JP2009171178A - Signal generator, test pattern, and evaluation method of video apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and surely examine degradation of picture quality and noise caused by encoding process and decoding process such as MPEG2, relating to a signal generator, test pattern, and evaluation method of video apparatus. <P>SOLUTION: The same still image is displayed in regions AR1-AR4 formed by dividing a display screen in vertical direction or horizontal direction. The still image is scrolled in horizontal direction or vertical direction at a different scrolling speed for each of the regions AR1-AR4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a signal generator, a test pattern, and a video device evaluation method, and can be used for confirmation of encoding processing and decoding processing of, for example, MPEG (Moving Picture Experts Group) 2. The present invention displays the same still image in each area formed by dividing the display screen in the vertical direction or the horizontal direction, and scrolls in the horizontal direction or the vertical direction at different scroll speeds for each area, so that MPEG2 or the like is displayed. It is possible to easily and reliably confirm image quality degradation, noise, and the like due to the encoding process and decoding process.

  In recent years, video equipment has become MPEG2, H264. Video signals are transmitted by various encoding processes and decoding processes such as AVC (Advanced Video Coding). In these encoding processes, a difference signal (prediction error signal) is generated between successive frames by applying a motion compensation method, and this difference signal is sequentially converted into an orthogonal transform process, a quantization process, and a variable length encoding process. To do. In these encoding processes, these processes are executed in units of macroblocks. Also, for example, the TM5 method is applied to vary the quantization scale in each macroblock, and the video signal is encoded at a desired bit rate.

  Conventionally, these video devices have been examined various characteristics by inputting test signals such as color bars and gray scales from a signal generator. In the signal generator, for example, as disclosed in Japanese Patent Application Laid-Open No. 2007-267284, various test signals are generated by sequentially reading test signal image data held in a memory.

By the way, in the encoding process such as MPEG2, if the code amount allocation to each macroblock is not properly executed, for example, the macroblock on the raster scanning end side is compared with the macroblock on the raster scanning end side. The image quality is significantly deteriorated, and the block noise further increases. It would be convenient if it was possible to easily and reliably confirm such image quality degradation, noise, and the like due to such encoding processing and decoding processing.
JP 2007-267284 A

  The present invention has been made in consideration of the above points, and is a signal generator, test pattern, and video equipment capable of easily and reliably confirming MPEG2 and other encoding processing, image quality degradation due to decoding processing, noise, and the like. I would like to propose an evaluation method.

  In order to solve the above problems, the invention of claim 1 is applied to a signal generator that outputs a test signal, wherein the test signal is a signal for displaying a test pattern, and the test pattern is in a vertical direction or a horizontal direction. The same still image is displayed in each region formed by dividing the display screen in the direction, and the same still image is scrolled in the horizontal direction or the vertical direction at different scroll speeds for each region. .

  According to a second aspect of the present invention, in the configuration of the first aspect, the scroll speed of each region is set to be higher in a region farther from the raster scanning start end side.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, the scroll speed of each of the regions is varied according to a user instruction.

  According to a fourth aspect of the present invention, in the configuration of the first, second, or third aspect, the scroll direction of each region is switched in accordance with a user instruction.

  According to a fifth aspect of the present invention, the test signal output from the signal generator according to the first, second, third, or fourth aspect is applied to a video device evaluation method. Process and display, and evaluate the processing of the test signal in the video equipment by visual observation of the test pattern.

  The invention of claim 6 is applied to a test pattern for evaluation of video equipment, and displays the same still image in each area formed by dividing the display screen in the vertical direction or the horizontal direction. The same still image scrolls horizontally or vertically at different scroll speeds.

  The invention of claim 7 is applied to a video device evaluation method, wherein the video signal of the test pattern according to claim 6 is processed and displayed by the video device, and the video is obtained by visual observation of the test pattern. Evaluate the processing of the test signal in the instrument.

  According to the configuration of the first aspect, it is possible to easily and reliably confirm image quality degradation, noise, and the like, for example, by comparing the raster scan start end side and end end side. Accordingly, it is possible to determine whether the amount of code assigned to each macroblock is appropriate or inappropriate.

  According to the second aspect of the present invention, when the generated code amount of each macroblock is rate-controlled by raster scanning or alternate scanning, image quality deterioration, noise, etc. can be confirmed more appropriately.

  According to the third aspect of the present invention, it is possible to check the image quality deterioration, noise, and the like in various types of moving images more appropriately by varying the scroll speed of each region.

  According to the fourth aspect of the present invention, the scroll direction of each region can be set in various ways, and image quality deterioration, noise, etc. in various types of moving images can be confirmed more appropriately.

  According to the configuration of the fifth, sixth, or seventh aspect, it is possible to easily and reliably determine image quality deterioration, noise, and the like by comparing the raster scanning start end side and the end end side. Accordingly, it is possible to determine whether the amount of code assigned to each macroblock is appropriate or inappropriate.

