JP2007057599A - Image signal processing apparatus, image signal processing method and image signal processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make image quality correction unnecessary at an image display device side as a user corrects image quality by integrating an element of audio visual environment using a function of a camera which is built in an image recording and reproducing device into a setting of image processing. <P>SOLUTION: The image signal processing apparatus of the invention communicates with an external image display device 36 by a communication means 35 in order to display image information to which image signal processing is performed on the external image display device 36. A microcomputer 17 acquires information regarding image display capability of the image display device 36 and performs image quality correction which suits a display characteristic of the image display device 36 by correcting a parameter of the image signal processing by a camera signal processing section 9 according to the acquired display capability of the image display device 36. Then, by measuring data regarding the audio visual environment of the image display device 36 by an image sensor 6, and by further correcting the parameter of the image signal processing by the camera signal processing section 9, based on the data regarding the audio visual environment, the image quality correction is performed which suits the audio visual environment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image signal processing apparatus, an image signal processing method, and an image signal processing system applied to, for example, a camera-integrated recording / playback apparatus that can be connected to a television monitor.

Conventionally, it is a digital camera that can be connected to an image display device such as a TV monitor, and the display performance information such as screen size, aspect ratio, γ characteristics, resolution, hue, and compatible image format of the image display device is Images that are obtained by communication from a memory in the display device or a server on the Internet, set image processing parameters based on this information, correct the image quality suitable for the display device, and output, record, and play back camera signals. A video recording / reproducing apparatus, an image processing apparatus, and a method are known (see Patent Document 1, Patent Document 2, and the like).
Japanese Patent Laid-Open No. 2004-320614 JP 2003-259207 A

  However, the digital cameras described in Patent Document 1 and Patent Document 2 can display images optimally in a certain standard viewing environment, but the ambient brightness during viewing and the distance to the connected image display device The environment in which the user actually watches is not considered. For this reason, in the case where the elements regarding the viewing environment are different, it cannot be said that the display is actually performed with the image quality preferable for the user. Accordingly, there has been a disadvantage that the display quality of the captured image is deteriorated.

  For example, when the output of the image display device is displayed with a normal brightness setting in a completely dark room, the screen becomes dazzling. In addition, when the screen size is not so large and the viewing distance is long (far), even if the source of the image signal is originally extended to a high frequency range, the detail part is difficult to see and the edge part looks sharp. No state. On the other hand, when the distance to the image display device is sufficiently short, there may be a case where the image looks unnatural when the image is contour-enhanced.

These viewing states depend on the human eyes having a wide adjustment range and the function of adjusting the input light by incorporating the surrounding viewing environment of the image display unit.
Also known as image display devices are those that can adjust the image quality such as screen brightness, gradation characteristics, frequency characteristics, and hue regardless of the input image signal. If these corrections are performed regardless of the signal, there is a problem that image quality deterioration such as deterioration in luminance and color reproducibility, increase in quantization noise, and other S / N deterioration may occur.

  In view of these circumstances, in the present invention, the user can incorporate the elements of the viewing environment into the image processing settings by using the function of the camera built in the image recording / reproducing apparatus, and can correct the image quality. An object of the present invention is to provide an image signal processing device, an image signal processing method, and an image signal processing system that do not require correction on the display device side.

  In order to solve the above problems and achieve the object of the present invention, an image signal processing apparatus of the present invention is provided between an image display apparatus and an image display apparatus for displaying image information subjected to image signal processing on an external image display apparatus. Communication means for communicating, acquisition means for acquiring information on image display performance of the image display device, and correction of image signal processing parameters by the image signal processing means according to the image display performance of the image display device acquired by the acquisition means A first correction unit that performs image quality correction that matches the display characteristics of the image display device, a measurement unit that measures data related to the viewing environment of the image display device using the imaging unit, and a further image based on the data related to the viewing environment. Second correction means for performing image quality correction suitable for the viewing environment by correcting image signal processing parameters by the signal processing means. A.

  The image signal processing method of the present invention includes a communication step of communicating with an image display device in order to display image information subjected to image signal processing on an external image display device, and an image display of the image display device. An acquisition step for acquiring information relating to performance, and a first image quality correction adapted to display characteristics of the image display device by correcting parameters of image signal processing according to the image display performance of the image display device acquired in the acquisition step. Correction step, a measurement step of measuring data related to the viewing environment of the image display device by imaging, and further correcting image signal processing parameters based on the data related to the viewing environment to perform image quality correction suitable for the viewing environment And a second correction step.

