Image signal processing device, image signal processing method, computer-readable storage medium

Abstract

The processing device (200) includes a basic component extraction unit (221), a basic component adjustment unit (222), a detail component extraction unit (223), a relative emphasis unit (230), and a synthesis unit (240). The basic component extraction unit (221) generates an original basic component signal based on an image signal. The basic component adjustment unit (222) performs weighted average processing to generate a first basic component signal. The detail component extraction unit (223) generates a first detail component signal based on the image signal. The relative emphasis unit (230) performs signal processing to emphasize the first detail component signal relative to the first basic component signal to output a second basic component signal and a second detail component signal. The synthesis unit (240) synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal.

Description

Technical Field

[0001] The disclosure of this specification relates to an image signal processing device, an image signal processing method, and a program. Background Art

[0002] In recent years, the use of an endoscope system that can detect and treat lesions at an early stage has been gradually expanding, mainly in the medical field. Among the lesions that should be detected during endoscopy, there are various types of lesions. For example, there are also lesions with poor visual recognition such as inflammation and unevenness on the gastric mucosa. In order to detect such lesions with poor visual recognition without omission, a technique for improving the visual recognition of lesions is sought in the field of endoscope systems.

[0003] For example, Patent Document 1 describes a technique related to such a technical problem. Patent Document 1 describes the following technique: dividing an image signal into a base component and a detail component, performing gray-level compression processing on the base component, and synthesizing the detail component with the base component that has undergone gray-level compression processing to generate an endoscope image. In addition, the detail component includes a contrast component, and the contrast component includes information such as the outline and texture of an object.

[0004] According to the technique described in Patent Document 1, an endoscope image with good visual recognition can be obtained, and lesions can be detected more easily. Also, in the technique described in Patent Document 1, the visual recognition of the endoscope image can be improved while suppressing the change in hue. Therefore, the diagnosis of lesions can be performed based on established diagnostics as in the past.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: International Publication No. 2017 / 203866 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In the technique described in Patent Document 1, the base component is gray-level compressed, thereby emphasizing the detail component relative to the base component. When this relative emphasis is too strong, the impression of the obtained endoscope image may be very different from that of a conventional endoscope image. Therefore, although the visual recognition is improved and it is easy to detect lesions, on the other hand, for example, it may occur that a degree stronger than the original degree of gastric mucosal inflammation is diagnosed. Thus, a technique for adjusting the impression of an image by adjusting the degree of relative emphasis is sought.

[0010] Based on the above actual situation, an object of one aspect of the present invention is to provide an image signal processing technology that improves visual recognition with respect to conventional images.

[0011] In addition, an object of other aspects of the present invention is to provide an image signal processing technology capable of adjusting the difference in impression from conventional images.

[0012] Solution to the problem

[0013] The image signal processing apparatus according to one aspect of the present invention includes: a basic component extraction unit that extracts a basic component from an image signal to generate an original basic component signal; a basic component adjustment unit that performs a weighted average process on the image signal and the original basic component signal to generate a first basic component signal; a detail component extraction unit that extracts a detail component from the image signal based on the first basic component signal to generate a first detail component signal; a relative emphasis unit that performs signal processing for emphasizing the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal; a synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; and a storage unit that stores a plurality of control parameters related to the similarity between the image signal and the first basic component signal. The basic component adjustment unit acquires the selected control parameter among the plurality of control parameters stored in the storage unit, and performs the weighted average process using a weight coefficient determined according to the selected control parameter, thereby generating the first basic component signal.

[0014] The image signal processing apparatus according to another aspect of the present invention includes: a segmentation unit that segments an image signal into a first basic component signal and a first detail component signal according to a control parameter and outputs them; a relative emphasis unit that performs signal processing for emphasizing the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal; a synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; and a storage unit that stores a plurality of the control parameters related to the similarity between the image signal and the first basic component signal. The segmentation unit segments the image signal into a first basic component signal and a first detail component signal according to the selected control parameter among the plurality of control parameters stored in the storage unit and outputs them.

[0015] An image signal processing apparatus according to another aspect of the present invention includes: a basic component extraction unit that extracts a basic component from an image signal to generate an original basic component signal; a basic component adjustment unit that performs a weighted average process on the image signal and the original basic component signal to generate a first basic component signal; a detail component extraction unit that extracts a detail component from the image signal based on the first basic component signal to generate a first detail component signal; a relative emphasis unit that performs signal processing for emphasizing the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal; a synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; and a storage unit that stores a plurality of control parameters related to the similarity between the image signal and the first basic component signal. The basic component adjustment unit acquires the selected control parameter among the plurality of control parameters stored in the storage unit, and performs the weighted average process using a weight coefficient determined according to the selected control parameter, thereby generating the first basic component signal. The relative emphasis unit includes a gray-level compression unit that performs gray-level compression processing on any one of the image signal, the original basic component signal, and the first basic component signal, thereby generating the second basic component signal.

