JP4459789B2 - Signal processing apparatus, imaging apparatus, and signal processing program - Google Patents

Description

  The present invention relates to a signal processing device, an imaging device, and a signal processing program, and in particular, a signal processing device for displaying information on a high-frequency signal component of an image included in a video signal with high accuracy even in a low-resolution monitor or the like. The present invention relates to an imaging device and a signal processing program.

  Conventionally, an imaging apparatus such as a camera is provided with a mechanism for adjusting the focus. Specifically, in a film camera, there are a range finder method using the principle of triangulation, a single-lens reflex camera that can visually recognize an optical image that has passed through a lens to be actually photographed, and the like.

  Further, in a television camera, a viewfinder including a small cathode ray tube or a liquid crystal monitor is attached to the camera as having an optical viewfinder, and focus adjustment is performed while viewing a captured image displayed on the screen. In addition, there is a technique of performing signal processing on a captured video signal in order to make it easier to understand the in-focus portion (see, for example, Patent Document 1).

  Furthermore, even when shooting with a high-definition imaging method such as high-definition, in order to improve the visibility in the viewfinder etc., sub-sampling the image included in the shot video signal and performing addition etc. There is a method for generating a signal (see, for example, Patent Document 2).

In this way, there is a method of extracting a high frequency signal component from a captured image and amplifying it in order to improve the visibility of the focus position (focus point), and then displaying the signal superimposed on the original video signal on the viewfinder. It is used.
JP 61-45691 A Japanese Patent Laid-Open No. 62-285585

  By the way, as shown in the conventional method, in order to selectively emphasize a predetermined frequency such as a high-frequency signal component, it is necessary to create a bandpass filter as a device configuration. Will be the number of taps. In addition, since a high frequency is extracted with a small number of taps, it is possible to design a certain amount of HPF (High Pass Filter), but as a result, even unnecessary high frequency signal components may be emphasized. There is.

  Further, in existing video systems such as high-definition televisions, a small display device capable of displaying an image with a resolution almost the same as a captured image has been developed as a viewfinder. Therefore, the focus adjustment can be performed almost accurately with the viewfinder attached to the camera head or the like by the method described above.

  However, when shooting with an imaging device such as an ultra-high-definition camera having a resolution exceeding the high-definition, there is no viewfinder having a considerable resolution, so it is necessary to reduce the resolution. It is very difficult to adjust the focus.

  Also, ultra-high-definition cameras, etc., may shoot out-of-focus images if focus adjustment is not performed more strictly than before, so high accuracy can be achieved even on low-resolution monitors such as viewfinders. There is a need for a camera system including a display device capable of performing focus adjustment.

  The present invention has been made in view of the above-described problems, and a signal processing apparatus and an imaging apparatus for displaying information on a high-frequency signal component of an image included in a video signal with high accuracy even in a low-resolution monitor or the like. And a signal processing program.

  The present invention solves the problem that a high-frequency signal component of an ultra-high-definition original image cannot be displayed on a low-resolution monitor such as a small screen. In order to solve the above-described problem, the present invention has the following characteristics. The means to solve is adopted.

The invention described in claim 1 is a signal processing device that performs signal processing for displaying a video signal captured by an imaging device on a display device having a resolution lower than the resolution of the video signal, and is included in the video signal. A dividing unit that divides the image to be divided into pixel block units of a preset size based on the resolution of the display device, and extracts the high frequency signal component amount of the image for each pixel block obtained by the dividing unit A high-frequency signal component amount extraction unit that sets a representative value for each pixel block from the extracted high-frequency signal component amount and adjusts the size of the set representative value based on the resolution of the display device; and the imaging device An image reduction unit that adjusts the size of the image included in the video signal captured in accordance with the resolution of the display device and generates a reduced image;
And a superimposing unit that superimposes the representative value obtained by the high-frequency signal component amount extracting unit on the reduced image obtained by the image reducing unit .

  According to the first aspect of the present invention, it is possible to display information relating to the high frequency signal component of the image included in the video signal even when displaying on a monitor or the like having a lower resolution than the resolution of the captured video signal. As a result, the user can achieve highly accurate focus adjustment.

