer. The intermediary device 3 can be realized by these various devices. For example, the same client application software can run on a user's tablet, smartphone, and computer, and the user can decide which intermediary device 3 to select for any function the user prefers.

[0085] The first communication interface 31 is configured to communicate with (the communication interface 12 of) the server 1. The first communication interface 31 is preferably a communication interface 31 for establishing a connection with the Internet 4, such as a WLAN, a mobile phone interface or others.

[0086] The second communication interface 32 is configured to communicate with the digital art frame 2 (its wireless communication interface 23). The second communication interface 32 is preferably a wireless communication interface such as WLAN or Bluetooth. However, the second communication interface 32 may also be a wired communication interface, for example, a LAN interface, connected via a router to the WLAN to which the digital art frame 2 is connected. The second communication interface 32 preferably follows the same communication protocol as the wireless communication interface 23 of the digital art frame 2.

[0087] The controller 33 is configured to control the intermediary device 3. The intermediary device 3 and / or the controller 33 are preferably configured to access the server 1 to select processed digital art images to be transferred to the digital art frame 2 and / or to perform other functions of the system. The controller 33 is preferably a general computing means such as a CPU. The functions of the system of the intermediary device 3 are preferably realized by a software program running on the CPU of the intermediary device 3. The software program may be a browser that interacts with a server program running on (the controller 14 of) the server 1. The software may be a dedicated software application for the system. The dedicated software application may be a front-end for the server program (client software) that runs the server 1, or may be an independent software application (desktop software).

[0088] The user interface 34 preferably includes a visual output means, preferably a display. The user interface 34 preferably includes an input means, such as a mouse, keyboard, touch screen or any other means.

[0089] The system preferably includes multiple users. A standard user owns at least one digital art frame 2 and preferably an intermediary device 3. Users are preferably registered with the system. Each user preferably has access to the system through user credentials, such as a username and password combination. The operations a user can perform on the system software are the same for all users and are instantiated only once for each user. There may be some minor differences in the functionality of various users. For example, some users may have fewer digital art images than other users (e.g., users under a certain age). There may be special users who do not own a digital art frame but who only upload digital art images for processing, which are then provided to other users as processed digital art images to be displayed on their digital art frames 2. For such users, only the functionality described below related to uploading digital art images is important.

[0090] The system preferably includes a system software program that preferably runs on (the controller 14 of) the server 1 with a front end provided by a browser or client software application on the intermediary device 3. However, some functions of the system software related to user operation may be realized by user software running on the intermediary device 3.

[0091] The system software allows users of the system one or more of the following functions: -Selecting the processed digital art image to be displayed on the user's digital art frame 2. -Transferring the processed digital art image from the server 1 to the intermediary device 3 and / or the digital art frame 2. - Registering the user's digital art frame 2 in the user's user space. - Delivering various processed digital art images to various digital art frames 2 of users. - Uploading a digital art image to be processed to the server 1 to obtain a processed digital art image (which can be transferred to the digital art frame 2 for selection and / or display). -Detect the orientation of the wall digital art frame 2.

[0092] The system (software) is preferably configured to allow a user to access a database 11 storing digital art images. The user can preferably access the database 11 through an intermediary device 3. The user can preferably search through a list of digital art images and select one or more digital art images to display in one or more of the user's at least one digital art frame 2. The user can also select groups of digital art images, such as those grouped by a common theme or keyword. When selected, the digital art images are preferably displayed on the intermediary device 3. The selected digital art images are preferably displayed to the user, so that the user can view the digital art images on the visual output means of the intermediary device 3. The user can manually, semi-automatically, or automatically select the digital art images to display in the user's at least one digital art frame 2. In manual selection, the user selects digital art images from the database 11 for one of the user's at least one digital art frame 2. In semi-manual selection, the user selects several criteria, such as theme, keywords, popularity, etc., and the system (software) selects the best images based on the selected criteria. The selected criteria may be a single criterion. In fully automatic selection, the system (software) freely selects for the user. The system (software) may use user profile information, such as hobbies, demographic data, and image selection history, when automatically selecting an image. The user's selection (in manual or semi-automatic selection) may be made when changing the digital art image in the digital art frame and may be saved for future changes to the digital art frame. The timing of changing the digital art image in the digital art frame 2 may also be determined automatically, for example, by a previous user selection or by periodic changes, such as weekly or monthly. This is referred to as the selected digital art image, regardless of when and how the digital art image is selected.The selected digital art image does not refer to a particular version of the digital art image, but rather to the digital art image itself; i.e., the content of the digital art image, regardless of the version of the digital art image, is used to select the digital art image.

