Display device and image processing method

Abstract

A display device and an image processing method, the image processing method comprising the following steps: receiving an original image signal, wherein the original image signal comprises a plurality of original pixel values; identifying at least one object edge in the original image signal to generate a contour image signal; and correcting the original image signal according to the contour image signal to generate an enhanced image signal with a clearer contour.

Description

Technical Field

[0001] The present disclosure relates to a display device and an image processing method, and more particularly to a technology for presenting a picture according to an image signal. Background Art

[0002] In today's market of various consumer electronic products, "reflective display devices" are widely used to make display screens, such as electronic paper display devices. Reflective display devices mainly use incident light to illuminate the display medium layer to achieve the purpose of display, thus saving power. However, with the improvement of imaging technology, the resolution of the picture is also getting higher and higher. With the improvement of the picture fineness, how to improve the image processing method so that the reflective display device will not have jagged or image damage when displaying high-resolution pictures has become a major research topic at present. Summary of the invention

[0003] One aspect of the present disclosure is an image processing method, comprising the following steps: receiving an original image signal, wherein the original image signal comprises a plurality of original pixel values; identifying at least one object edge in the original image signal to generate a contour image signal; and correcting the original image signal according to the contour image signal to generate an enhanced image signal.

[0004] In one embodiment, a method for generating a contour image signal includes: comparing adjacent original pixel values ​​to obtain a plurality of difference values; and generating a contour image signal according to the difference values, wherein the contour image signal includes a plurality of contour pixel values.

[0005] In one embodiment, the method for generating a contour image signal further includes: retaining the original pixel values ​​in the original image signal whose difference values ​​are greater than a threshold value, and using the retained original pixel values ​​as the contour pixel values.

[0006] In one embodiment, the method for generating an enhanced image signal includes: reducing the original pixel values ​​corresponding to the contour image signal in the original image signal by a correction ratio.

[0007] In one embodiment, the image processing method further comprises: before correcting the original image signal according to the contour image signal, performing a color enhancement process on the original image signal.

[0008] In one embodiment, the color enhancement process includes: adjusting the saturation, contrast or brightness of the original image signal.

[0009] In one embodiment, the image processing method further includes: generating a control voltage according to the enhanced image signal to adjust the positions of the plurality of electrophoretic particles.

[0010] Another aspect of the present disclosure is a display device, comprising a display circuit and a processor. The display circuit comprises a plurality of pixel units. The processor is electrically connected to the display circuit and is used to receive an original image signal. The processor is used to identify an edge of at least one object in the original image signal to generate a contour image signal, and the processor is also used to correct the original image signal according to the contour image signal to generate an enhanced image signal.

[0011] In one embodiment, the processor compares a plurality of original pixel values ​​in the original image signal to obtain a plurality of difference values, and the processor is further configured to generate a contour image signal according to the difference values, wherein the contour image signal includes a plurality of contour pixel values.

[0012] In one embodiment, the processor is used to retain the original pixel values ​​in the original image signal whose difference values ​​are greater than a threshold value, and use the retained original pixel values ​​as the contour pixel values.

[0013] In one embodiment, the processor reduces the original pixel values ​​corresponding to the contour image signals in the original image signal by a correction ratio.

[0014] In one embodiment, before correcting the original image signal according to the contour image signal, the processor performs a color enhancement process on the original image signal.

[0015] In one embodiment, in the color enhancement process, the processor is used to adjust the saturation, contrast or brightness of the original image signal.

[0016] In one embodiment, the pixel units further include a plurality of electrophoretic particles, and the processor is used to generate a control voltage according to the enhanced image signal, and the control voltage is used to adjust the positions of the electrophoretic particles.

[0017] In one embodiment, the display device further comprises a color filter layer, wherein the color filter layer comprises a plurality of filter units, wherein the filter units correspond to the pixel units.

[0018] Another aspect of the present disclosure is an image processing method, comprising the following steps: receiving an original image signal, wherein the original image signal comprises a plurality of original pixel values; identifying at least one object edge in the original image signal to generate a contour image signal; and using the contour image signal to enhance at least one object edge in the original image signal to generate an enhanced image signal.