  The invention described in claim 2 is characterized by comprising normalizing means for normalizing the image for each pixel block obtained by the dividing means.

  According to the second aspect of the present invention, it is possible to make uniform the difference in luminance level of the high frequency signal component extracted from the image included in the video signal between the bright part and the dark part of the photographing region.

  The invention described in claim 3 is characterized in that the high-frequency signal component amount extraction means extracts an image contour for each pixel block and sets a representative value based on the extracted contour information. .

  According to invention of Claim 3, a highly accurate representative value can be set based on outline information.

  According to a fourth aspect of the present invention, the high-frequency signal component amount extraction unit calculates a variance value of pixel values for each pixel block, and sets a representative value based on the calculated variance value. And

  According to the invention described in claim 4, since the dispersion value is used, the representative value can be set without depending on the frequency. Therefore, it is possible to reduce the influence of pulsed noise such as pixel defects and FPN (Fixed Pulse Noise).

  According to a fifth aspect of the present invention, the high-frequency signal component amount extraction unit is configured to increase the image area obtained by moving a pixel block set in advance from a predetermined position of the image in units of one pixel. It is characterized by extracting a region signal component amount.

  According to the fifth aspect of the present invention, the high-frequency signal component amount can be extracted with high accuracy. Thereby, a highly accurate representative value can be set.

  The invention described in claim 6 is characterized in that the high-frequency signal component amount extracting means reduces the high-frequency signal component amount to a predetermined image size by sub-sampling.

  According to the sixth aspect of the present invention, it is possible to display information relating to the high frequency signal component of the image included in the video signal even when displaying on a monitor or the like having a resolution lower than the resolution of the captured video signal.

  In the invention described in claim 7, the high-frequency signal component amount extraction unit calculates a variance value of pixel values from an optical black region included in the image, and calculates the calculated variance value and other pixel blocks. A representative value is set based on difference information from the obtained dispersion value.

  According to the seventh aspect of the present invention, it is possible to avoid the influence of the high-frequency signal component of the entire screen due to vertical stripe noise and non-uniform characteristics of each element in the pixel-shifted imaging method. Further, by setting a representative value based on the amount of the high frequency signal component, it is possible to display information on the high frequency signal component with higher accuracy.

  The invention described in claim 8 is an image pickup apparatus including the signal processing device according to any one of claims 1 to 7.

The invention described in claim 9 is a signal processing program for causing a computer to execute signal processing for displaying a video signal captured by an imaging device on a display device having a resolution lower than the resolution of the video signal . the computer, the image included in the video signal, based on the resolution of the display device, dividing means for dividing the pixel block unit of preset the size, the image for each pixel block obtained by said dividing means The high frequency signal component amount is extracted, the representative value for each pixel block is set from the extracted high frequency signal component amount , and the size of the set representative value is adjusted based on the resolution of the display device the amount extracting unit, an image included in the video signal captured by the image pickup device, the size adjusted on the basis of the resolution of the display device, generating a reduced image That the image reduction means, and causes function representative value obtained by the high frequency signal component extraction means as a superimposing means for superimposing the reduced image obtained by the image reduction unit.

  According to the ninth aspect of the present invention, it is possible to display information relating to the high frequency signal component of the image included in the video signal even when displaying on a monitor or the like having a lower resolution than the resolution of the captured video signal. As a result, the user can achieve highly accurate focus adjustment. In addition, signal processing can be realized at low cost without requiring a special device configuration. Furthermore, signal processing can be easily realized by installing a program.

  According to the present invention, even when displaying on a monitor or the like having a resolution lower than the resolution of the captured video signal, information on the high frequency signal component of the image included in the video signal can be displayed with high accuracy. As a result, the user can achieve highly accurate focus adjustment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments in which a signal processing device, an imaging device, and a signal processing program having the characteristics of the present invention are suitably implemented will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration example of an imaging system having a signal processing device according to the present invention. An imaging system 10 illustrated in FIG. 1 is configured to include an imaging device 11, a signal processing device 12, and a display device 13.

  The imaging device 11 is composed of a high-definition camera or the like, captures a subject or the like, and outputs the captured video signal to the signal processing device 12. The signal processing device 12 performs signal processing by dividing an image (original image) included in the video signal obtained from the imaging device 11 into blocks each having a preset size. Further, the signal processing device 12 outputs the video signal subjected to the signal processing to the display device 13.