[0093] The system (software) is preferably configured to transfer the processed digital art image from the server 1 to the digital art frame 2. The processed digital art image of the selected digital art image is preferably transferred to the digital art frame 2. If there are multiple versions of the processed digital art image, the version of the processed digital art image that is optimized for the user's digital art frame 2 is transferred to the digital art frame 2. In a preferred embodiment, the processed digital art image is transferred directly from the server 1 to the digital art frame 2 (without going through the intermediary device 2). This is preferably achieved via an Internet connection 4 and a local network through which the digital art frame 2 is connected to the Internet 4. In a less preferred embodiment, transferring the processed digital art image from the server 1 to the digital art frame 2 refers to transferring / downloading the processed digital art image from the server 1 to the user's digital art frame 2 via the user's intermediary device 3. The communication connection between the digital art frame 2 and the server 1 may be initiated by a user input at the user input means 28 of the digital art frame 2, by powering on the wireless communication interface 23.

[0094] The system (software) is preferably configured to register at least one digital art frame 2 of a user in the user's user space. The user space preferably registers the type of digital art frame for each of the at least one digital art frame 2. This allows the system (software) to recognize the type of each digital art frame 2 on which the selected / processed digital art image will be displayed, and allows the system (software) to transfer the processed digital art image optimized for each digital art frame 2 to each digital art frame 2. The at least one digital art frame preferably includes multiple digital art frames. The multiple digital art frames are preferably associated with various groups. A first group preferably includes at least one first digital art frame 2 of the user's multiple digital art frames 2, and a second group preferably includes at least one second digital art frame 2 of the user's multiple digital art frames 2. The groups can be associated with various locations, for example, for wall mounting. This allows the system (software) to select similar selection criteria for each group of digital art frames 2, through semi-automatic or automatic selection.

[0095] The system (software) is preferably configured to deliver various processed digital art images to the user's various digital art frames 2. The various processed digital art images are selected by automatic, semi-automatic, or automatic selection. The system (software) is preferably configured to deliver the selected digital art images to the user's various digital art frames 2 based on the orientation of the digital art frames 2 and the digital art images. The system (software) is preferably configured to deliver the selected digital art images to the user's various digital art frames 2 based on the grouping of the digital art frames 2.

[0096] The system (software) is preferably configured to upload a digital art image to the server 1 for image processing to obtain a processed digital art image. Thus, the uploaded digital art image corresponds to the original / received digital art image (with a small amount of pre-processing). The uploaded digital art image is processed to obtain the processed digital art image. The user uploading the digital art image can decide whether the uploaded digital art image is for private use or for other users (public use or semi-public use). In the case of private use, the processed digital art image of the uploaded digital art image is available only to the uploading user for transfer and / or display on at least one of the user's digital art frames 2. In the case of public use, the processed digital art image of the uploaded digital art image is available to all users of the system. In the case of semi-public use, the processed digital art image of the uploaded digital art image is available to a subgroup of users of the system, for example, one or more specially selected users or a standard subgroup of users. The uploading user (or another user in the case of public or semi-public use) can then select a processed digital art image of the uploaded digital art image, transfer it to the user's digital art frame 2, and display it on the digital art frame 2.

[0097] The system (software) is preferably configured to detect the orientation of the digital art frame 2 on the wall. In one embodiment, the orientation of the digital art frame 2 is detected based on an orientation sensor in the digital art frame 2. In one embodiment, the orientation of the digital art frame 2 is detected based on user input. The user input for detecting the orientation may be provided by the intermediary device 3 and / or the digital art frame 2. The user input is preferably a selection of the orientation of the digital art frame 2 or a change in the orientation of the digital art image in the digital art frame 2. The detected orientation of the digital art frame 2 is preferably registered with each digital art frame 2 so that the system knows that a digital art image in a first orientation should (preferably) be delivered to a digital art frame 2 in a first orientation and a digital art image with a second orientation should (preferably) be delivered to a digital art frame 2 in a second orientation.