[0016] An image signal processing method according to one aspect of the present invention is as follows: extracting a basic component from an image signal to generate an original basic component signal, performing a weighted average process on the image signal and the original basic component signal using a weight coefficient determined according to the selected control parameter, thereby generating a first basic component signal, extracting a detail component from the image signal based on the image signal and the first basic component signal to generate a first detail component signal, performing signal processing for emphasizing the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal, and synthesizing the second basic component signal and the second detail component signal to generate a synthesized image signal.

[0017] A computer-readable storage medium according to one aspect of the present invention stores a program that causes a computer to perform the following processes: extracting a basic component from an image signal to generate an original basic component signal, performing a weighted average process on the image signal and the original basic component signal using a weight coefficient determined according to a selected control parameter, thereby generating a first basic component signal, extracting a detail component from the image signal based on the image signal and the first basic component signal to generate a first detail component signal, performing a signal process on at least one of the first basic component signal and the first detail component signal to emphasize the first detail component signal with respect to the first basic component signal, thereby outputting a second basic component signal and a second detail component signal, and synthesizing the second basic component signal and the second detail component signal, thereby generating a synthesized image signal.

[0018] Effects of the Invention

[0019] According to the above aspect, visual recognition can be improved with respect to a conventional image. In addition, according to other aspects, the difference in impression from a conventional image can be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a diagram illustrating the configuration of an endoscope system 1 according to the first embodiment.

[0021] Figure 2 FIG. is a flowchart of image signal processing according to the first embodiment.

[0022] Figure 3 FIG. is a flowchart of signal segmentation processing according to the first embodiment.

[0023] Figure 4 FIG. is a diagram showing line profiles of a basic component signal in cases where Alpha values are 0, 0.5, and 1, respectively.

[0024] Figure 5 FIG. is a diagram showing line profiles of the ratio of a detail component signal to a basic component signal in cases where Alpha values are 0, 0.5, and 1, respectively.

[0025] Figure 6 FIG. is a diagram illustrating the configuration of an endoscope system 2 according to the second embodiment.

[0026] Figure 7 FIG. is a diagram illustrating the configuration of an endoscope system 3 according to the third embodiment.

[0027] Figure 8 FIG. is a flowchart of signal segmentation processing according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] [First Embodiment]

[0029] Figure 1 This is a diagram illustrating the structure of the endoscope system 1 according to the present embodiment. The endoscope system 1 is, for example, a medical endoscope system, and as Figure 1 shown, includes an endoscope 100, a processing device 200, and a display device 300.

[0030] The endoscope 100 is, for example, a flexible endoscope, and includes an insertion portion inserted into a subject, an operation portion operated by a surgical operator, a general-purpose flexible cable portion extending from the operation portion, and a connector portion provided at the end of the general-purpose flexible cable portion and connected to the processing device 200. The endoscope 100 outputs a captured image signal generated by capturing an image of the subject in a state where the insertion portion is inserted into the body cavity of the subject to the processing device 200.

[0031] The endoscope 100 includes an optical system 110, an imaging element 120, an optical waveguide 130, and an illumination lens 140. In addition, the optical system 110, the imaging element 120, and the illumination lens 140 are provided in the insertion portion, and the optical waveguide 130 is disposed from the connector portion through the general-purpose flexible cable portion and the operation portion to the insertion portion.

[0032] The optical system 110 includes one or more lenses, and forms an optical image of the subject on the light-receiving portion 121 of the imaging element 120 by converging light from the subject. The optical system 110 may also have a moving structure that moves at least a part of the one or more lenses included in the optical system 110 in the optical axis direction. The optical system 110 may also implement an optical zoom function for changing the projection magnification of the optical image and a focusing function for moving the focal position to focus on the subject through this moving structure.

[0033] The imaging element 120 is, for example, a two-dimensional image sensor such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging element 120 receives light from the subject on the light-receiving surface via the optical system 110, and converts the received light into an electrical signal, thereby generating a captured image signal of the subject. More specifically, the imaging element 120 includes a light-receiving portion 121 and a readout portion 122.

[0034] In the light-receiving unit 121, for example, a plurality of pixels each including a photodiode and a capacitor are two-dimensionally arranged. Each pixel may also include a color filter. The color filters arranged in the plurality of pixels are arranged, for example, in a Bayer array. Alternatively, a plurality of photodiodes may be stacked in the thickness direction at each pixel instead of the color filter. The readout unit 122 reads the electrical signals generated by photoelectric conversion from the plurality of pixels and outputs them as imaging signals to the processing device 200.

[0035] The light guide 130 guides the illumination light provided from the light source unit 280 of the processing device 200 to the illumination lens 140. The illumination lens 140 irradiates the illumination light from the light guide 130 onto the subject.

[0036] The processing device 200 is a control device that controls the operation of the endoscope system 1 and is also referred to as an endoscope processor. The processing device 200 is an example of an image signal processing device. For example, the processing device 200 performs the signal processing described below on the imaging signals output from the endoscope 100, generates an image signal for display, and causes the display device 300 to display an image of the subject. In addition to this, the processing device 200 performs various processes such as dimming control.