[0019] By capturing the contour image signal and then enhancing the original image signal according to the contour image signal, the image displayed by the display device can be made clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1Ais a schematic diagram of a display device according to some embodiments of the present disclosure;

[0021] Figure 1B Schematic diagram of an original image frame and a contour image frame according to some embodiments of the present disclosure;

[0022] Figure 2 is a flow chart of an image processing method according to some embodiments of the present disclosure;

[0023] Figures 3A to 3C Schematic diagram of an original image frame, a contour image frame and an enhanced image frame according to some embodiments of the present disclosure;

[0024] Figures 4A to 4C Schematic diagram of an original image frame, a contour image frame and an enhanced image frame according to some embodiments of the present disclosure;

[0025] Figure 5 A schematic diagram of correction effects of image processing methods and other methods according to some embodiments of the present disclosure;

[0026] Figure 6 Schematic diagram of correction effects of image processing methods and other methods according to some embodiments of the present disclosure.

[0027]

Explanation of symbols

[0028] 100: Display device

[0029] 110: Display circuit

[0030] 111: transistor array layer

[0031] 112: Electronic ink layer

[0032] 112a: Electrophoretic particles

[0033] 112b: Electrophoretic particles

[0034] 113: Color filter layer

[0035] 113a: Filter unit

[0036] 120: Processor

[0037] 130: Touch panel

[0038] 140: Front light module

[0039] PX: Pixel unit

[0040] A100: Original image screen

[0041] A1-A9: Pixels

[0042] B100: Silhouette image screen

[0043] B1-B9: Pixels

[0044] 510-540: Image

[0045] 610-640: Image

[0046] S201-S206: Steps DETAILED DESCRIPTION

[0047] The following will disclose multiple embodiments of the present invention with the accompanying drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not necessary. In addition, in order to simplify the drawings, some conventional structures and elements will be depicted in a simple schematic manner in the drawings.

[0048] In this document, when an element is referred to as "connected" or "coupled", it may refer to "electrically connected" or "electrically coupled". "Connected" or "coupled" may also be used to indicate that two or more elements cooperate or interact with each other. In addition, although the terms "first", "second", etc. are used in this document to describe different elements, the terms are only used to distinguish between elements or operations described by the same technical terms. Unless the context clearly indicates otherwise, the terms do not specifically refer to or imply an order or sequence, nor are they used to limit the present invention.

[0049] The present disclosure relates to a display device and an image processing method. Figure 1A FIG. 1 is a schematic diagram of a display device 100 according to some embodiments of the present disclosure. The display device 100 at least includes a display circuit 110 and a processor 120. In one embodiment, the display device 100 is a reflective display, such as electronic paper, but the present disclosure is not limited to electronic paper. In other embodiments, the image processing method is applied to other types of displays.

[0050] like Figure 1AAs shown, the display circuit 110 further includes a transistor array layer 111, an electronic ink layer 112, and a color filter layer 113. The transistor array layer 111 (e.g., thin film transistor array, TFT array) can form an electric field according to a control voltage to adjust the positions of a plurality of electrophoretic particles 112a, 112b in the electronic ink layer 112, thereby presenting different grayscale colors. The electronic ink layer 112 of the present disclosure is composed of electrophoretic particles 112a, 112b respectively encapsulated in a plurality of microcapsules or microcups to serve as a plurality of pixel units PX, but the electronic ink layer 112 of the present disclosure is not limited to the above structure.

[0051] As mentioned above, the color filter layer 113 (e.g., color filter array) includes a plurality of filter units 113a, such as red, green, and blue filter units, and the position of each filter unit 113a corresponds to one or more pixel units PX. The filter units 113a are arranged in a specific manner so that the grayscale image displayed by the electronic ink layer 112 can form a color image through the color filter layer 113.

[0052] In some other embodiments, the display device 100 may further include a touch panel 130 and a front light module 140 . The touch panel 130 is used to detect the touch action of the user, and the front light module 140 is used to provide a front light source.

[0053] The processor 120 is electrically connected to the display circuit 110 and can be integrated with the display circuit 110. The processor 120 is used to receive an original image signal (e.g., a photo of a chameleon, or an image showing an article). The processor 120 can generate a control voltage according to the original image signal to generate an electric field through the transistor array layer 111 to adjust the positions of the electrophoretic particles 112a and 112b, thereby causing the display circuit 110 to display a corresponding image. However, when the original image signal is used to present tiny objects (e.g., small fonts or small objects), there may be a problem of insufficient clarity, so the present disclosure will first calibrate the original image signal to improve the image quality.