[0098] The above-described functions and elements of the system are similarly applicable to the method, and the description of the method will not be repeated in its entirety, but will be simplified accordingly.

[0099] An embodiment of the method of the present invention is shown in FIG.

[0100] The method includes a step S1 of processing a digital art image. The received / original digital art image is preferably processed (is an image) to obtain a processed digital art image. The image processing includes a reduction in the number of intensity levels (of pixels), such that the number of intensity levels of the processed digital art image is reduced from the number of intensity levels of the original digital art image. The original digital art image includes the original number of intensity levels, and the processed digital art image has the processed number of intensity levels. The processed number of intensity levels is preferably equal to the number of intensity levels of the electronic paper display 21 of the digital art frame 2. The processed number of intensity levels is preferably at least 4, preferably at least 8, and preferably at least 16. The processed number of intensity levels is preferably 128 intensity levels or less, preferably 64 intensity levels or less, preferably 32 intensity levels or less. The processed number of intensity levels is preferably equal to 16. Hereinafter, the process of reducing the number of intensity levels will be referred to as intensity level reduction processing.

[0101] Image processing and / or intensity level reduction processes include dithering process Preferably, the method includes: process The intensity levels, together with the other intensity levels, are selected from the number of intensity levels in the processed image to approximate the intensity levels of the pixels in the original digital art image in the dithered image or processed digital art image. processdetermines an intensity value of a (target) pixel of the processed digital art image based on (the intensity level of) a corresponding (target) pixel in the original digital art image and based on (the intensity level of) at least one further pixel of the original and / or processed digital art image surrounding the corresponding (target) pixel. A target pixel is defined as any pixel in the image at a distinct location in the currently represented image. The target pixel of the original digital art image is at the same location as the target pixel in the processed digital art image. The same location refers to a relative location in the images. If the pixel sizes of the original and processed images are the same, the absolute pixel location (and relative location) will be the same. If the pixel sizes of the original and processed images are different, the same location does not refer to absolute pixel location, but rather to a relative location. Dithering according to the present invention is not intended to include algorithms that select intensity levels of pixels in the processed digital art image solely based on the respective intensity levels of each pixel in the original digital art image and / or do not also consider surrounding pixels in the original digital art image. Then, in addition to the target pixel, at least one other pixel near the target pixel is referred to as the target pixel's surrounding pixel. The surrounding pixels are typically defined by the dithering algorithm and / or dithering used. process However, the image processing may include an intensity level reduction process in the combined processing. process It is also possible to include dithering as a separate or independent process. process "Dithering the (Original) Digital Art Image" can be applied to the original digital art image or to a pre-processed version of the original digital art image. For example, pre-processing may include changing the pixel count and / or size of the digital art image and / or other pre-processing steps. process The phrase "dithering" process This does not exclude that other preprocessing steps may be performed on the (original) digital art image before is applied to the preprocessed (original) digital art image.

[0102] There are hundreds of dithering algorithms, each with its own advantages and disadvantages. One dithering algorithm may be suitable for one digital art image, while another dithering algorithm may be suitable for another digital art image. Thus, in one embodiment, a first digital art image is generated using a first dithering algorithm. process The first processed digital art image is processed by dithering the first digital art image. The second digital art image is processed by dithering the first digital art image. process and different second dithering process The second processed digital art image is processed by two different dithering process is two different ditherings on the same image process By applying two different dithering methods, the two images are processed in two different ways. process may be different for different dithering algorithms and / or different dithering parameters. As will be described later, process may be applied to different regions of an image with different dithering algorithms and / or parameters. For example, the same dithering algorithm with the same dithering parameters applied to two images in different regions of the image may be considered two different dithering algorithms. process Correct dithering for each digital art image process The selection of dithering is preferably based on the content of the digital art image, preferably the original digital art image. process The use of the RGB color filter increases the quality of the processed digital art image.

[0103] In a preferred embodiment, dithering of the (original) digital art image process multi-dithering of the (original) digital art image to obtain the processed digital image process Includes multi-dithering of digital art images processApply different dithering to different areas of the digital art image to obtain the processed digital art image. process applies.

[0104] In one embodiment, multi-dithering process selecting various regions and performing dithering on each of the selected various regions. process and for each of the various selected regions, applying a selected dithering effect to that region of the digital art image. process and applying the best dithering to each region of the digital art image. process Select Dithering process It is possible to obtain satisfactory results.