[0037] The processing device 200 includes a dividing unit 220, a relative emphasis unit 230, and a synthesizing unit 240. The processing device 200 may also include an imaging signal processing unit 210, a display image generation unit 250, a control unit 260, an input unit 270, a light source unit 280, and a storage unit 290. In addition, each of the imaging signal processing unit 210, the dividing unit 220, the relative emphasis unit 230, the synthesizing unit 240, the display image generation unit 250, the control unit 260, and the light source unit 280 may be configured using a general-purpose processor such as a CPU, or may be configured using a dedicated processor such as an ASIC or an FPGA. That is, the processing device 200 includes an electrical circuitry for implementing the above-described constituent elements.

[0038] The processing device 200 divides the image signal generated by the imaging signal processing unit 210 into a base component signal and a detail component signal by the dividing unit 220. After that, the processing device 200 emphasizes the detail component signal relative to the base component signal by the relative emphasis unit 230, and then synthesizes these signals by the synthesizing unit 240 to generate a synthesized image signal. And the processing device 200 generates an image signal for display based on the synthesized image signal by the display image generation unit 250, thereby causing the display device 300 to display an endoscope image. The control unit 260 controls the overall operation of these actions. In addition, the control unit 260 reads out the control parameters used in the division process from the storage unit 290 in response to an input from the input unit 270 and provides them to the dividing unit 220. And the control unit 260 also controls the automatic dimming performed by the light source unit 280.

[0039] In addition, the basic component signal refers to the signal corresponding to the basic component in the image components included in the image signal. Additionally, the detail component signal refers to the signal corresponding to the detail component in the image components included in the image signal.

[0040] Furthermore, the basic component is a component with a relatively weak correlation with what the eyes perceive compared to the detail component. The basic component is also a low-frequency component with a low spatial frequency and is also an illumination light component depending on the illumination light irradiated onto the subject. On the other hand, the detail component is a component with a relatively strong correlation with what the eyes perceive compared to the basic component. The detail component is also a high-frequency component with a high spatial frequency and is also a reflectance component depending on the reflectance of the subject.

[0041] The imaging signal processing unit 210 performs prescribed processing on the imaging signal received from the endoscope 100, thereby generating an image signal. The prescribed processing includes, for example, denoising processing, analog-to-digital conversion processing, OB subtraction processing, WB correction processing, demosaicing processing, color matrix processing, etc. The imaging signal processing unit 210 outputs the generated image signal to the segmentation unit 220.

[0042] The segmentation unit 220 divides the image signal received from the imaging signal processing unit 210 into a basic component signal and a detail component signal according to control parameters. More specifically, the segmentation unit 220 includes a basic component extraction unit 221, a basic component adjustment unit 222, and a detail component extraction unit 223.

[0043] In addition, hereafter, the basic component signal output from the segmentation unit 220 will be specifically referred to as the first basic component signal, and the detail component signal output from the segmentation unit 220 will be specifically referred to as the first detail component signal. Additionally, the basic component signal output from the relative emphasis unit 230 will be specifically referred to as the second basic component signal, and the detail component signal output from the relative emphasis unit 230 will be specifically referred to as the second detail component signal.

[0044] The basic component extraction unit 221 extracts the basic component from the image signal received from the imaging signal processing unit 210 to generate a basic component signal and outputs it to the basic component adjustment unit 222. Hereafter, the basic component signal generated by the basic component extraction unit 221 will be specifically referred to as the original basic component signal. The method for extracting the basic component is not particularly limited. For example, edge-preserving smoothing filters such as a bilateral filter and an ε filter can be used.

[0045] The basic component adjustment unit 222 performs a weighted average process on the image signal and the original basic component signal, thereby generating a first basic component signal. More specifically, the basic component adjustment unit 222 obtains a control parameter for specifying the similarity between the image signal and the first basic component signal from the storage unit 290, and then performs a weighted average process using the weight coefficient determined according to the control parameter, thereby generating a first basic component signal. The generated first basic component signal is output to the detail component extraction unit 223 and the relative emphasis unit 230. In addition, the weighted average process performed by the basic component adjustment unit 222 is, for example, an Alpha blending process. The control parameter used in the basic component adjustment unit 222 is, for example, the Alpha value α used in the Alpha blending process. The weight coefficient determined according to the control parameter is, for example, the weight coefficient α for the image signal and the weight coefficient (1 - α) for the original basic component signal.

[0046] The weighted average process performed by the basic component adjustment unit 222 is a process of generating a signal between the original basic component signal and the image signal, and is essentially a process of making the original basic component signal approach the image signal input to the segmentation unit 220. It is possible to adjust how close it is to the image signal through the control parameter. That is, the weighted average process performed by the basic component adjustment unit 222 is a process of making the original basic component signal approach the image signal input to the segmentation unit 220 corresponding to the control parameter.

[0047] The detail component extraction unit 223 extracts a detail component from the image signal based on the first basic component signal to generate a first detail component signal. More specifically, the detail component extraction unit 223 divides the image signal by the first basic component signal, thereby generating a first detail component signal. The generated first detail component signal is output to the synthesis unit 240 via the relative emphasis unit 230.

[0048] The relative emphasis unit 230 performs a signal process of emphasizing the first detail component signal with respect to the first basic component signal output from the segmentation unit 220, thereby outputting a second basic component signal and a second detail component signal to the synthesis unit 240. More specifically, the relative emphasis unit 230 includes a gray level compression unit 231.