  The display device 13 includes a small monitor typified by a viewfinder. That is, the display device 13 can display only an image having a resolution lower than the resolution of the video imaged by the imaging device 11, but the video signal signal-processed by the signal processing device 12 in the present invention is input. Therefore, the focus information of the original image based on the high frequency signal component can be displayed even on a low resolution monitor. As a result, the user can achieve highly accurate focus adjustment.

  In FIG. 1, the imaging device 11 and the signal processing device 12 are configured separately. However, in the present invention, the present invention is not limited to this, and each configuration of signal processing by the signal processing device 12 described later is included in the imaging device 11. May be provided. Further, the display device 13 may be provided in the imaging device 11.

<Signal Processing Device 12: Functional Configuration>
Next, the functional configuration of the signal processing device 12 will be described with reference to the drawings. FIG. 2 is a diagram illustrating an example of a functional configuration of the signal processing device according to the present invention. The signal processing device 12 shown in FIG. 2 includes a dividing unit 21, a normalizing unit 22, a high-frequency signal component amount extracting unit 23, an image reducing unit 24, and a superimposing unit 25.

  First, the signal processing device 12 inputs the video signal captured by the imaging device 11 to the dividing unit 21 and the image reducing unit 24. The dividing unit 21 divides each image frame included in the input video signal into blocks set in advance. Here, the block indicates, for example, an area in which the vertical and horizontal directions of the image frame are surrounded by m × n pixels (m, n ≧ 1), and the resolution of the display device 13 and the processing performance of the signal processing device 12 are considered. Based on this, the block size is set. The dividing unit 21 outputs the divided image to the normalizing unit 22.

  In order to make the luminance level difference of the high frequency signal component extracted by the high frequency signal component amount extracting means 23 uniform between the bright portion and the dark portion of the shooting region from the input image, the normalizing means 22 Normalize the image.

  The normalization process is represented by the following expression (1), where f (x, y) is an image signal in the target block.

正規化手段２２は、この正規化画像ｆ＾を高域信号成分量抽出手段２３に出力する。高域信号成分量抽出手段２３は、抽出された正規化画像を例えば高域通過フィルタ等により高域信号成分を抽出する。また、高域信号成分量抽出手段２３は、抽出された高域信号成分から画像の代表値を設定する。なお、代表値としては分割されたブロック毎の分散値や周波数分析手法等を用いる。

The normalizing means 22 outputs the normalized image f ^ to the high frequency signal component amount extracting means 23. The high-frequency signal component amount extraction unit 23 extracts high-frequency signal components from the extracted normalized image using, for example, a high-pass filter. Further, the high frequency signal component amount extracting unit 23 sets a representative value of the image from the extracted high frequency signal component. As the representative value, a variance value for each divided block, a frequency analysis method, or the like is used.

  Specifically, the variance value of the pixel value is calculated, and the calculated variance value is used as the high frequency signal component amount of each block, or the peak value of the absolute value of the high frequency signal extracted for each block is detected. The detected value can be set as the representative value of the block. A specific method for setting the representative value will be described later. Further, the high-frequency signal component amount extraction unit 23 adjusts the representative value by enlargement / reduction based on a resolution or the like preset in the display device 13, and outputs the adjusted representative value to the superimposing unit 25.

  The high-frequency signal component amount extracting unit 23 may control the signal so that the extracted high-frequency signal portion is flickered and displayed on the display device 13, and may output control information related to the control to the superimposing unit 25. it can. Thereby, it is possible to make the user easily view the focus information as auxiliary information for focus adjustment based on the high frequency signal component on the display device 13.

  On the other hand, the image reduction means 24 adjusts each image included in the video signal by enlarging or reducing the video signal input from the imaging device 11 based on a resolution or the like preset in the display device 13. In addition, the image reducing unit 24 outputs the adjusted image to the superimposing unit 25.