[0105] The selection of the various regions of the digital art image is based on the content of the digital art image. The various regions preferably have different locations on the digital art image and / or do not overlap one another. The various regions preferably differ in size and / or shape. Each region is selected based on at least one common image characteristic, such as the presence of edges, smoothness, intensity variations, etc. The digital art image may have different dithering effects in the various regions. processBecause some digital art images have the same image characteristics that do not require selection, it is conceivable that some digital art images will result in a single region covering the entire digital art image upon selection. Thus, the various regions may include cases where there is a single region covering the entire digital art image, but may also include cases where an active selection process is involved to decide between a single region and two or more various regions. The selection of the various regions of the digital art image can be performed automatically, semi-automatically, or manually. Preferably, the server 1 analyzes the digital art image and selects the various regions of the digital art image (fully automatically) based on the previous analysis. However, the selection of the various regions can also be performed manually by image processing software (manually). A combination of both (semi-automatically) is also possible. For example, the server 1 may automatically suggest a selection of various regions that can be modified manually (if necessary).

[0106] Dithering for each of the various selected regions process The selection of the dithering order is based on the content of the respective region. In one embodiment, the first region is selected as the dithering order. process is used, and error diffusion dithering is used in the second region. process is used. process replaces a pixel or group of pixels with a pixel pattern. The pixel pattern depends on the intensity level of the pixel or group of pixels being replaced. Different intensity levels are associated with different patterns that result in each intensity level. The same intensity level is always replaced by the same pixel pattern. Ordered Dithering process It is clear that the above number of intensity levels of the processed digital art image is very effective for images or areas with structure and edges. Examples of ordered dithering algorithms are halftone dithering, Bayer dithering, and error diffusion dithering. processDiffuses quantization errors (caused by quantization of the number of intensity levels after reduction of the processed digital art image) to surrounding pixels. Examples of error diffusion dithering algorithms are Floyd-Steinberg dithering, minimum mean error dithering, Stucki dithering, and Burkes dithering. Error Diffusion Dithering process It is clear that the above number of intensity levels of the processed digital art image is very effective for images or regions where the intensity changes are smooth. In regions with many edges and structures, it is preferable to use an ordered dithering algorithm, and in regions where the intensity changes are smooth, it is preferable to use a diffused error algorithm. For one of the regions, for example, for a continuous surface of intensity levels that can be displayed by an electronic paper display, the selected dithering algorithm process may not use a dithering algorithm. However, in this case, at least one other region may use a dithering algorithm. process Dithering must be applied process Instead of dithering process The server 1 analyzes each region of the digital art image and applies each dithering technique to that region of the digital art image based on the previous analysis. process However, it is preferable to select the dithering for each region. process The selection of the dithering factor can be performed by a person via image processing software (manually) or by a combination of both (semi-automatically). For example, the server 1 may select a dithering factor for each region, which can be modified by a person (if necessary). process The user may automatically suggest a choice of

[0107] Also, the area and the dithering for that area process The steps of selecting may be combined. For example, the server 1 may select various dithering processand comparing the resulting variously dithered digital art images with the original digital art image. For example, the comparison result may be an absolute difference image or a squared difference image between the two images. process Based on the results of various comparisons, Server 1 determines the area and its dithering process For example, a first dithering in a first region may be selected. process If the best result is obtained, the comparison result of the area is the best result, and the second dithering process gives the best results in the second region. Therefore, Server 1 uses the first dithering process , the second area has the second dithering process You will have to select:

[0108] Then, various dithering options are selected. process is applied to various selected areas of the digital art image. Each selected area of ​​the digital art image is assigned a dithering value selected for that area. process Apply region and / or dithering process The selection process is performed by selecting the selected area and then dithering it. process If one or more applications of the .log file are included, the results of these applications can be used in this step. process Before selecting the application step, in some instances, an application step may be executed. The application step is preferably executed by the server 1.