[0049] The gray level compression unit 231 performs a gray level compression process on the first basic component signal received from the basic component adjustment unit 222, thereby generating a second basic component signal and outputting it to the synthesis unit 240. The method of the gray level compression process performed by the gray level compression unit 231 is not particularly limited. As long as the dynamic range of the basic component signal is compressed at a specified ratio, the same method as the conventional gray level compression process for endoscopic images can also be used.

[0050] The grayscale compression unit 231 performs grayscale compression processing on the first basic component signal, thereby emphasizing the first detail component signal with respect to the first basic component signal. In addition, the second basic component signal output from the relative emphasis unit 230 is a signal obtained by performing grayscale compression processing on the first basic component signal. In contrast, the second detail component signal output from the relative emphasis unit 230 is the same as the first detail component signal.

[0051] The synthesizing unit 240 synthesizes the second basic component signal and the second detail component signal, thereby generating a synthesized image signal and outputting it to the display image generating unit 250. More specifically, the synthesizing unit 240 multiplies the second basic component signal and the second detail component signal, thereby generating a synthesized image signal.

[0052] The display image generating unit 250 generates an image signal for display based on the synthesized image signal received from the synthesizing unit 240 and outputs it to the display device 300.

[0053] The control unit 260 controls the overall operation of each unit within the processing device 200. In addition, the control unit 260 also outputs a control signal to a device outside the processing device 200 (e.g., the imaging element 120) to control the operation of the external device.

[0054] The input unit 270 is, for example, a switch, a touch panel, etc. provided in the processing device 200, and outputs a signal corresponding to the operation of the mouse operator to the control unit 260. In addition, the input unit 270 may also be a circuit that receives signals from input devices such as a keyboard, a mouse, a joystick, etc. connected to the processing device 200, and may also be a circuit that receives signals from input terminals such as a tablet computer.

[0055] The light source unit 280 outputs illumination light that irradiates the subject through the endoscope 100. More specifically, the light source unit 280 includes a light source 281, a light source driver 282, and a light source control unit 283.

[0056] The light source 281 is a light source that emits illumination light provided to the endoscope 100. The light source 281 is, for example, an LED light source, but is not limited to an LED light source, and may also be a light source such as a xenon lamp or a halogen lamp, or may also be a laser light source. In addition, the light source 281 may also include a plurality of LED light sources that respectively emit illumination light of different colors.

[0057] The light source driver 282 is a driver that drives the light source 281, and is, for example, an LED driver. The light source driver 282 drives the light source 281 according to an indicated value (e.g., a current value, a voltage value) from the light source control unit 283.

[0058] Based on the control signal from the control unit 260, the light source control unit 283 outputs an indication value to the light source driver 282, thereby controlling the illumination light quantity and illumination timing.

[0059] The storage unit 290 includes a ROM, a RAM, a hard disk, a flash memory, etc. The storage unit 290 stores various programs, parameters, and data obtained by the endoscope system 1. More specifically, the storage unit 290 at least includes a control parameter storage unit 291 for storing the control parameters used in the segmentation process of the segmentation unit 220.

[0060] The display device 300 is a device that displays an endoscope image using the image signal for display received from the processing device 200. The display device 300 is, for example, a liquid crystal display, an organic EL display, or the like.

[0061] In the endoscope system 1 configured as described above, the relative emphasis unit 230 of the processing device 200 emphasizes the detail component signal with respect to the base component signal, thereby enabling an endoscope image with higher visual recognition than in the past to be obtained. In addition, the segmentation unit 220 of the processing device 200 can adjust the similarity between the base component signal and the input signal, and thus can adjust the difference from the impression of the conventional endoscope image.

[0062] Therefore, according to the processing device 200, the visual recognition can be improved with respect to the conventional endoscope image, and the difference from the impression of the conventional endoscope image can be adjusted. In addition, according to the endoscope system 1 including the processing device 200, an endoscope image with improved visual recognition and adjusted impression can be displayed. Therefore, lesions can be reliably detected and the detected lesions can be accurately diagnosed.

[0063] Figure 2 It is a flowchart of the image signal processing according to the present embodiment. Figure 3 It is a flowchart of the signal segmentation processing according to the present embodiment. Figure 4 It is a diagram showing the line profiles of the base component signal in the cases where the Alpha values are 0, 0.5, and 1, respectively. Figure 5 It is a diagram showing the line profiles of the ratio of the detail component signal to the base component signal in the cases where the Alpha values are 0, 0.5, and 1, respectively. Next, refer to Figures 2 to 5 to specifically describe the image signal processing method performed by the processing device 200.

[0064] When the processing device 200 receives a captured image signal from the endoscope 100, it performs signal segmentation processing on the image signal generated based on the captured image signal (step S10). In addition, an example will be described later in which the processing device 200 is connected to the endoscope 100 and performs signal segmentation processing when receiving a captured image signal from the endoscope 100. However, the signal segmentation processing can also be performed, for example, when reading an image signal from the storage unit 290.

[0065] When Figure 3 When the signal segmentation processing shown starts, the processing device 200 first generates an original basic component signal (step S11). Here, for example, the basic component extraction unit 221 performs filtering processing on the image signal using an edge-preserving smoothing filter, thereby extracting the basic component from the image signal.