  The superimposing means 25 superimposes the representative value or control information input by the high frequency signal component amount extracting means 23 and the corresponding reduced image obtained by the image reducing means 24. In addition, the superimposing unit 25 outputs the superimposed video signal to the display device 13. Thereby, even when displaying on the display device 13 including a monitor having a lower resolution than the resolution of the captured video signal, information (representative value) regarding the high frequency signal component of the image included in the video signal is displayed as the focus information. can do. In addition, the user can realize highly accurate focus adjustment from the focus information based on the high frequency signal component output to the display device 13.

  In the configuration example shown in FIG. 2, the original image, the representative value, and the like, which are adjusted by enlarging / reducing each corresponding to the resolution of the display device 13, etc. are superimposed. However, the present invention is not limited to this. For example, the superposed video signal may be adjusted by enlarging or reducing in accordance with the resolution of the display device 13 or the like. Further, in the configuration of FIG. 2, the high frequency signal component amount can be extracted and the representative value can be set even if the configuration does not include the normalizing unit 22, and the present invention can be applied.

  Next, an example of setting a representative value in the above-described high frequency signal component amount extracting unit 23 will be described.

<First setting example: representative value setting by extracting the maximum value for each block>
In the first setting example, the maximum value of the high frequency signal obtained from the image for each block is set as the representative value. Specifically, first, a high-frequency signal component is extracted from the original image using a high-pass filter (HPF) or the like.

  Here, generally, the contour portion of the image is a portion where the density greatly changes, and thus the signal of this portion includes a high frequency region. Therefore, in the first setting example, contour extraction is performed as high-frequency signal extraction.

  The contour is a line representing the outer edge of the object or a line element characterizing the image, and extracting the contour is called “contour extraction” or “edge extraction”. That is, since the boundary between the object and the object in the image or the boundary between the object and the background is a contour, a portion where there is a sudden change in the density or color of the image appears as a contour. Therefore, it is only necessary to pay attention to the density for contour extraction. That is, since the contour is a portion where the density value changes abruptly, a differential operation for extracting a change in function is used for contour extraction.

  Here, the differentiation includes a primary differentiation (gradient) and a secondary differentiation (Laplacian), both of which can be used for contour extraction. The gradient represents the gradient of density at a position (x, y) of a certain image and is suitable for edge detection. Laplacian is a value of a second derivative obtained by differentiating the gradient once again. Actually, the differential value is taken instead of the differential value.

  In the present invention, in addition to the gradient and the Laplacian, the interval for taking the difference is wider than that of a normal gradient. Etc. can be used.

  Therefore, in the first setting example, the gradient of the image signal that is the contour information is calculated by, for example, primary differentiation for each block, and the maximum value of the gradient in the block is set as the representative value. Thereby, the representative value of the high-frequency component amount can be set with high accuracy by contour extraction.

In this case, the maximum absolute value of the high frequency signal in the block having a preset image size (for example, n × n pixels) is extracted. Therefore, the image size of the extracted representative value is 1 / n ² of the original image.

<Second setting example: representative value setting by variance value>
In the second setting example, a dispersion value obtained from an image for each block is set as a representative value. Specifically, when the image included in the video imaged by the imaging device 11 is normally in focus, when only the portion in focus is viewed, it is in a high contrast state In other words, the difference in luminance level around it is large. Therefore, by taking the dispersion value in the block, the pixel value in the in-focus portion is dispersed compared to the out-of-focus portion, so the dispersion value should be large.

Note that the variance value is calculated from the average μ in the following equation (2) (3), where x ₁ , x ₂ ,..., X _n are pixel values in the block divided into a predetermined size. The variance σ ² of the equation can be calculated.

このようにして得られた分散値を高域信号成分量として出力する。また、ブロック毎に分散値を算出し、算出された分散値の振幅値を輝度レベルに置換し、置換された輝度レベルをそれぞれの画像ブロックの代表値とする。

The dispersion value thus obtained is output as a high frequency signal component amount. Further, a variance value is calculated for each block, the amplitude value of the calculated variance value is replaced with a luminance level, and the replaced luminance level is used as a representative value of each image block.

  Thereby, since the dispersion value is used, the representative value can be set without depending on the frequency. Therefore, the influence of pulse noise such as pixel defects and FPN can be reduced as compared with the case where a high-pass filter or the like is used.