[0109] In one embodiment, multi-dithering process or dithering process includes adaptive dithering (filtering) processes, which have a filtering kernel that adapts to the application area of ​​the filter kernel. processchanges the filtering / dithering method based on the area the filter is applied to. This is the filter kernel for dithering (filtering) operations, or process is different in different areas of the digital art image, so different dithering is required in different areas of the digital art image. process means to apply a filtering kernel or dithering process may depend on the presence of edges in the digital art image and / or on the characteristics of the pixel. The presence of an edge can be detected by the intensity difference of pixels surrounding the pixel. For example, the filtering kernel for each surrounding pixel may depend on the intensity difference between the surrounding pixels in the (original) digital art image and the target pixel in the (original) digital art image. Thus, for example, the quantization error of the target pixel can be shifted to surrounding pixels with smaller intensity differences (and therefore similar intensity levels) rather than pixels with higher intensity differences (and therefore more different intensity levels). Such adaptive filter kernels can be integrated into classical error diffusion algorithms. Below, we will discuss such adaptive dithering process The example of the above will be explained in more detail.

[0110] Ordered dithering and error diffusion algorithms were discussed above. There are many more dithering algorithms. Most dithering algorithms need only be run once on a digital art image to obtain a resulting digital art image. For example, every pixel or group of pixels in the digital art image is replaced by a specific pixel pattern that depends on the intensity value of the replaced pixel or group of pixels (ordered dithering algorithm). In another example, the quantization error of each pixel is diffused to surrounding pixels not processed by the dithering algorithm (error diffusion algorithm). However, there are also more advanced dithering algorithms or filters that attempt to optimize the global dithering problem by optimizing the resulting digital art image based on a cost function. Examples of such cost functions are:

[0111]

number

[0112] where i denotes an index covering all N pixels of the digital art image. Index j covers all pixels of the nearest pixel Ni. The nearest pixels Ni of a target pixel i do not include the target pixel i itself. The nearest pixels Ni can be defined in various ways, for example, as the 4, 8, 12, or 16 pixels closest to the target pixel i. Clearly, other definitions are possible. cjP denotes the intensity level of pixel j in the processed digital art image selected from a number of intensity levels after processing. cj denotes the intensity level of pixel j in the original digital art image. The weight wij (or filter kernel) is defined by a Gaussian filter / distribution.

[0113]

number

[0114] where σ s is the standard deviation of the Gaussian distribution and xi is the spatial location of target pixel i.

[0115] The cjP of N pixels is obtained by an optimization problem of reducing the cost function E. There are many optimization algorithms that can optimize this problem. process Optimized dithering process This will be called.

[0116] In a preferred embodiment, dithering process Multi-dithering process and optimized dithering process Or, optimized dithering process Such optimization-based adaptive dithering processcontains a cost function, where the weights or filter kernels for "blending" the surrounding pixels depend on the content of these surrounding pixels. The cost function weights or filter kernels may depend on the presence of edges and / or pixel characteristics of the surrounding pixels in the (original) digital art image. process Here are some examples:

[0117] In one embodiment of the edge detection process, the cost function depends on the edges and / or intensity level differences of each surrounding pixel. This can be achieved by redefining the weights in the cost function E in equation (1) by the following weights:

[0118]

number

[0119] Substitute wij in equation (1). σr is the standard deviation of the Gaussian distribution of the intensity differences, i.e., it defines how much weight a particular intensity difference should be considered. This weighting function reduces the importance of pixels beyond the edge, or with larger intensity differences, relative to the target pixel in the cost function, so that the optimization problem only considers pixels to the right of the edge.

[0120] In one embodiment of a cost function that depends on features and edges, the cost function is:

[0121]

number

[0122] The importance value ti depends on the feature. An example equation for the importance value ti is:

[0123]

number

[0124] si is a pixel feature determined based on a known feature model. An example of such a feature model is described in Non-Patent Document 1, which is incorporated herein by reference for purposes of calculating feature si. The feature specifies the importance of a pixel to human perception. For example, certain pixels or regions of an image (feature pixels / regions) are considered to be of the highest importance to human perception. These feature pixels / regions are given higher importance in the optimization, so that the optimization error is shifted to less important regions of the processed digital art image. The parameter λ is non-zero, and ti is non-zero. Here, λ is set to 0.1. However, si can also be used as ti.

[0125] In one embodiment of a feature-dependent cost function, the cost function defined in (4) can also be used in combination with other weighting functions (e.g., defined in equation (2)), e.g., as defined in equation (2).

[0126] Feature and / or edge dependent dithering process Adaptive dithering such as process As mentioned above, multi-dithering process This is yet another example.