[0066] Next, the processing device 200 acquires control parameters to determine the weight coefficients (step S12). Here, for example, the basic component adjustment unit 222 first reads out the Alpha value α as a control parameter from the control parameter storage unit 291. In addition, the Alpha value α is a value from 0 to 1 and is determined according to a selection made in advance by the surgical operator. After that, the basic component adjustment unit 222 uses the Alpha value α to determine the weight coefficients. Specifically, the basic component adjustment unit 222 determines the weight coefficient for the image signal as α, for example, and determines the weight coefficient for the original basic component signal as (1 - α).

[0067] When the weight coefficients are determined, the processing device 200 performs weighted averaging on the image signal and the original basic component signal using the weight coefficients to generate a first basic component signal (step S13). Here, for example, the basic component adjustment unit 222 performs the following Alpha blending process to generate the first basic component signal. In this case, the closer the Alpha value α is to 1, the closer the first basic component signal is to the image signal.

[0068] First basic component signal = α × image signal + (1 - α) × original basic signal ··· (1)

[0069] In Figure 4 the line profiles of the first basic component signal when α = 0, α = 0.5, and α = 1 are shown. The horizontal axis represents the pixel position, and the vertical axis represents the luminance value of the first basic component signal at each pixel position.

[0070] It can be understood from Equation (1) that the first basic component signal when α = 1 is the image signal itself, and the first basic component signal when α = 0 is the original basic component signal itself. Thus, as Figure 4As shown, the first basic component signal is a signal from which high-frequency components have been removed through smoothing when α = 0, and is a signal with a large change in luminance value at each pixel position when α = 1. Additionally, when α = 0.5, the first basic component signal is a signal in between them.

[0071] When the first basic component signal is generated, the processing device 200 generates a first detail component signal (step S14), and ends the signal segmentation process. Here, for example, the detail component extraction unit 223 divides the image signal by the first basic component signal generated in step S13 to generate the first detail component signal.

[0072] In Figure 5 the line profiles of the ratio of the first detail component signal to the first basic component signal when α = 0, α = 0.5, and α = 1 are shown. The horizontal axis represents the pixel position, and the vertical axis represents the relative luminance value of the first detail component signal to the first basic component signal at each pixel position.

[0073] As Figure 5 shown, when α = 0, the relative luminance value is a value significantly deviated from 1. In contrast, when α = 1, the relative luminance value is fixed at 1. Additionally, when α = 0.5, the relative luminance value exhibits characteristics in between them.

[0074] When the signal segmentation process ends, the processing device 200 performs relative emphasis processing that emphasizes the first detail component signal with respect to the first basic component signal (step S20). Here, for example, the relative emphasis unit 230 outputs the first detail component signal as the second detail component signal, and the gray-level compression unit 231 outputs a second basic component signal generated by performing gray-level compression processing on the first basic component signal. In addition, in the gray-level compression processing, it is desirable to use the same parameters as those used in the gray-level compression processing of conventional endoscopic images.

[0075] Furthermore, the processing device 200 synthesizes the basic component signal and the detail component signal (step S30). Here, for example, the synthesis unit 240 performs synthesis by multiplying the second basic component signal output from the relative emphasis unit 230 by the second detail component signal, and outputs a synthesized image signal.

[0076] Finally, the processing device 200 generates a display image signal based on the synthesized image signal (step S40), outputs the display image signal to the display device 300 (step S50), and ends the image signal processing. Here, for example, the display image generation unit 250 generates a display image signal based on the synthesized image signal and outputs it to the display device 300.

[0077] As described above, by the processing device 200 performing Figure 2The image signal processing shown emphasizes the detail component signal relative to the base component signal, so that an endoscopic image with higher visual recognition than before can be obtained. In particular, by performing only gray-scale compression on the base component signal, the detail component signal including the contrast component is maintained as it is. Therefore, deterioration of the contrast due to the gray-scale compression process can be prevented, and higher visual recognition than before can be achieved. Also, in the gray-scale compression process, the same parameters as those used in the past are used, so that changes in hue caused by differences in the gray-scale compression process can also be suppressed. Therefore, differences in impressions caused by changes in hue can be suppressed, and the impact on the established diagnostics can be reduced infinitely.

[0078] In addition, by performing the Figure 2 image signal processing shown by the processing device 200, the base component signal is made to approach the image signal corresponding to the control parameter, so that the difference in impression from the conventional endoscopic image can be adjusted. More specifically, when the base component signal is gradually made to approach the image signal to become the state of the image signal itself (for example, α = 1), the detail component signal also becomes the same as the image signal. In this case, even if only the base component signal is compressed in the relative emphasis process, it is substantially the same as compressing the entire image signal, so the relative emphasis process performed by the relative emphasis unit 230 is almost the same as the conventional gray-scale compression process corresponding to the monitoring performance and the like. That is, the closer the base component signal is to the image signal, the smaller the degree of relative emphasis, and the closer the image signal for display is to the image signal of the conventional endoscopic image, and as a result, the difference in impression is smaller. Therefore, by adjusting the control parameter, the difference in impression from the conventional endoscopic image can be adjusted. In particular, by using the Alpha value as the control parameter, the impression can be finely adjusted by finely tuning the Alpha value, and for example, it is possible to cope with subtle differences in impression caused by individual differences.