  In the image signal processing system of the present invention, the image signal processing device includes communication means for communicating with the image display device in order to display the image information subjected to the image signal processing on an external image display device; An acquisition unit that acquires information on the image display performance of the image display device, and a parameter of the image signal processing performed by the image signal processing unit according to the image display performance of the image display device acquired by the acquisition unit. First correction means for correcting image quality suitable for display characteristics, measurement means for measuring data relating to the viewing environment of the image display apparatus by the imaging means, and image signal processing by the image signal processing means based on data relating to the viewing environment A second correction unit that performs image quality correction suitable for the viewing environment by correcting the parameters of the external image display device. Those having a storage means for storing information on the image display performance of the image display device.

  According to the image signal processing apparatus, the image signal processing method, and the image signal processing system of the present invention described above, for example, the screen size, aspect ratio, γ characteristic, and resolution of an image display apparatus such as a television, a display, a monitor, and a projector. Information on image display performance such as hue and corresponding image format is acquired via communication means with the image display device. It is also possible to acquire information on the image display performance through communication with a data server on the Internet, and further, it is possible to acquire information on the image display performance of the image display device from a removable recording medium. I can do it.

  Then, it is possible to perform image quality correction in accordance with the display characteristics of the image display device by correcting the parameters of the image signal processing according to the image display performance or function information of the image display device acquired by the acquisition means. This image quality correction is performed by the first correction means. In addition, viewing environment data such as viewing environment brightness and viewing distance is measured and stored by the built-in imaging means, and based on this viewing environment data, image quality correction suitable for the viewing environment can be performed. Become. This image quality correction is performed by the second correction means.

  According to the present invention, a user is incorporated in an image signal processing apparatus, an image signal processing method, and an image signal processing system that are applied to a camera-integrated recording / playback apparatus that can be connected to an image display apparatus such as a television monitor. Since the elements of the viewing environment measured by the image pickup means are incorporated into the image processing settings by the second correction means to enable image quality correction, correction on the image display device side becomes unnecessary, and the display quality of the picked-up image is displayed. The effect that can be improved.

Embodiments of the present invention will be described below with reference to the drawings as appropriate.
FIG. 1 shows a system configuration diagram as an embodiment of the present invention.
In FIG. 1, an image recording / reproducing apparatus 1 includes an optical system 2 including a zoom lens 3, a focus lens 4, and an iris 5 that captures light for imaging into an image sensor 6, and a zoom lens 3, a focus lens 4, and an iris. 5 includes an optical system driver / actuator 19 including 20, 21, and 22 for driving each optical system 2, and an image sensor 6, a timing generator 40 and a driver 23 for driving the image sensor 6.

  In addition, the image recording / reproducing apparatus 1 includes an analog front end unit 7 that performs processing such as sample-holding, black level clamping, and gain control on an output signal from the image sensor 6, and an A / D converter that converts the output into a digital signal. The digital signal image captured by the image sensor 6 can be recorded, transmitted, and displayed so that the brightness, color balance, frequency characteristics, gradation characteristics, hue, saturation, number of pixels, etc. can be adjusted and converted. And a camera signal processing unit 9 for performing signal processing.

  The camera signal processing unit 9 includes an input unit capable of processing not only a signal from the image sensor 6 side but also a reproduction signal from a recording medium to be described later and an image signal from an external stream.

FIG. 2 shows a block configuration example of the camera signal processing unit 9.
In FIG. 2, the camera signal processing unit 9 converts the luminance signal and color difference signal input 41 (Y, RY, BY) from the recording medium and the external stream system into three primary color signals (R, G, B). Matrix section 42, black clamp section 44 for clamping the black level of the three primary color signals (R, G, B) from the image sensor 6 side, and switches 45, 46 for switching the outputs of the matrix section 42 and the black clamp section 44. , 47.

  The camera signal processing unit 9 also performs a gain adjustment unit 48 that performs gain adjustment processing of the three primary color signals (R, G, B), and white balance processing of the three primary color signals (R, G, B) after gain adjustment. A white balance unit 49 that performs gamma conversion (1 / γ) unit 50 that performs gamma conversion (1 / γ) processing of the three primary color signals (R, G, B) after white balance processing, and gamma conversion (1 / γ) A luminance conversion matrix unit 51 that performs luminance conversion of the processed three primary color signals (R, G, B) and outputs a luminance signal; and a low-pass filter that passes through the low-frequency component of the luminance signal after luminance conversion ( LPF) 52.

  The camera signal processing unit 9 also extracts a high frequency component of the three primary color signals (R, G, B) after white balance processing and outputs a luminance signal, and a luminance signal after the high frequency component extraction. A gain adjustment unit 54 that performs the gain adjustment process, and an addition unit 55 that outputs the luminance signal (Y) by adding the luminance signal after gain adjustment and the luminance signal after passing through the low-frequency component. Yes.