[0127] Image processing of the digital art image to obtain a processed digital art image may include a quality check to determine whether the processed digital art image sufficiently corresponds to the (original) digital art image. In a preferred embodiment, this quality check may include taking a photograph of the processed digital art image on an auxiliary electronic paper display with the same characteristics as electronic paper display 21. Because photographic errors are similar to those of the human eye, comparing the (original) digital art image with a photograph taken from the auxiliary electronic paper display displaying the processed digital art image provides a very good quality check of the processed digital art image. Based on this quality check, server 1 may determine whether the processed digital art image needs further improvement. For example, semi-automatic image processing may automatically perform image processing to obtain the processed digital art image. If the quality of the processed digital art image is sufficient, the processed digital art image may be added to database 11 or transferred to the user's digital art frame 2. If the quality of the processed digital art image is not sufficient, human image processing may be required (semi-automatic), or further iterations of image processing may be possible (automatic). A quality check configuration 15 may be included for each type of digital art frame 2, for each type of electronic paper display 21 used with various types of digital art frames 2, or for different auxiliary electronic paper displays. Each auxiliary electronic paper display of the quality check configuration 15 preferably has the same display characteristics as the various types of electronic paper displays 21. Therefore, each auxiliary electronic paper display is preferably different from each other. As described above, a different processed digital art image is generated for each type of electronic paper display. The various processed digital art images are preferably displayed on various auxiliary electronic paper displays with display characteristics for which the processed digital art images are optimized. A camera is configured to capture the various auxiliary electronic paper displays.This can be achieved by using multiple cameras, each capturing a different auxiliary e-paper display, or by using a movable camera, which allows the quality of the processed digital art image to be checked for each type of digital art frame 2.

[0128] The steps of processing the digital art images are preferably performed (in part or in whole) on the server 1. However, it is also possible to perform the processing of the digital art images by human image processing in a computer-aided image processing program and upload the processed digital art images to the server 1 / database 11.

[0129] The method includes the step S2 of transferring the processed digital art image to the digital art frame 2. As detailed above, the processed digital art image is preferably transferred directly to the digital art frame 2.

[0130] The method includes a step S3 of displaying the transferred (processed) digital art image on the digital art frame 2.

[0131] Although the present invention has been described only in terms of gray levels, it is equally applicable to electronic paper displays 21 that also display color, in which case the above processing may be performed separately or jointly for each color space in the three-dimensional color space.

[0132] It should be understood that the present invention is not limited to the above-described embodiments, and modifications can be made without departing from the scope of the claims.

Claims

1. 1. A method for displaying a digital art image, comprising: processing (S1) a plurality of digital art images, wherein processing each digital art image of the plurality of digital art images includes reducing a number of intensity levels of the digital art image to a number of processed intensity levels, and obtaining a respective processed digital art image of the plurality of processed digital art images with the number of processed intensity levels, wherein the number of processed intensity levels is at least four, and wherein processing each of the plurality of digital art images to obtain the respective processed digital art image of the plurality of processed digital art images includes a dithering process; storing the plurality of processed digital art images in a database (11) of the server (1); selecting, on the server (1) via an intermediary device (3), from among the plurality of processed digital art images displayed on a digital art frame (2), wherein, when selecting the processed digital art image to be displayed, a plurality of selected digital art images are displayed on the intermediary device (3), and each selected digital art image is one of the plurality of processed digital art images; a step (S2) of transferring the processed digital art image selected by the intermediary device (3) to the digital art frame (2), the digital art frame (2) including mounting means (22) for mounting the digital art frame (2) on a wall, the digital art frame (2) including a battery (24) configured to provide power for operating the digital art frame (2); and (S3) displaying the processed digital art image on an electronic paper display (21) of the digital art frame (2).

2. 2. The method of claim 1, wherein a first digital art image is processed with a first dithering process to obtain a first processed digital art image, and a second digital art image is processed with a second dithering process to obtain a second processed digital art image, the first dithering process being different from the second dithering process, and the first or second processed digital art image is transferred to the digital art frame (2) and displayed on the electronic paper display of the digital art frame (2).

3. 2. The method of claim 1, wherein the dithering of the digital art image comprises multi-dithering of the digital art image, the multi-dithering of the digital art image applying different dithering processes to different regions of the digital art image.