In the second setting example, one representative value is output for each block (for example, n × n pixels), so that the output image size is 1 / n ² of the image size of the original image.

  Here, the flow of signal processing in the first and second setting examples described above will be described with reference to the drawings. FIG. 3 is a diagram illustrating an example of the flow of signal processing in the first and second setting examples. FIG. 3 shows signal processing for reducing an image as an example of the present invention.

As shown in FIG. 3, the original image included in the video signal is divided into blocks of a predetermined size (n × n pixels in FIG. 3), and normalization is performed for each divided small block. Next, a representative value is set according to the first or second setting example described above, and an image composed of representative value information reduced to 1 / n ² is obtained. In addition, the reduced original image in the present invention can be acquired by superimposing the 1 / n ² image simply reduced from the original image and the representative value information. Then, a video signal including the reduced original image group is output to the display device 13.

  Thereby, even when displaying on the display device 13 including a monitor having a lower resolution than the resolution of the captured video signal, information (representative value) regarding the high frequency signal component of the image included in the video signal can be displayed. it can. In addition, the user can realize highly accurate focus adjustment from the focus information based on the high frequency signal component output to the display device 13.

<Third setting example: Set a representative value by sliding a block in pixel units>
FIG. 4 is a diagram illustrating an example for describing a third setting example of representative values in the present invention. In the third setting example, after the representative value is set in advance corresponding to the image size of the original image, the image size is reduced in accordance with the display device.

  Specifically, in the third setting example, a pixel block of a predetermined size (for example, n × n pixels) is slid pixel by pixel in the X or Y direction shown in FIG. 4 with respect to the pixels of the original image. However, the signal processing of the block at each position is performed, and the calculation processing result is set as a representative value.

  As shown in FIG. 4, a block of n × n pixels is moved in units of pixels, a representative value is obtained at each position as shown in the first setting example or the second setting example, and the obtained representative value is obtained. Is the high frequency signal component amount of the pixel at the position corresponding to the block position. Thereby, a contour image having the same image size as the original image can be extracted.

  Note that the above-described processing can improve the image accuracy because the high-frequency signal component including the image information of the peripheral pixels can be calculated. Further, by using the representative value of the contour image, focus information can be displayed on, for example, a high-resolution large-screen monitor, and a more accurate image can be displayed.

  Further, since the contour image obtained by the third setting example has the same image size as the original image, when displayed on a low-resolution small monitor or the like, as shown in an example of subsampling in FIG. The reduced image can be extracted by dividing the contour image into predetermined blocks and performing sub-sampling for each divided block and extracting the high-frequency signal component amount.

  Here, the influence of the high-frequency signal component of the entire screen due to the vertical stripe noise and the non-uniform characteristics of each element in the pixel-shifted imaging method is the influence of the high-frequency signal component amount of the output image. Appears as a uniform offset component.

  Therefore, in a conventional solid-state image sensor such as a CCD (Charge Coupled Device), the edge of the screen (for example, the right edge and the upper edge) is used to compensate for changes in the characteristics of the image sensor due to temperature changes. There is an area called optical black (OB) which is a light shielding area.

  In the present invention, in the above-described setting of the representative value, by removing the high-frequency signal component amount obtained from the optical black area from the entire screen, the characteristics of each element in non-uniform characteristics such as vertical stripe noise and pixel-shifted shooting are reduced. It is possible to avoid the influence of the high-frequency signal component of the entire screen caused.

  Here, the above-mentioned content is demonstrated using figures. FIG. 6 is a diagram illustrating an example of signal processing corresponding to optical black and optical black. 6A is a diagram illustrating an example of an optical black area, and FIG. 6B is a diagram illustrating an example of the flow of signal processing.

  As shown in FIG. 6A, the optical black area area 60 exists, for example, around the effective pixel area. Therefore, as shown in FIG. 6B, the high-frequency signal component amount in the optical black area for the block corresponding to the optical black area is deleted from the effective pixel area. In this case, not only the high frequency signal component but also the offset component is deleted.

  Here, the signal processing will be specifically described. A dispersion value obtained from an optical black area included in an image is obtained as a reference level, and a representative value is obtained from a value obtained by subtracting the reference level from a dispersion value obtained from another block. Set. The representative value setting example in FIG. 6B is an application of the second setting example described above, but the setting method of the first setting example can also be used.