  The camera signal processing unit 9 also has a black clamp unit 44, a gain adjustment unit 48, a white balance unit 49, a gamma conversion (1 / γ) unit 50, and a luminance conversion matrix unit 51 via the control bus 56. Among the low-pass filter (LPF) 52, the high-frequency component extraction filter 53, the gain adjustment unit 54, the detection unit 59, the low-pass filter (LPF) 60, and the hue (HUE) gain matrix unit 61. A microcomputer interface unit 57 is provided for interfacing control signals and data with the computer 58.

  The camera signal processing unit 9 also determines the brightness and color of the light source relative to the reference level from the three primary color signals (R, G, B) after gain adjustment and the three primary color signals (R, G, B) after white balance processing. A detector 59 for detecting temperature, a low-pass filter (LPF) 60 that passes through the low-frequency components of the three primary color signals (R, G, B) after the gamma conversion (1 / γ) processing, and the low-pass components A hue (HUE) / gain matrix unit 61 for synthesizing the hue (HUE) and gain of the three primary color signals (R, G, B) for processing and outputting a color difference signal (RY, BY) is provided. Yes.

  Thereby, the camera signal processing unit 9 outputs the luminance signal (Y) output from the adding unit 55 and the color difference signals (RY, BY) output from the hue (HUE) / gain matrix unit 61 as image signals. Output as output 62.

  Returning to FIG. 1, the image recording / reproducing apparatus 1 converts the number of pixels of the image signal from the camera signal processing unit 9, the reproduction signal from the recording medium 28, and the input image signal from the external stream interface 29 as necessary. The number-of-pixels conversion units 11 and 13 displayed on the image display unit 15 such as an LCD (liquid crystal display) panel by performing equal processing, and the image display unit such as an LCD panel according to instructions from the microcomputer 17 to these image signals A baseband having a GUI generation and superposition unit 12 that superimposes and outputs a GUI (graphical user interface) on the output for 15 and the output for the external image display device 36, and an OSD (on screen display) generation and superposition unit 14 A signal processing unit 10 is provided.

  The image recording / reproducing apparatus 1 also includes an image display apparatus 15 such as an LCD panel for displaying an image signal on the camera side after baseband signal processing, a reproduction signal from a recording medium, an input image from an external stream, a GUI, and the like. I have. The image display device 15 is mounted on the image recording / reproducing apparatus main body. The camera unit is configured by the above-described units.

  Further, the image recording / reproducing apparatus 1 performs compression / expansion to record an output signal from the camera signal processing unit 9 on a recording medium, or reproduces a signal recorded on the recording medium, or is input from the outside. Alternatively, code amount compression / expansion units 25 and 26 for compressing / decompressing an image signal in a stream output to the outside, and error correction for recording on a recording medium and converting the recording medium into a form suitable for reproduction or stream transmission processing A recording / playback / transmission processing unit 27 that performs processing and the like, a built-in or removable recording media unit 28, and a removable recording media unit 34 are provided.

  The image recording / playback apparatus 1 also converts the external stream interface unit 29 that performs stream input / output processing, the camera signal processing unit 9, and the decompressed image data into an image format or color space suitable for the image display device 36. An output format conversion unit 30 that performs conversion as necessary, and an image signal interface unit 31 that transmits an image signal to the image display device 36 are provided.

  Further, the image recording / reproducing apparatus 1 includes a user interface 18 that performs an input operation for controlling each unit by a user operation, a display device information interface unit 32 that can acquire display performance information of the image display device 36 by communication, Communication means 35 that is an interface unit with a network server and the like, parameters for controlling each unit by the microcomputer 17, information data of the image display device acquired by communication, and viewing environment information acquired by user operation EEPROM (electrical erasable read only memory) 33 which is a non-volatile memory for storing the memory, and a host microcomputer 17 which automatically or fixedly controls each part based on operation information from the user interface 18. Composed.

  The external image display device 36 connected to the outside is a non-volatile memory that internally stores display performance information such as its screen size, aspect ratio, γ characteristics, resolution, hue, and corresponding image format. A display device information interface unit 38 having a display device information EEPROM 39 and capable of transmitting information stored therein through communication with the image recording / reproducing apparatus 1 through the information communication means 35, and display of image signals from the image recording / reproducing apparatus 1 And an image signal interface unit 37 for performing reception.

  The display device information data in the display device information EEPROM 39 in the image display device 36 preferably conforms to EDID (Extended Display Identification Data) of VESA (Video Electronics Standards Association) standard.