[0054] In some embodiments, when the processor 120 receives the original image signal, the processor 120 will identify the pixel values ​​used to present one or more object edges in the original image signal to generate a contour image signal. By extracting the contour image signal and correcting the original image signal accordingly, the display device 100 will be able to highlight the object edges in the picture, making the picture clearer. In other words, the processor 120 can use the contour image signal to enhance the object edges in the original image signal to generate an enhanced image signal.

[0055] Figure 1B The original image signal corresponds to an original image frame A100 and a contour frame B100 (described later). Figure 2 FIG. 1 is a schematic diagram of an image processing method according to some embodiments of the present disclosure. In step S201, the processor 120 receives an original image signal, wherein the original image signal includes a plurality of original pixel values. Figure 1B As shown, the original picture A is composed of a plurality of pixels A1 - A9 , and the original pixel value may be a grayscale value or a brightness value of each pixel.

[0056] In step S202, the processor 120 compares each original pixel value with the adjacent original pixel values ​​to obtain the difference value of each original pixel value. For example, for pixel A5, the processor 120 can compare the difference between pixel A5 and pixels A1-A4 and A6-A9 respectively, and average or take the maximum value of the comparison results as the "difference value of pixel A5".

[0057] In step S203, the processor 120 selects the original pixel values ​​whose difference values ​​are greater than the threshold value. Specifically, the processor 120 determines whether the difference value is greater than a threshold value (eg, the difference is greater than 60%), and the original pixel values ​​corresponding to the difference values ​​greater than the threshold value are set as contour pixel values.

[0058] In step S204, the processor 120 retains those original pixel values ​​in the original image signal that are greater than the threshold value (i.e., the aforementioned set contour pixel values), and deletes other original pixel values ​​that have not been filtered out to form a contour image signal. In other words, the processor 120 can generate a contour image signal based on the original pixel values ​​filtered out by the difference value. The contour image signal includes the contour pixel values.

[0059] The contour image signal corresponds to the contour picture B100. Figure 1B As shown in the figure, if the difference between the original pixels A5 and A8 and the surrounding pixels is greater than the threshold value, it means that the original pixels A5 and A8 are used to present the outline or edge of an object, so the processor will only retain the original pixels A5 and A8 and delete the other original pixels. Similarly, if the difference between the original pixel A7 and the surrounding pixels is less than the threshold value, it means that the original pixel A7 is not used to present the outline or edge of an object, so it will be deleted. The result after screening (the original pixel values ​​that are retained, i.e. Figure 1B The contour image B100 shown is used as the contour image signal. There are many algorithms for extracting the contour of an object from an image, and since those skilled in the art can understand the principles, they will not be described in detail here.

[0060] In step S205, after obtaining the contour image signals, the processor 120 reduces the original pixel values ​​corresponding to the contour image signals in the original image signal according to the contour image signals. In image processing, "contours" are usually recorded as light-colored or white pixels. The processor 120 can subtract the original pixel values ​​corresponding to the contour image signals in the original image signal to generate an enhanced image signal (i.e., Figure 1B In some embodiments, the processor may reduce the original pixel values ​​corresponding to the contour image signals in the original image signal according to a pre-set correction ratio. For example, the grayscale value or brightness value of the original pixels A5 and A8 corresponding to the contour pixels B5 and B8 is reduced by 60%. The correction ratio can be adjusted according to the display effect requirements. In addition, in other embodiments, the processor 120 may also set different correction ratios for different parts of the original image signal (i.e., different areas of the original image screen).

[0061] In step S206 , after the processor 120 obtains the enhanced image signal, it will generate a control voltage according to the enhanced image signal and drive the display circuit 110 accordingly to adjust the positions of the electrophoretic particles 112 a and 112 b to present an enhanced image.

[0062] In some embodiments, before the processor 120 corrects the original image signal according to the contour image signal, the processor 120 may also perform a color enhancement process on the original image signal. In the color enhancement process, the processor 120 is used to adjust the saturation, contrast or brightness of the original signal. Although the color enhancement process can improve the color quality of the picture, it may also affect the clarity of the picture. The present disclosure may first perform color enhancement on the original image signal, and then correct the original image signal after color enhancement according to the contour image signal, thereby taking into account both color quality and picture clarity.