[0079] Therefore, according to the processing device 200 according to the present embodiment, it is possible to simultaneously achieve a high level of improvement in visual recognition with respect to the conventional endoscopic image and adjustment of the difference in impression from the conventional endoscopic image.

[0080] [Second Embodiment]

[0081] Figure 6 is a diagram illustrating the configuration of the endoscopic system 2 according to the present embodiment. Figure 6 The endoscopic system 2 shown is different from the endoscopic system 1 in that it includes a processing device 200a instead of the processing device 200. In other respects, the endoscopic system 2 is the same as the endoscopic system 1, so the same reference numerals are assigned to the same components, and detailed description thereof is omitted.

[0082] The processing device 200a is different from the processing device 200 in that it has a relative emphasis unit 230a instead of the relative emphasis unit 230. The relative emphasis unit 230a is different from the relative emphasis unit 230 in that it performs signal processing to emphasize the first detail component signal relative to the first basic component signal not only on the first basic component signal but also on the first detail component signal. More specifically, the relative emphasis unit 230a includes an emphasis unit 232 in addition to the gray-scale compression unit 231.

[0083] The emphasis unit 232 performs emphasis processing on the first detail component signal received from the detail component extraction unit 223, thereby generating a second detail component signal and outputting it to the synthesis unit 240. The method of emphasis processing performed by the emphasis unit 232 is not particularly limited. The emphasis processing may be, for example, gain boosting processing using parameters, and the parameters used may be calculated by a function depending on the luminance value.

[0084] With the processing device 200a as well, similar to the processing device 200, it is possible to improve visual recognition with respect to conventional endoscopic images and to adjust the difference in impression from conventional endoscopic images. Also, in the processing device 200a, in addition to being able to suppress deterioration of contrast by not performing gray-scale compression on the detail signal component, that is, improving the relative contrast with respect to conventional endoscopic images, it is also possible to improve the absolute contrast by emphasizing the detail signal component. Therefore, according to the processing device 200a according to the present embodiment, higher visual recognition can be achieved compared to the processing device 200.

[0085] [Third Embodiment]

[0086] Figure 7 FIG. is a diagram illustrating the configuration of the endoscopic system 3 according to the present embodiment. Figure 7 The illustrated endoscopic system 3 is different from the endoscopic system 1 in that it has a processing device 200b instead of the processing device 200. In other respects, the endoscopic system 3 is the same as the endoscopic system 1, so the same reference numerals are given to the same components and detailed description is omitted.

[0087] The processing device 200b is different from the processing device 200 in that it has a segmentation unit 220a instead of the segmentation unit 220. The segmentation unit 220a is different from the segmentation unit 220 in that it directly generates the first basic component signal from the image signal, instead of generating the first basic component signal by mixing the original basic component signal generated from the image signal with the image signal. More specifically, the segmentation unit 220a includes a basic component extraction unit 221a instead of the basic component extraction unit 221 and the basic component adjustment unit 222.

[0088] The basic component extraction unit 221a extracts the basic component from the image signal received from the self-image signal processing unit 210 to generate a basic component signal, which is the same as the basic component extraction unit 221. In addition, regarding the method for extracting the basic component, for example, an edge-preserving smoothing filter such as a bilateral filter or an ε filter can also be used, which is also the same as the basic component extraction unit 221. However, the difference of the basic component extraction unit 221a is that it determines the filter according to the control parameter and uses the determined filter to smooth the image signal.

[0089] The basic component extraction unit 221a determines, for example, the kernel size and the coefficient of the filter according to the control parameter. In addition, according to the control parameter, one filter is selected from a plurality of filters prepared in advance, thereby determining the filter used in the filtering process. Thus, it is possible to adjust, by the control parameter, the degree to which the first basic component signal generated by the basic component extraction unit 221a approaches the image signal.

[0090] Figure 8 It is a flowchart of the signal segmentation process according to the present embodiment. In the processing device 200b, the Figure 2 shown image signal processing is also performed, but the processing device 200b performs the Figure 8 shown signal segmentation process in the signal segmentation process of step S10 to replace the Figure 3 shown signal segmentation process.

[0091] When Figure 8 the shown signal segmentation process starts, the processing device 200b first obtains the control parameter to determine the filter (step S61). Here, for example, the basic component extraction unit 221a reads the control parameter from the control parameter storage unit 291 to determine the filter used in the filtering process. In addition, the control parameter is determined according to the selection made in advance by the surgical operator.

[0092] Next, the processing device 200b smooths the image signal using the filter to generate a first basic component signal (step S62). Here, for example, the basic component extraction unit 221a performs the filtering process using the filter determined in step S61, thereby generating the first basic component signal.

[0093] Finally, the processing device 200b generates a first detail component signal (step S63) and ends the signal segmentation process. This process is the same as the Figure 3 processing of step S14 shown.