Hereinafter, an image quality correction operation suitable for the viewing environment of the image recording / reproducing apparatus 1 configured as described above will be described.
The image recording / reproducing apparatus 1 used in the embodiment of the present invention processes not only a signal from the image sensor 6 side but also a reproduction signal from the recording medium 28 and an image signal from an external stream from the external stream interface unit 29. Is possible.
The user interface 18 can also select whether or not to perform image quality correction processing suitable for the viewing environment.

First, an image quality correction processing method suitable for the viewing environment will be described.
The image quality correction processing method suited to the viewing environment includes the following processes.
First, viewing environment information is taken into the image recording / reproducing apparatus 1 and stored in the EEPROM 33.
Next, display performance information of the image display device 36 is acquired and stored in the EEPROM 33.
Then, the image quality is corrected so as to be suitable for the viewing environment by using the viewing environment information and the display performance information of the image display device 36 together with the camera signal processing parameters in the camera signal processing unit 9 at the time of imaging, recording and reproduction. .
Either the viewing environment information described above or the display performance information of the image display device 36 may be taken in first.

In the following, a description will be given of a process for capturing and storing the above-described viewing environment information in the image recording / reproducing apparatus.
FIG. 3 shows a state in which viewing environment information is taken into the image recording / reproducing apparatus, and particularly shows an example of an operation situation when the information is taken in.
In FIG. 3, the user 72 turns off the display operation of the image display device 36 or turns off the power and restricts the daylighting state 71 or adjusts the brightness of the room by the ambient lighting brightness 73 or the like. The optimal state for viewing is set.

  Then, the camera unit of the image recording / reproducing apparatus 1 is activated, and the image display device 36 is imaged from the viewing position. At this time, by setting the focusing operation in the camera signal processing unit 9 to autofocus, the viewing distance 74 corresponding to the drive position of the focus lens 4 can be measured. Further, by setting the exposure mode to an operation by automatic exposure, it is possible to measure the ambient brightness 73 indicating the exposure amount corresponding to the drive position of the iris 5. In addition, the operation mode of the image recording / reproducing apparatus 1 is set to a mode for taking in information of viewing environment by the user interface 18 such as a GUI or an external operation switch.

  In this state, distance information from the viewing position to the image display device 36 is captured, and the image display device 36 is focused from the viewing position using the autofocus function. In this case, it is desirable to place the zoom lens on the tele side as much as possible. Then, the microcomputer 17 of the image recording / reproducing apparatus 1 changes the viewing position from the position of the focus lens 4 to the viewing position by an operation for instructing the viewing environment information capturing operation using the user interface 18 such as a GUI or an external operation switch. The viewing distance 74 to the image display device 36 is estimated and stored in the EEPROM 33 as the viewing distance 74 data.

Next, ambient brightness information in the viewing environment is captured.
FIG. 4 is a diagram illustrating a state in which ambient brightness information is captured in a viewing environment.
First, the direction of the image display device 36 is imaged from the viewing position. At this time, it is desirable for the user 72 to pick up an image by including it to some extent up to the periphery of the image display device 36 that is the subject. With respect to this, an image frame alignment guide serving as a guide for displaying an image being captured on the image display unit 15 such as an LCD panel mounted on the main body of the image recording / reproducing apparatus 1 and aligning the outer shape of the external image display device 36 within the screen. 81 is superimposed and displayed as a GUI. This makes it possible to guide the user to a standard image frame for capturing ambient brightness information. The image frame alignment guide 81 determines its size from a variable α which is a value obtained by dividing a viewing distance described later by the screen size.

  At this time, in the image recording / reproducing apparatus 1, the position of the iris 5 as a result of adjusting the exposure level using the automatic exposure function in the camera signal processing unit 9, the speed of the electronic shutter of the image sensor 6, and the camera signal processing unit 9 The microcomputer 17 recognizes the ambient brightness level from the level information of the gain adjusting units 48 and 54.

  The microcomputer 17 stores this information as data in the EEPROM 33 by an operation for instructing the viewing environment information capturing operation using the user interface 18 such as a GUI or an external operation switch. At this time, correction processing based on viewing environment information can be performed based on viewing distance and / or surrounding brightness information as viewing environment information.

  As described above, the user 72 can easily store the viewing environment information in the image recording / reproducing apparatus 1 by the function and operation of the image recording / reproducing apparatus 1, and the information stored in the EEPROM 33 in FIG. It can be used as an image processing correction parameter in the camera signal processing unit 9 during actual photographing and reproduction.