  Thereby, the representative value for the block of the effective pixel area can be obtained with high accuracy. As a result, more accurate focus information can be output to the display device.

  Here, the signal processing device 12 according to the present invention can perform the signal processing according to the present invention using the dedicated device configuration described above, but generates an execution program that can cause the computer to execute the processing in each configuration. For example, the signal processing in the present invention can be realized by installing the program in a general-purpose personal computer, workstation, or the like.

<Hardware configuration>
Here, a hardware configuration example of a computer capable of executing signal processing in the present invention will be described with reference to the drawings. FIG. 7 is a diagram illustrating an example of a hardware configuration capable of realizing signal processing according to the present invention.

  7 includes an input device 71, an output device 72, a drive device 73, an auxiliary storage device 74, a memory device 75, a CPU (Central Processing Unit) 76 for performing various controls, and a network connection device. 77, which are connected to each other by a system bus B.

  The input device 71 has a pointing device such as a keyboard and a mouse operated by a user, and inputs various operation signals such as execution of a program from the user. The output device 72 has a display (monitor) for displaying various windows and data necessary for operating the computer main body for performing processing in the present invention, and the execution process of the signal processing program by the control program of the CPU 76. And results can be displayed.

  Here, in the present invention, the execution program installed in the computer main body is provided by, for example, a recording medium 78 such as a CD-ROM. The recording medium 78 on which the program is recorded can be set in the drive device 73, and the execution program included in the recording medium 78 is installed from the recording medium 78 to the auxiliary storage device 74 via the drive device 73.

  The auxiliary storage device 74 is a storage means such as a hard disk, and can store an execution program according to the present invention, a control program provided in a computer, etc., and perform input / output as necessary.

  The CPU 76 performs various operations and input / output of data with each hardware component based on a control program such as an OS (Operating System) and an execution program read and stored by the memory device 75. Each process in the signal processing can be realized by controlling the process. Various information necessary during the execution of the program can be acquired from the auxiliary storage device 74 and can also be stored.

  The network connection device 77 obtains an execution program from another terminal connected to the communication network by connecting to a communication network or the like, or an execution result obtained by executing the program or an execution in the present invention The program itself can be provided to other terminals.

  With the hardware configuration described above, signal processing can be realized at low cost without requiring a special device configuration. Moreover, signal processing can be easily realized by installing a program. Next, a processing procedure in the execution program will be described using a flowchart.

<Signal processing>
FIG. 8 is a flowchart of an example showing a signal processing procedure using the signal processing program in the present invention. FIG. 8 shows an example of signal processing of the present invention in the case where a video signal is output to a display device having a resolution lower than the resolution of the captured video signal.

  First, a video signal shot by an imaging device or a video signal shot and stored in advance is input (S01), and an image included in the input video signal is divided into blocks of a preset size ( S02).

  Next, normalization processing is performed for each divided image block (S03), and the high frequency signal component amount is extracted for each normalized image block based on the above setting example (S04). A representative value is set from the region signal component amount (S05).

  On the other hand, each image included in the video signal input in S01 is reduced based on the resolution of the display device to be displayed (S06). Next, the reduced image obtained in S06 and the representative value set in S05 are superimposed (S07), and the superimposed reduced video is output (S08).

  With the signal processing described above, it is possible to easily check the focus even when a video image taken by a high-definition imaging device is displayed on a small monitor with low image quality.

  As described above, according to the present invention, even when displaying on a monitor or the like having a resolution lower than the resolution of the captured video signal, it is possible to display information on the high-frequency signal component of the image included in the video signal with high accuracy. it can. As a result, the user can easily confirm the in-focus range on the monitor even with a low-resolution monitor, and high-accuracy focus adjustment can be realized.

  Further, by using the representative value in the present invention, the position, amount, distribution, etc. of the high-frequency signal of the original image can be displayed even on a monitor with low resolution. This makes it easy to see the high-frequency signal component amount that could not be displayed on a relatively small screen such as a viewfinder, and further adjusts the focus of the television camera by displaying the flicker superimposed on the image. Can be easily and reliably performed.