[0063] Figures 3A to 3C FIG. 1 is a schematic diagram of a “text image” processed by an image processing method according to some embodiments of the present disclosure, wherein Figure 3A For the original image, Figure 3B For the outline image screen, Figure 3C This is the result of correcting the original image according to the contour image (enhanced image). It can be clearly seen from the attached figure that the corrected image is obviously sharper and clearer. Figure 3B The outline image shown has been converted from inverted color to black to present the outline. In other words, according to the outline image signal generated by different capture methods, the "outline" may be presented in dark color or light color.

[0064] Similarly, Figures 4A to 4C is a schematic diagram of a “chameleon photo” processed by an image processing method according to some embodiments of the present disclosure, Figure 4A For the original image, Figure 4B For the outline image screen, Figure 4C This is the result of correcting the original image based on the contour image. The corrected image is obviously sharper and clearer.

[0065] Figure 5 The image processing method of the present disclosure is compared with other edge enhancement algorithms. Image 510 is the original image, and images 520 and 530 are images presented by different edge enhancement algorithms. Image 540 is an enhanced image presented by the image processing method of some embodiments of the present disclosure. Comparing the accompanying drawings, it can be seen that the outline of image 540 is clearer than that of other images 510 to 530, and no jagged edges are generated.

[0066] Similarly, Figure 6 This is a comparison chart of the effects of the image processing method of the present disclosure and other edge enhancement algorithms. Image 610 is the original image screen, and images 620 and 630 are the screens presented by different edge enhancement algorithms. Image 640 is the enhanced image screen presented by the image processing method of some embodiments of the present disclosure. Comparing the attached figures, it can be seen that the contour of image 640 is clearer than that of other images 610 to 630, and the "q" in the screen is the most complete, without the distortion phenomenon of contour breakage.

[0067] The various elements, method steps or technical features in the aforementioned embodiments may be combined with each other and are not limited to the order of textual description or the order of presentation of the drawings in the present disclosure.

[0068] Although the present disclosure has been disclosed in the above implementation mode, it is not intended to limit the present disclosure. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be based on the scope defined by the attached claims.

Claims

1. An image processing method, characterized in that: Include: Receiving an original image signal, wherein the original image signal comprises a plurality of original pixel values; Comparing the adjacent original pixel values ​​to obtain a plurality of difference values; Generating a contour image signal according to the difference values, wherein the contour image signal comprises a plurality of contour pixel values; Performing a color enhancement process on the original image signal; and The original pixel values ​​corresponding to the contour image signal in the original image signal after color enhancement are reduced at a correction ratio to generate an enhanced image signal.

2. The image processing method according to claim 1, wherein: The method for generating the contour image signal further comprises: The original pixel values ​​of the original image signal whose difference values ​​are greater than a threshold value are retained, and the retained original pixel values ​​are used as the contour pixel values.

3. The image processing method according to claim 1, wherein: The color enhancement program includes: The saturation, contrast or brightness of the original image signal is adjusted.

4. The image processing method according to claim 1, wherein: Also includes: A control voltage is generated according to the enhanced image signal to adjust the positions of a plurality of electrophoretic particles.

5. A display device, characterized in that: Include: A display circuit comprising a plurality of pixel units; and a processor, electrically connected to the display circuit, and used for receiving an original image signal, wherein the processor is used for identifying an edge of an object in the original image signal, and for comparing a plurality of original pixel values ​​in the original image signal to obtain a plurality of difference values, and the processor is further used for generating a contour image signal according to the difference values, wherein the contour image signal includes a plurality of contour pixel values; The processor is used to perform a color enhancement process on the original image signal; The processor is further used to reduce the original pixel values ​​corresponding to the contour image signals in the original image signal after color enhancement by a correction ratio to generate an enhanced image signal.

6. The display device according to claim 5, characterized in that The processor is used for retaining the original pixel values ​​whose difference values ​​in the original image signal are greater than a threshold value, and using the retained original pixel values ​​as the contour pixel values.

7. The display device according to claim 5, characterized in that In the color enhancement process, the processor is used to adjust the saturation, contrast or brightness of the original image signal.

8. The display device according to claim 5, characterized in that The pixel units further include a plurality of electrophoretic particles, and the processor is used to generate a control voltage according to the enhanced image signal, and the control voltage is used to adjust the positions of the electrophoretic particles.

9. The display device according to claim 8, wherein: Also includes: A color filter layer includes a plurality of filter units, wherein the filter units correspond to the pixel units.

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