Next, a process for acquiring and storing the display performance information of the image display device 36 described above will be described.
FIG. 5 is a conceptual diagram for explaining a process for acquiring and storing display performance information of the image display device 36.
First, the image recording / reproducing apparatus 1 acquires display performance information of the image display device 36 from the image display device 36. That is, the image display device 36 and the image recording / reproducing device 1 are connected by a communication line, and the image recording / reproducing device 1 acquires display performance information data of the image display device 36 by communication between them. The acquired data is stored and stored in the EEPROM 33 by the microcomputer 7.

  The data acquired by this operation includes information such as individual identification information of the image display device 36, the vertical / horizontal size of the screen, γ characteristics, white point chromaticity, RGB chromaticity, and corresponding image format. The data in the display device information EEPROM 39 in the image display device 36 is EDID information 91 compliant with EDID (Extended Display Identification Data) of VESA (Video Electronics Standards Association) standard.

  Apart from acquiring the image display performance information from the image display device 36, as indicated by 95, the image display stored on the server 94 of the Internet 93 as the display performance information acquisition means of the other image display devices 36. It is also possible to acquire data of individual identification information of the apparatus and image display capability information using a communication means. Alternatively, the built-in microcomputer 17 may read and acquire the individual identification information and display performance information data of the image display device stored in a removable recording medium such as the flash memory 92.

As described above, the display performance information data acquired by the microcomputer 7 and stored in the EEPROM 33 is used as an image processing correction parameter in the camera signal processing unit 9 at the time of actual shooting or playback, as with the viewing environment information described above. It becomes possible.
In addition, the order of acquisition of viewing environment information and display performance information may be either first.

Next, a process for correcting the image quality of an image using the above-described viewing environment information and display performance information together at the time of imaging, recording, or reproduction will be described.
Usually, the camera signal processing unit 9 (see FIG. 1) automatically performs image quality correction of an image using the viewing environment information and the display performance information described above. It is also possible for the user 72 to set manually through the user interface 18.

Hereinafter, a processing procedure at the time of image signal processing correction in the viewing environment will be described.
First, the microcomputer 17 corrects the parameter setting of each process of the camera signal processing unit 9 based on the display performance information of the image display device 36. The correction parameter items include items such as frequency characteristics, the degree of edge enhancement, luminance, hue, saturation, gradation characteristics, and light source color temperature.

The processing of the correction parameter item is performed by the following units.
That is, in order to correct the frequency characteristics and the degree of contour enhancement, the microcomputer 17 performs the correction by correcting the gain of the high frequency component extraction filter 53.
The hue and saturation are corrected by the microcomputer 17 converting the angle and level of the color difference signals (RY, BY) indicating the color temperature in the hue (HUE) / gain matrix unit 61. Execute.

Further, the correction of the gradation characteristics is executed by the microcomputer 17 changing the gamma conversion curve of the gamma conversion (1 / γ) unit 50.
As a means for adjusting the brightness, the microcomputer 17 executes the aperture control of the iris 5, the speed control of the electronic shutter of the image sensor 6, and the gain adjustment of the gain adjusting units 48 and 54. At this time, the reference brightness setting for automatic exposure is corrected.

Further, the correction of the color temperature is executed by the microcomputer 17 performing white balance adjustment in the white balance unit 49.
With this operation, image quality correction is performed in accordance with the viewing environment such as a standard viewing distance and ambient brightness.

Next, a process for further correcting the parameter setting of each process of the camera signal processing unit 9 based on the viewing environment information described above will be described.
The microcomputer 17 includes three pieces of information including the viewing distance and ambient brightness obtained by the above-described viewing environment information obtaining process and the screen size obtained by the obtaining process for obtaining display performance information and the current parameter setting value. Is used to calculate the correction amount of each process of the camera signal processing unit 9 and automatically reset the parameters. This correction algorithm will be described below.

First, examples of the implications of the effects of the three elements of viewing distance, ambient brightness, and screen size on the viewing image will be described individually.
For example, when the viewing distance is long, the screen size in the field of view becomes relatively small for the viewer, and the details of the display image are difficult to see. In addition, the influence of ambient brightness increases.

In addition, when the viewing distance is short, the screen size in the field of view becomes relatively large for the viewer, and the details of the display image are sufficiently visible. Therefore, the image looks unnatural when the contour emphasis processing is performed. In addition, the influence of ambient brightness is reduced.
When the surroundings are bright, the display image appears relatively dark to the viewer. Also, depending on the dynamic range of the eyes, the gradation of the dark part of the display image cannot be recognized.