[0094] With the processing device 200b, similarly to the processing device 200, it is possible to improve visual recognition with respect to conventional endoscopic images and to adjust the difference in impression from conventional endoscopic images. Further, in the processing device 200b, the filter is changed according to the control parameter, whereby the base signal is made closer to the image signal. Therefore, the above-described effects can be obtained without significantly changing the structure of the existing processing device.

[0095] The above-described embodiments show specific examples for facilitating understanding of the invention, and the embodiments of the present invention are not limited to these. The image signal processing device, the image signal processing method, and the program can be variously modified and changed without departing from the scope described in the claims.

[0096] In Figure 1 , Figure 6 , Figure 7 an example in which the relative emphasis unit includes the gradation compression unit 231 is shown, but as long as the relative emphasis unit can emphasize the detail component signal with respect to the base component signal, the structure is not limited to including the gradation compression unit 231. The relative emphasis unit only needs to perform signal processing for emphasizing the first detail component signal with respect to the first base component signal on at least one of the first base component signal and the first detail component signal, and thereby output the second base component signal and the second detail component signal. That is, the relative emphasis unit only needs to include at least one of the gradation compression unit 231 and the emphasis unit 232.

[0097] In addition, in Figure 1 , Figure 6 , Figure 7 an example in which the processing device includes the light source unit is shown, but the processing device may not include the light source unit. The processing device may be connected to a light source device independent of the processing device, and may also perform dimming control of the illumination light provided to the endoscope 100 by controlling the light source device.

[0098] In addition, in Figure 1 , Figure 6 , Figure 7 an example in which the processing device is an endoscope processor included in an endoscope system is shown, but the processing device is not limited to an endoscope processor. For example, it may be an image signal processing device that performs image signal processing on the image signal of a microscope image obtained by a microscope device.

[0099] In addition, in Figure 1 , Figure 6 , Figure 7 an example in which the control parameter is pre-stored in the control parameter storage unit 291 included in the processing device is shown, but the control parameter may also be obtained from a device outside the processing device, such as a cloud server on the Internet, as needed.

[0100] Although not specifically mentioned, the processing of the basic component signal and the detail component signal in the dividing section and the relative emphasis section can also be performed for each color component. For example, the basic component signal and the detail component signal can also be generated for each of the R, G, and B color components, and then various processes can be performed.

[0101] In addition, Figure 2 , Figure 3 , Figure 8 Each process of the flowchart shown can also be performed by hardware processing. In addition, it can also be performed by software processing, which is performed by executing a program expanded in a memory.

[0102] In addition, the image signal processing device may also include Figure 1 , Figure 6 , Figure 7 structures other than those shown. For example, the image signal processing device may also have a brightness correction section between the dividing section and the relative emphasis section. The brightness correction section can perform a process of correcting the brightness value on the first basic component signal output from the dividing section to improve the brightness of the image.

[0103] In addition, Figure 1 , Figure 6 , Figure 7 The example shown in the image signal processing device shows that the gray level compression section compresses the first basic component signal. However, the signal compressed by the gray level compression section is not limited to the first basic component signal. For example, the relative emphasis section may also have a gray level compression section that performs gray level compression processing on any one of the image signal, the original basic component, and the first basic component signal, thereby generating a second basic component signal. In this case, the gray level compression section can also perform gray level compression signal processing on any one of the image signal, the original basic component, and the first basic component signal according to the settings specified by the user. For example, it may be that when no adjustment of the degree of emphasis is required, the original basic component signal is compressed. In addition, it may be that when adjusting the difference from the impression of the previous image and improving visual recognition, the first basic component signal is compressed. Thus, the user can appropriately select the image processing for improving the visual recognition of lesions according to the situation and use it.

[0104] Explanation of reference numerals

[0105] 1, 2, 3: Endoscope system; 100: Endoscope; 110: Optical system; 120: Imaging element; 121: Light-receiving section; 122: Readout section; 130: Light guide; 140: Illumination lens; 200, 200a, 200b: Processing device; 210: Imaging signal processing section; 220, 220a: Division section; 221, 221a: Basic component extraction section; 222: Basic component adjustment section; 223: Detail component extraction section; 230, 230a: Relative emphasis section; 231: Gray-scale compression section; 232: Emphasis section; 240: Synthesis section; 250: Display image generation section; 260: Control section; 270: Input section; 280: Light source section; 283: Light source control section; 282: Light source driver; 281: Light source; 290: Storage section; 291: Control parameter storage section; 300: Display device.

Claims

1. An image signal processing device, characterized in that, it comprises: a basic component extraction unit that extracts a basic component from the image signal to generate an original basic component signal; a basic component adjustment unit that performs a weighted average process on the image signal and the original basic component signal to generate a first basic component signal; a detail component extraction unit that extracts a detail component from the image signal based on the first basic component signal to generate a first detail component signal; a relative emphasis unit that performs signal processing to emphasize the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal; a synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; a storage unit that stores a plurality of control parameters related to the similarity between the image signal and the first basic component signal; and an input unit that receives an instruction from a user for selecting the control parameter, wherein the basic component adjustment unit acquires the control parameter selected in response to an input made by the user from the input unit among the plurality of control parameters stored in the storage unit, and the basic component adjustment unit performs the weighted average process using a weight coefficient determined according to the selected control parameter to generate the first basic component signal, wherein the weighted average process is an alpha blending process, the control parameter is an alpha value used in the alpha blending process, and the weight coefficient for the image signal is determined as the alpha value.