  According to the present invention, it is possible to easily and reliably confirm image quality degradation, noise, and the like due to encoding processing and decoding processing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 2 is a block diagram showing a signal generator according to Embodiment 1 of the present invention. The signal generator 1 outputs video signals of various test patterns such as color bars and gray scales. In this embodiment, the signal generator is processed and displayed on the video device to be evaluated, and the image quality and noise in each part of the display image are evaluated by visual observation, thereby evaluating the video signal processing in this video device. To do. Specifically, for example, when the video device is an MPEG2 encoding device, the video signal is encoded by the encoding device, then decoded by the decoding device, and displayed. Evaluate the device.

  In the signal generator 1, the test signal memory 2 stores and holds test signal image data of various test signals, and outputs the test signal image data held under the control of the controller 3.

  The test signal output circuit 4 switches the output format under the control of the controller 3, processes the test signal image data output from the test signal memory 2, and outputs various test signals S1. Here, the output format of the test signal S1 includes composite, component analog video signal output, color signal video signal output, digital signal video signal output, and the like.

  The controller 3 controls the operation of the test signal memory 2 and the test signal output circuit 4 in response to the operation of the operator provided in the signal generator. That is, when the user instructs the test signal S1 to be output by a normal color bar, gray scale, or the like, the controller 3 reads the corresponding test signal image data from the test signal memory 2 and inputs it to the test signal output circuit 4. To output a test signal S1 based on these color bars and gray scales. When the user instructs to scroll these test signals S1, the read address from the test signal memory 2 is changed for each field or for each frame, and the corresponding test signal image data is sequentially transferred from the test signal memory 2. This is read out and input to the test signal output circuit 4, thereby outputting a test signal S 1 of a scroll image using these color bars, gray scales, and the like.

  On the other hand, when the user instructs split scroll display, the controller 3 controls the operation of each unit and outputs a split scroll test signal S1. Here, the test signal for split scroll display displays the same still image in areas AR1 to AR4 formed by dividing one screen into the same width in the vertical direction as shown in FIG. The test signals are used to scroll still images in the areas AR1 to AR4 at different scroll speeds v1 to v4 in the areas AR1 to AR4. In FIG. 1, W is white, Y is yellow, C is cyan, G is green, M is magenta, R is red, and B is blue. In addition to the color bar, this same still image applies grayscale, an image that gradually changes in luminance and / or hue in a ramp function in the horizontal direction, various patterns for checking the horizontal resolution, natural images, etc. can do.

  The controller 3 displays the same still image in these areas AR1 to AR4 by repeatedly reading out the same test signal image data from the test signal memory 2 in each of the areas AR1 to AR4. In each of the areas AR1 to AR4, the read address from the test signal memory 2 is changed at different speeds for each field or for each frame, and each of the areas AR1 to AR4 is scrolled at different scroll speeds v1 to v4.

  In this embodiment, in the default state, the scroll speed v1 of the first area AR1 that is closest to the raster scanning start end is set to 0, so that the first area AR1 is not scrolled. . Further, the scroll speeds v2 to v4 from right to left are gradually increased as the distance from the first area AR1 increases. The scroll speed is 30 pixels / second or more.

  When the user designates an area and instructs to switch the scroll direction, the controller 3 reverses the read address change direction in the corresponding area AR1 to AR4, thereby switching the scroll direction for each of the areas AR1 to AR4.

  When the user designates the area and instructs to change the scrolling speed, the controller 3 changes the read address changing speed in the corresponding area AR1 to AR4 in response to the user operation, and thereby, for each area AR1 to AR4. Variable scroll speed.

(2) Operation of Embodiment In the above configuration, in the signal generator 1, after the test signal image data stored in the test signal memory 2 is read in response to a user operation, the test signal output circuit 4 is converted into a predetermined format, whereby various test signals S1 such as color bars and gray scales are output for testing the video equipment.

  When the user instructs split scroll display, the same still image is displayed in areas AR1 to AR4 formed by dividing one screen in the vertical direction, and scrolls are performed at different scroll speeds v1 to v4 in the areas AR1 to AR4. The output is switched to the divided scroll test signal S1.

  Here, in the divided scroll test signal S1, the same still image is displayed in the areas AR1 to AR4 formed by dividing the screen in the vertical direction, and each of the areas AR1 to AR4 is scrolled at different scroll speeds v1 to v4. Therefore, the image quality and noise in each part of each region can be confirmed by comparison with the corresponding display in the other region.

  That is, for example, if this divided scroll is executed with the color bar, for example, at a specific time, a specific color is displayed at the same time on the left end of the uppermost area AR1 and the right end of the lowermost area AR4. As a result, the image quality and noise can be confirmed for this specific color. Further, if the time points are different, the specific colors displayed at the left end and the right end are different, and the image quality and noise can be similarly confirmed with respect to the different colors.

  As a result, in this embodiment, it is possible to easily and reliably confirm the image quality degradation, noise, and the like due to the encoding process and the decoding process, and confirm whether or not the code amount is appropriately allocated to each macroblock. be able to.