In addition, when the surroundings are dark, the display image looks relatively bright for the viewer. In extreme cases it feels dazzling. Further, depending on the dynamic range of the eyes, the gradation of the bright part of the display image cannot be recognized.
Further, when the screen size is small, it is difficult for viewers to see the details of the display image and sharpness is insufficient. In addition, the influence of ambient brightness increases.
In addition, when the screen size is large, the detail of the display image is sufficiently visible to the viewer, so that the image looks unnatural when the contour emphasis processing is performed. Further, it can be assumed that the degree of influence of ambient brightness becomes small.

The correspondence between the above-described influence on the viewing image, the correction item, and the processing direction is executed as follows.
First, the effect that it is difficult to see the details is dealt with by performing image processing in a direction to increase the level of the high-frequency component of the image signal and performing edge enhancement.
Further, the effect of contour enhancement when the detail state can be sufficiently recognized is dealt with by correcting the level of the high frequency component of the image signal so as to be as close to flat frequency characteristics as possible.

Furthermore, the effect that the ambient brightness level is high and the influence level is large can be dealt with by processing in the direction of increasing the luminance level of the output image signal.
In addition, the influence of the low ambient brightness level and the large degree of influence is dealt with by processing in the direction of decreasing the luminance level of the output image signal.

Further, for the effect that it is difficult to recognize the gradation of the bright part, the curve near the low level of the gamma conversion (1 / γ) processing is changed from the curve 111 before correction shown in FIG. 10 to the curve 112 after correction. Respond by correcting.
Further, for the influence that the dark gradation is difficult to recognize, the curve near the low level of the gamma conversion (1 / γ) processing is corrected from the curve 102 before correction shown in FIG. 9 toward the curve 101 after correction. Think of it as a correspondence relationship.

When these corrections are performed by the camera signal processing unit 9, the detail correction is performed by the microcomputer 17 by controlling the output gain of the high frequency component extraction filter 53.
The microcomputer 17 executes the correction of the brightness level by changing the reference level of the automatic exposure control in the detection unit 59.
Further, the gradation correction is performed by the microcomputer 17 by performing a curve correction of the gamma conversion characteristic in the gamma conversion (1 / γ) processing unit 50.

  Here, the meaning of the effect on the viewing image is that the screen size is large = the viewing distance is short, the screen size is small = the viewing distance is long, and based on this, α = viewing distance / screen size The variable α is set. This variable α represents two meanings, that is, a relative screen size in the viewer's field of view and an influence level of ambient brightness.

FIG. 11 is a diagram showing the influence of ambient brightness according to α = viewing distance / screen size.
A reference value d is set for this variable α. Generally, it is said that the optimum viewing distance is several times the screen size in the vertical direction, and is set under a condition that matches this condition.
Here, when α = d, the screen size in the viewer's field of view is standard. At this time, since the viewing distance is standard with respect to the size of the screen, the influence of ambient brightness is standard.

Further, when α> d, the size of the screen in the field of view is relatively small, and it becomes difficult to see the details of the image, so the influence of ambient brightness is large.
On the contrary, when α <d, the size of the screen in the field of view is relatively large, and the details of the display image can be recognized sufficiently, so that the influence of ambient brightness is small.

In addition, a variable β = ambient brightness × α is set.
This variable β represents the direction of correction for the actual ambient brightness and the degree of correction required. The value of the variable β when α = d at standard brightness is used as a reference value, and this is set as r.

  First, when β = r, the relationship between the influence level and the brightness is standard. In addition, when β> r, it is relatively bright considering the degree of influence. On the other hand, when β <r, it is relatively dark considering the degree of influence. Based on the above, FIG. 6 shows a flowchart as an example of the correction process for the viewing environment information.

In FIG. 6, first, when the correction process is started (step S1), it is determined whether or not α> d (step S2). When α> d in step S2, the high frequency component is emphasized (step S3).
When α> d is not satisfied in step S2 and when the high frequency component of step S3 is emphasized, it is determined whether β = r (step S4). When β <r in step S4, the luminance level is increased to obtain a curve in which the dark part of the gamma conversion characteristic γ is raised (step S5). When β> r in step S4, the luminance level is lowered to a curve with the bright part of the gamma conversion characteristic γ dropped (step S6). Then, the correction process ends (step S7).

FIG. 7 is a diagram showing an example of the degree of emphasizing the high frequency component with respect to the level of α, that is, the level of enhancement correction of the high frequency component for α. FIG. 7 shows a case where high frequency components are emphasized when α> d in step S3 of FIG.
FIG. 8 is a diagram showing an example of the relationship of luminance level correction with respect to the level of β. FIG. 8 shows a case in which the brightness level is increased when β <r in step S5 in FIG. 6 to form a curve with a dark portion of the gamma conversion characteristic γ, and the brightness level when β> r in step S6. This shows a case where the curve is made by lowering the bright portion of the gamma conversion characteristic γ.