  In the above-described embodiment, the signal processing in the case where the image size is reduced and displayed mainly from the image size of the original image has been described. However, by applying the present invention, for example, the image size is the same and the resolution is different. In addition, when outputting to a display device that can display an enlarged image with a resolution higher than that of the captured video signal, the representative value is set by adding the representative value to the video signal as described above. It is possible to display a high-definition image by converting the resolution and the like based on the above.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

It is a figure which shows the example of 1 structure of an imaging | photography system. It is a figure which shows an example of a function structure of the signal processing apparatus in this invention. It is a figure which shows an example of the flow of the signal processing in the 1st, 2nd setting example. It is a figure of an example for demonstrating the 3rd example of a representative value setting in this invention. It is a figure which shows an example of subsampling. It is a figure which shows an example of the signal processing corresponding to optical black and optical black. It is a figure which shows an example of the hardware constitutions which can implement | achieve the signal processing in this invention. It is a flowchart of an example which shows the signal processing procedure using the signal processing program in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shooting system 11 Imaging device 12 Signal processing device 13 Display device 21 Dividing means 22 Normalizing means 23 High frequency signal component amount extracting means 24 Image reducing means 25 Superimposing means 60 Optical black area 71 Input device 72 Output device 73 Drive device 74 Auxiliary Memory device 75 Memory device 76 CPU
77 Network connection device 78 Recording medium

Claims (9)

In a signal processing device that performs signal processing for displaying a video signal captured by an imaging device on a display device having a resolution lower than the resolution of the video signal ,
A dividing unit that divides an image included in the video signal into pixel block units having a predetermined size based on the resolution of the display device ;
The high-frequency signal component amount of the image is extracted for each pixel block obtained by the dividing unit, a representative value for each pixel block is set from the extracted high-frequency signal component amount, and the set representative value is set to the display device. High-frequency signal component extraction means for adjusting the size based on the resolution of
Image reduction means for adjusting the size of the image included in the video signal captured by the imaging device based on the resolution of the display device and generating a reduced image;
And a superimposing unit that superimposes the representative value obtained by the high-frequency signal component amount extracting unit on the reduced image obtained by the image reducing unit .   The signal processing apparatus according to claim 1, further comprising a normalizing unit that normalizes an image for each pixel block obtained by the dividing unit. The high frequency signal component amount extraction means includes
The signal processing apparatus according to claim 1, wherein a contour of an image is extracted for each pixel block, and a representative value is set based on the extracted contour information. The high frequency signal component amount extraction means includes
The signal processing apparatus according to claim 1, wherein a variance value of pixel values is calculated for each pixel block, and a representative value is set based on the calculated variance value. The high frequency signal component amount extraction means includes
5. The high-frequency signal component amount is extracted from an image area obtained by moving a predetermined pixel block from a predetermined position of the image in units of one pixel. The signal processing device according to claim 1. The high frequency signal component amount extraction means includes
The signal processing apparatus according to claim 5, wherein the high-frequency signal component amount is reduced to a predetermined image size by sub-sampling. The high frequency signal component amount extraction means includes
A dispersion value of a pixel value is calculated from an optical black area included in the image, and a representative value is set based on difference information between the calculated dispersion value and a dispersion value obtained from another pixel block. The signal processing device according to any one of claims 1 to 6.   An imaging apparatus comprising the signal processing apparatus according to claim 1. In a signal processing program for causing a computer to perform signal processing for displaying a video signal captured by an imaging device on a display device having a resolution lower than the resolution of the video signal ,
The computer,
The images included in the video signal, based on the resolution of the display device, dividing means for dividing the pixel block unit of preset the size,
The high-frequency signal component amount of the image is extracted for each pixel block obtained by the dividing unit, a representative value for each pixel block is set from the extracted high-frequency signal component amount, and the set representative value is set to the display device. High-frequency signal component amount extraction means for adjusting the size based on the resolution of
An image reduction unit that adjusts the size of an image included in the video signal captured by the imaging device based on the resolution of the display device, and generates a reduced image; and
A signal processing program for causing a representative value obtained by the high-frequency signal component amount extracting means to function as a superimposing means for superimposing the representative value on a reduced image obtained by the image reducing means .

Images