  In this embodiment, in the default state, the scroll speed of each of the areas AR1 to AR4 is set to increase toward the raster scanning end side. As a result, it is possible to more appropriately confirm image quality degradation, noise, and the like due to encoding processing and decoding processing such as MPEG2.

  That is, in encoding processing and decoding processing such as MPEG2, macroblocks are sequentially processed in raster scanning order or alternate scanning order, and when the code amount allocation to the macroblocks is inappropriate, these scanning orders are processed. In the macroblock on the scanning end side in FIG. 5, the image quality is remarkably deteriorated, and further noise increases. In TM5 or the like used for rate control, the generated code amount is detected for each macroblock, and the allocated code amount to the macroblock to be processed subsequently is calculated from this generated code amount.

  As a result, in processes such as MPEG2, when the prediction error signal increases in the second half of scanning in the raster scanning order or the alternate scanning order, assignment of the code amount to the macroblock is often inappropriate.

  On the other hand, if the scroll speed of each of the areas AR1 to AR4 is set to increase toward the raster scanning end side, the prediction error signal becomes as if the second half of scanning in the raster scanning order or the alternate scanning order. In this way, it is possible to simulate a moving image with an increase in image quality, thereby further confirming image quality degradation, noise, and the like due to encoding processing such as MPEG2 and decoding processing.

  Further, in this embodiment, the scroll speed in each of the areas AR1 to AR4 is varied and the scroll direction is switched according to a user instruction. As a result, various moving images in the natural world can be simulated, and image quality degradation, noise, etc. due to encoding and decoding processing such as MPEG2 can be confirmed more appropriately.

(3) Effects of the embodiment According to the above configuration, the same still image is displayed in each region formed by dividing the display screen in the vertical direction, and this still image is horizontally displayed at a different scroll speed for each region. By scrolling, it is possible to easily and surely confirm image quality degradation, noise, and the like due to encoding processing such as MPEG2 and decoding processing.

  In addition, by setting the scroll speed higher in the area farther from the raster scan start end side, when controlling the generated code amount of each macroblock by raster scan or alternate scan, image quality degradation, Etc. can be confirmed.

  In addition, by changing the scroll speed of each area according to the user's instruction, and further by switching the scroll direction of each area according to the user's instruction, it is possible to check image quality deterioration, noise, etc. more appropriately. .

  In the above-described embodiment, the case where the screen is divided in the vertical direction and the respective areas are scrolled in the horizontal direction has been described. However, the present invention is not limited to this, and the screen is divided in the horizontal direction to make the respective areas in the vertical direction. You may make it scroll to.

  In the above-described embodiment, the case where each area is the same width and one screen is divided into four has been described. However, the present invention is not limited to this, and the number of divisions and the width of each area can be variously set as necessary. Can do.

  In the above-described embodiment, the case where the image data is read from the memory and the test signal is output has been described. However, the present invention is not limited to this, and the video signal recorded on the optical disc, the memory card, etc. is reproduced to perform the test. The present invention can be widely applied to the case of outputting a signal.

  In the above-described embodiments, the case where the encoding device is evaluated has been described. However, the present invention is not limited to this, and the present invention can be widely applied to the evaluation of the decoding device and the evaluation of various video devices.

  The present invention relates to a signal generator, and can be used for confirmation of encoding processing and decoding processing of, for example, MPEG2.

It is a top view with which it uses for description of the test signal of the division | segmentation scroll which concerns on Example 1 of this invention. It is a block diagram which shows the signal generator which concerns on Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Signal generator, 2 ... Test signal memory, 3 ... Controller, 4 ... Test signal output circuit

Claims (7)

In a signal generator that outputs a test signal,
The test signal is
A signal that displays a test pattern,
The test pattern is
Display the same still image in each area formed by dividing the display screen vertically or horizontally,
A signal generation device, characterized in that it is a test pattern for scrolling the same still image in a horizontal direction or a vertical direction at a different scroll speed for each region. The signal generator according to claim 1, wherein the scroll speed of each region is set to be higher in a region farther from the raster scanning start end side. The signal generation device according to claim 1, wherein a scroll speed of each of the regions is varied in accordance with a user instruction. The signal generation device according to claim 1, wherein the scroll direction of each of the regions is switched according to a user instruction. The test signal output from the signal generator according to claim 1, claim 2, claim 3, or claim 4 is processed and displayed by a video device, and the test pattern is visually observed in the video device. An evaluation method for video equipment, characterized by evaluating processing of the test signal. In the test pattern used for evaluation of video equipment,
Display the same still image in each area formed by dividing the display screen vertically or horizontally,
A test pattern in which the same still image is scrolled in a horizontal direction or a vertical direction at a different scrolling speed for each region. A video signal of the test pattern according to claim 6 is processed and displayed by the video equipment, and the processing of the test signal in the video equipment is evaluated by visual observation of the test pattern. Evaluation methods.

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