  As shown in the flowchart of FIG. 6, if β> r in step S6, the brightness level is lowered, that is, if the automatic exposure reference level is lowered in the camera, the dark portion of the image is crushed and the gradation cannot be determined. there is a possibility. For this reason, in addition to the correction of the luminance level, correction is performed in a direction in which the dark part of the curve of the gamma conversion characteristic of the gamma conversion (1 / γ) processing unit 50 is raised. This is shown in FIG.

  Conversely, if the brightness level is increased when β <r in step S5, that is, if the automatic exposure reference level is increased in the camera, the bright part of the image may be crushed and the gradation may not be determined. For this reason, in addition to the correction of the luminance level, correction is performed in a direction in which the bright part of the curve of the gamma conversion characteristic of the gamma conversion (1 / γ) processing unit 50 is dropped. This is shown in FIG.

Finally, the distinction of processing by the image signal source will be described.
The image recording / playback apparatus 1 can process not only the input signal from the image sensor 6 but also the playback signal from the recording medium 28 and the image signal from the external stream by switching the input signal of the camera signal processing unit 9. ing.

That is, the host microcomputer 17 selects an input signal of the camera signal processing unit 9 according to an operation mode described below, recognizes a difference in image quality between the selected operation modes, and adjusts the degree of correction. It is possible.
First, a mode for outputting an image of a camera to an external image display device, second, a mode for outputting an image to the external image processing device while recording the image of the camera on a recording medium, and third, a mode from the recording medium There are four operation modes: a mode for outputting a reproduced image to an external image display device, and a fourth mode for outputting an input image from an external stream to an external image display device.

  In general, when DCT (discreet cosine transformation) or the like is used in compression / decompression processing for recording and transmission, frequency characteristics may be deteriorated due to block noise or the like. For this reason, when the camera image is output to the external image display device 36 without going through the recording medium, the camera image is temporarily compressed and recorded on the recording medium 28, the reproduction signal is expanded, and the external image display device 36 is expanded. In the case of the output to, it may be necessary to change the gain of the high-frequency component extraction filter 53.

In the scene of the first operation mode, correction may be performed as described in the image signal processing correction processing in the viewing environment described above.
In the second operation mode, it is assumed that the image recorded on the recording medium 28 is reproduced and viewed later, so that the corresponding items are corrected in advance in anticipation of deterioration of the frequency correction due to the compression processing. You may keep it.

In the scene of the third operation mode, if the correction has been performed at the time of the second operation mode, no correction is necessary. If the recording medium 28 is detachable and is not recorded by itself, correction may be performed.
Further, in the scene of the fourth operation mode, it can be considered similarly to the third operation mode. That is, the luminance adjustment for the input signals other than the image sensor 6 is performed by gain adjustment for the gain adjustment units 48 and 54 in the camera signal processing unit 9.
By performing the correction processing as described above, it is possible to set the image quality that is actually preferable including the display performance of the image display device 36 and the viewing environment of the user.

  According to the embodiment of the present invention, in addition to the correction of the image processing based on the display performance information of the image display device 36, the user can acquire the viewing environment information through the camera unit with a simple operation, and the image recording / reproducing device. 1 can be stored. Then, by automatically adjusting the image signal processing parameter settings based on the information on the viewing environment, it is possible to eliminate the need for image quality correction on the image display device 36 side. It is possible to display an image with a suitable image quality setting including the environment.

  It goes without saying that the configuration can be changed as appropriate within the scope of the present invention, not limited to the embodiment described above.