4. 4. The method of claim 3, wherein the multi-dithering process includes selecting at least a first region and a second region as the various regions, and applying a first dithering process to the first region and a second dithering process to the second region, wherein the first dithering process and the second dithering process are different.

5. 5. The method of claim 4, wherein the first dithering process and the second dithering process are different dithering processes.

6. 6. The method of claim 5, wherein the first dithering process is an ordered dithering process and the second dithering process is an error diffusion dithering process.

7. 5. A method according to claim 4, characterized in that the selection of the different regions and / or the selection of the different dithering processes for each of the different regions is determined by the server (1).

8. 4. The method of claim 3, wherein the multi-dithering process includes an adaptive dithering filter, with a filtering kernel that is different in different regions of the digital art image.

9. 9. The method of claim 8, wherein the filtering kernel depends on a region of application of the filtering kernel, and the filtering kernel depends on intensity differences of pixels in the region of application of the filtering kernel of the digital art image.

10. 2. The method according to claim 1, wherein the server (1) is accessible by a plurality of users, and each user accesses a user area of ​​the server (1), thereby registering the type of the digital art frame (2) belonging to each of the plurality of users in the user area of ​​the server (1).

11. 2. The method of claim 1, wherein the wireless communication interface (23) of the digital art frame (2) configured to communicate with the server (1) and / or receive the processed digital art image selected by the intermediary device (3) includes a switch for powering on the wireless communication interface (23), the switch being a switch of the digital art frame (2) operated by user input from a user input means (28) of the digital art frame (2).

12. The method of claim 1, wherein multiple processed digital art images are delivered to multiple digital art frames according to the detected orientation of the digital art frames.

13. 2. The method according to claim 1, wherein the mounting means (22) of the digital art frame (2) comprises a frame portion fixed to the digital art frame and a wall-fixing portion fixed to the wall, and the digital art frame (2) can be removably fixed to the wall-fixing portion by the frame portion in two directions, the two directions having a difference of 90°.

14. The first digital art frame (2) as the digital art frame (2) comprises a first electronic paper display (21) as the electronic paper display (21) having a first characteristic, the first characteristic defining the number of pixels, size and / or pixel density of the first electronic paper display (21), the second digital art frame (2) comprises a second electronic paper display (21) having a second characteristic different from the first characteristic, the second characteristic defining the number of pixels, size and / or pixel density of the second electronic paper display (21), and the digital art image 2. The method of claim 1, wherein processing includes a first processing of the digital art image to obtain a first-processed digital art image and a second processing of the digital art image to obtain a second-processed digital art image, the first processing and the second processing respectively including reducing a number of intensity levels of the digital art image and dithering the digital art image, the first-processed digital art image being transferred to the first digital art frame for display, and the second-processed digital art image being transferred to the second digital art frame for display.

15. The processing of the digital art image includes: displaying the processed digital art image on an auxiliary electronic paper display identical to the electronic paper display (21) of the digital art frame (2); taking a photograph of the processed digital art image displayed on the auxiliary electronic paper display; comparing the photograph with the original digital art image to obtain a comparison result; and using the comparison to determine a quality of the processed digital art image.

16. A system for displaying digital art images includes a server (1), an intermediary device (3), and a digital art frame (2), wherein the digital art frame (2) includes an electronic paper display (21) with a number of intensity levels, and the digital art frame (2) includes mounting means (22) for mounting the digital art frame (2) on a wall, the server (1) includes image processing means (13) configured to process the digital art images into processed digital art images, wherein processing (S1) each of the digital art images of a plurality of digital art images includes reducing the number of intensity levels of the digital art image to a number of processed intensity levels and obtaining a processed digital art image with the number of processed intensity levels, wherein processing each of the digital art images includes a dithering process, and the server (1) stores the plurality of processed digital art images. the number of intensity levels of the processed digital art image is the same as the number of intensity levels of the electronic paper display (21), the number of intensity levels of the processed digital art image being at least four; the intermediary device (3) is configured to select from among the processed digital art images to be displayed on the digital art frame (2) at the server (1); the intermediary device (3) is configured so that, when selecting the processed digital art image to be displayed, multiple selected digital art images are displayed on the intermediary device (3), each selected digital art image being one of the multiple processed digital art images; and the system is configured to transfer the selected processed digital art image to the digital art frame (2) and display the transferred processed digital art image on the electronic paper display (21) of the digital art frame (2).

Images