2. The image signal processing device according to claim 1, characterized in that, the relative emphasis unit comprises a gray level compression unit that performs gray level compression processing on the first basic component signal to generate the second basic component signal.

3. The image signal processing device according to claim 1, characterized in that, the relative emphasis unit comprises an emphasis unit that performs emphasis processing on the first detail component signal to generate the second detail component signal.

4. The image signal processing device according to claim 1, characterized in that, the basic component is a component in the image components included in the image signal that has a weaker correlation with what the eyes perceive compared to the detail component, and the detail component is a component in the image components that has a stronger correlation with what the eyes perceive compared to the basic component.

5. An image signal processing device, characterized in that, it comprises: a segmentation unit that segments the image signal into a first basic component signal and a first detail component signal according to a control parameter and outputs them; a relative emphasis unit that performs signal processing to emphasize the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, thereby outputting a second basic component signal and a second detail component signal; A synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; A storage unit that stores a plurality of the control parameters related to the similarity between the image signal and the first basic component signal; And An input unit that receives an instruction for selecting the control parameter from a user, wherein the segmentation unit segments the image signal into a first basic component signal and a first detail component signal and outputs them according to the control parameter selected in response to an input made by the user from the input unit among the plurality of control parameters stored in the storage unit; wherein the segmentation unit includes: A basic component extraction unit that extracts a basic component from the image signal to generate an original basic component signal; A basic component adjustment unit that performs a weighted average process on the image signal and the original basic component signal using a weight coefficient determined according to the selected control parameter to generate the first basic component signal; and A detail component extraction unit that extracts a detail component from the image signal based on the first basic component signal to generate the first detail component signal, The weighted average process is an alpha blending process, the control parameter is an alpha value used in the alpha blending process, and the weight coefficient for the image signal is determined as the alpha value.

6. An image signal processing apparatus, characterized in that it includes: A basic component extraction unit that extracts a basic component from an image signal to generate an original basic component signal; A basic component adjustment unit that performs a weighted average process on the image signal and the original basic component signal to generate a first basic component signal; A detail component extraction unit that extracts a detail component from the image signal based on the first basic component signal to generate a first detail component signal; A relative emphasis unit that performs signal processing for emphasizing the first detail component signal relative to the first basic component signal on at least one of the first basic component signal and the first detail component signal, and outputs a second basic component signal and a second detail component signal; A synthesis unit that synthesizes the second basic component signal and the second detail component signal to generate a synthesized image signal; A storage unit that stores a plurality of control parameters related to the similarity between the image signal and the first basic component signal; And An input unit that receives an instruction for selecting the control parameter from a user, wherein the basic component adjustment unit obtains the control parameter selected in response to an input made by the user from the input unit among the plurality of control parameters stored in the storage unit, and performs the weighted average process using a weight coefficient determined according to the selected control parameter to generate the first basic component signal, The relative emphasis unit includes a gray level compression unit that performs gray level compression processing on any one of the image signal, the original basic component signal, and the first basic component signal to generate the second basic component signal, Among them, the weighted average processing is alpha blending processing, the control parameter is the alpha value used in the alpha blending processing, and the weight coefficient for the image signal is determined as the alpha value.

7. An image signal processing method, characterized in that, extract a basic component from the image signal to generate an original basic component signal, perform weighted average processing on the image signal and the original basic component signal using a weight coefficient determined according to a control parameter selected in response to an input from a user selection instruction, thereby generating a first basic component signal, based on the image signal and the first basic component signal, extract a detail component from the image signal to generate a first detail component signal, perform signal processing on at least one of the first basic component signal and the first detail component signal to emphasize the first detail component signal relative to the first basic component signal, thereby outputting a second basic component signal and a second detail component signal, synthesize the second basic component signal and the second detail component signal, thereby generating a synthesized image signal, wherein the weighted average processing is alpha blending processing, the control parameter is the alpha value used in the alpha blending processing, and the weight coefficient for the image signal is determined as the alpha value.

8. A computer-readable storage medium storing a program, characterized in that, the program causes a computer to perform the following processing: extract a basic component from the image signal to generate an original basic component signal; perform weighted average processing on the image signal and the original basic component signal using a weight coefficient determined according to a control parameter selected in response to an input from a user selection instruction, thereby generating a first basic component signal; based on the image signal and the first basic component signal, extract a detail component from the image signal to generate a first detail component signal; perform signal processing on at least one of the first basic component signal and the first detail component signal to emphasize the first detail component signal relative to the first basic component signal, thereby outputting a second basic component signal and a second detail component signal; and synthesize the second basic component signal and the second detail component signal, thereby generating a synthesized image signal, wherein the weighted average processing is alpha blending processing, the control parameter is the alpha value used in the alpha blending processing, and the weight coefficient for the image signal is determined as the alpha value.

9. A computer program product comprising a computer program that, when run by a processor, performs the image signal processing method according to claim 7.

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