1 is a system configuration diagram showing an embodiment of the present invention. It is a figure which shows the block structural example of a camera signal processing part. It is a figure which shows the state which takes in the information of viewing environment to an image recording / reproducing apparatus. It is a figure which shows the mode of taking in the surrounding brightness information in viewing environment. It is a conceptual diagram which acquires and memorize | stores the display performance information of an image display apparatus. It is a flowchart which shows the example of the correction process with respect to the information of viewing environment. It is a figure which shows the example of the relationship of the degree of emphasis of the high frequency component with respect to the level of (alpha). It is a figure which shows the example of the relationship of the grade of the correction | amendment of a luminance level with respect to the level of (beta). It is a figure which shows the correction example 1 of the characteristic of 1 / γ. It is a figure which shows the example 2 of correction | amendment of the characteristic of 1 / gamma. It is a figure which shows the influence degree of the surrounding brightness according to (alpha) = viewing distance / screen size.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image recording / reproducing apparatus, 2 ... Optical system, 3 ... Zoom lens, 4 ... Focus lens, 5 ... Iris, 6 ... Image sensor, 7 ... Analog front end part, 8 ... A / D converter part, 9 ... Camera signal Processing unit, 10 ... Baseband signal processing unit, 11, 13 ... Pixel number conversion unit, 12 ... GUI generation / superimposition unit, 14 ... OSD generation / superimposition unit, 15 ... Image display unit, 17 ... Microcomputer, 18 ... User interface, 19, 20, 21, 22 ... optical system driver / actuator, 23 ... driver, 25, 26 ... code amount compression / expansion unit, 28 ... recording medium 1, 29 ... external stream interface, 30 ... output format conversion unit, 31 ... Image signal interface unit 32... Display device information interface unit 33 33 EEPROM 34 Recording medium unit 2 35 ... Communication means, 36 ... External image display device, 37 ... Image signal interface unit, 38 ... Display device information interface unit, 39 ... EEPROM, 40 ... Timing generator

Claims (8)

Image signal processing performed by the image signal processing unit on the image information captured by the imaging unit, and the image information subjected to the image signal processing displayed on the display unit and recorded on the recording medium by the recording unit In the device
A communication means for communicating with the image display device in order to display the image information subjected to the image signal processing on an external image display device;
Acquisition means for acquiring information relating to image display performance of the image display device;
A first image quality correction adapted to the display characteristics of the image display device is performed by correcting the parameters of the image signal processing by the image signal processing device according to the image display performance of the image display device acquired by the acquisition device. Correction means;
Measuring means for measuring data relating to the viewing environment of the image display device by the imaging means;
Second correction means for performing image quality correction suitable for the viewing environment by further correcting parameters of the image signal processing by the image signal processing means based on the data relating to the viewing environment;
An image signal processing apparatus comprising:   Information relating to the image display performance of the image display device is acquired from the image display device via the communication means, acquired from a server on the network via the communication means, or other removable recording medium The image signal processing apparatus according to claim 1, wherein the image signal processing apparatus is acquired from   The image signal processing apparatus according to claim 1, wherein the information related to the image display performance of the image display apparatus includes individual identification information of the image display apparatus and various functional information included in the image display apparatus.   The image signal processing apparatus according to claim 1, wherein the data relating to the viewing environment of the image display device includes brightness of the viewing environment and / or viewing distance.   The image signal processing apparatus according to claim 1, further comprising storage means for storing information relating to image display performance of the image display apparatus.   The image quality correction of the viewing environment by the second correction unit performs correction of a parameter that emphasizes the high frequency component of the image signal processing by the image signal processing unit according to the viewing distance, and / or the brightness of the viewing environment. 5. The image signal processing apparatus according to claim 4, wherein a parameter of a luminance level characteristic of the image signal processing by the image signal processing means is corrected according to the function. In an image signal processing method for performing image signal processing on captured image information, displaying the image information subjected to the image signal processing, and recording the information on a recording medium.
A communication step of communicating with the image display device in order to display the image information subjected to the image signal processing on an external image display device;
An acquisition step of acquiring information relating to the image display performance of the image display device;
A first correction step of performing image quality correction suitable for the display characteristics of the image display device by correcting the parameters of the image signal processing according to the acquired image display performance of the image display device;
A measurement step of measuring data relating to the viewing environment of the image display device by the imaging;
A second correction step of performing image quality correction suitable for the viewing environment by further correcting the parameters of the image signal processing based on the data relating to the viewing environment;
An image signal processing method comprising: Image signal processing performed by the image signal processing unit on the image information captured by the imaging unit, and the image information subjected to the image signal processing displayed on the display unit and recorded on the recording medium by the recording unit In an image signal processing system having a device and an external image display device that displays the image information connected to the image display device and subjected to the image signal processing,
The image signal processing apparatus is
A communication means for communicating with the image display device in order to display the image information subjected to the image signal processing on an external image display device;
Acquisition means for acquiring information relating to image display performance of the image display device;
A first image quality correction adapted to the display characteristics of the image display device is performed by correcting the parameters of the image signal processing by the image signal processing device according to the image display performance of the image display device acquired by the acquisition device. Correction means;
Measuring means for measuring data relating to the viewing environment of the image display device by the imaging means;
Second correction means for performing image quality correction suitable for the viewing environment by further correcting the parameters of the image signal processing by the image signal processing means based on the data relating to the viewing environment,
The external image display device
An image signal processing system comprising storage means for storing information relating to image display performance of the image display device.

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