JPH06178329A - Picture test pattern generation circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to generate a test pattern for an image test pattern generation circuit, which can confirm the basic operation of the image encoding device without connecting to other devices. [Structure] A pattern is output by a counter output of an image encoding device.
In the image test pattern generation circuit for reading image information from the image generation ROM, a horizontal direction control ROM (4) for generating one pattern generation ROM read signal for the counter output corresponding to a fixed number of pixels, Vertical control ROM that generates one pattern generation ROM read signal for counter output corresponding to a certain number of scanning lines
(5), which uses or switches one of the output of the horizontal direction control ROM (4) and the output of the vertical direction control ROM (5) to switch the test pattern signal from the pattern generation ROM (7). A test pattern generating circuit for image is configured to generate a test pattern by sequentially reading out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image test pattern generation circuit in an image coding apparatus. For various highly functionalized devices in recent years, it is desired that the basic operation of the device can be confirmed without connection to an external device.
Therefore, the image coding apparatus also has a built-in function for generating a test pattern such as a color bar. However, when data for one image (that is, one frame) is provided, one frame worth of data is stored. A memory circuit having a capacity of 1 is required, and power consumption increases with an increase in circuit scale, which has a great influence on the system.

For this reason, a conventional test pattern generating circuit for holding data of only a part of an image has been conventionally provided.

[0003]

2. Description of the Related Art FIG. 7 shows a conventional configuration example. (a) is a block configuration diagram in the case of vertical stripes, and (b) is a block configuration diagram in the case of horizontal stripes. In the figure, 1 is a PEL counter corresponding to each pixel on the screen, 2 is a line counter corresponding to each horizontal scanning line, 8 is a pattern generation ROM, and a predetermined vertical stripe pattern is produced by the output of the PEL counter 1. (For example, red, green, etc.), 9 is a pattern generation ROM, which generates a predetermined horizontal stripe pattern by the output of the line counter 2.

By adopting such a configuration, the vertical data represented by the vertical stripes, the horizontal data represented by the horizontal stripes, the moving picture image coding apparatus, and the moving picture (pseudo) pattern. If so, temporary debugging (maintenance inspection, etc.) can be performed without connecting to external video equipment. However, in this case, only a fixed pattern could be generated. For example, in FIG.
In the case of (a), the PEL counter output is 1, 2, 3, 4, 5
The output of the pattern generation ROM 8 changes to a, b, c, d, and e as it progresses to, and the same pattern as the PEL counter output proceeds to 6, 7, 8, 9, and 10.
It becomes a fixed pattern that changes as c, d, and e, and becomes the same vertical stripe regardless of the size of the screen.

[0005]

Therefore, when it is used for testing a screen having a different number of pixels, there is a drawback that it is inconvenient to use. According to the present invention, a counter for knowing a screen position, which is indispensable at the time of image encoding processing, and an R for changing data.
The object is to configure a circuit that generates vertical and horizontal moving images (pseudo) only with the OM.

[0006]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 11 is a horizontal direction control unit, 12 is a vertical direction control unit for grasping the screen position,
Reference numeral 6 is a selector for selecting either the output of the horizontal direction control unit 11 or the output of the vertical direction control unit 12, and 7 is a pattern generation ROM having image data.
The pattern generation ROM 7 is hereinafter referred to as a conversion ROM in order to distinguish it from the conventional pattern generation ROMs 8 and 9.

By giving the output of the counter 1 or the counter 2 selected by the selector 6 as an address of the pattern generation ROM 7, it is possible to realize a vertical stripe, a horizontal stripe and a pseudo moving picture test pattern in a designated portion of the screen.

[0008]

In the present invention, when the selector 6 selects the output of the horizontal direction control section ROM 11 as shown in FIG.
The output of the horizontal direction control unit ROM 11 sequentially designates the address of the conversion ROM 7 for every m outputs of the L counter, and the test pattern signal is output from the address. As a result, m
A pixel wide vertical stripe is obtained on the screen. When the selector 6 selects the output of the vertical direction control unit ROM 12, the vertical direction control unit R is output for every n line counter outputs.
The output of the OM 12 sequentially designates the address of the conversion ROM 7, and the test pattern signal is output from the address.
As a result, a horizontal stripe of n line width is obtained on the screen.

Further, the selector 6 controls the horizontal control unit RO.
A pattern in which vertical stripes and horizontal stripes are mixed can be obtained by switching the output of M11 and the output of the vertical direction control unit ROM12 at an appropriate cycle. Furthermore, a pseudo moving image can be obtained by setting the number of pixels in the horizontal direction not to be an integer multiple of n. Similarly, a pseudo moving image can also be obtained by setting the number of horizontal scanning lines not to be an integral multiple of m. In this case, it is expected that the change will be slower.

[0010]

FIG. 2 is a block diagram of an embodiment of the present invention, showing a case where a circuit relating to the present invention is built in an image coding apparatus. The image coding apparatus incorporates a PEL counter and a line counter in order to know the horizontal direction and the vertical direction of the screen to grasp the screen position. This PEL
A counter, a line counter, and a vertical, horizontal, and moving image (pseudo) test pattern are created using only one line of data. In the figure, 1 is a PEL counter, which horizontally scans one pixel at a time by a clock pulse not shown in the figure, and 2 is a line counter, which sequentially moves one horizontal scan line after one horizontal scan is completed. And a circuit originally built in the image coding apparatus, 4
Is a control ROM for the horizontal direction, which outputs one pulse for every m output pulses of the PEL counter 1, 5 is a control ROM for the vertical direction, one pulse for every n output pulses of the line counter 2 Is output. Others are first
It is the same as the case of the figure.

In the following, how to generate a test pattern for a system having different screen sizes will be described with respect to embodiments in which vertical stripes occur, horizontal stripes occur, and pseudo moving images occur. FIG. 3 is an explanatory diagram of the occurrence of vertical stripes. In this case, it is assumed that the selector 6 is switched to the horizontal control ROM 4. In the figure,
The PEL counter value is a time-series display of the existence of a pulse generated every time the scanning line designates one pixel in the horizontal direction of the screen, and the control ROM outputs (1), (2), (3 ),(Four)
Generates a constant output signal in proportion to the vertical stripe width corresponding to the current TV size, high-definition TV size, storage system large screen, and storage system small screen, respectively (in the example,
It is shown in the ratio of 3, 6, 9, 2. ). The control ROM is
As described above, the switching is performed according to the screen size. On the other hand, the conversion ROM stores output patterns a, b, c, d, e, f (for example, color patterns of red, blue, etc.) corresponding to each address, and outputs the control patterns according to the control ROM output. The output patterns a, b, c, d, e, f are sequentially output. When one horizontal scan is completed, the same process is repeated, and as a result, a vertical stripe as shown in the lower part of the figure is obtained on the screen.

FIG. 4 is an explanatory diagram of the occurrence of horizontal stripes. In this case, it is assumed that the selector 6 is switched to the vertical direction control ROM 5. In the figure, the line counter value is a time-series display of the existence of a pulse generated each time the scanning of each horizontal scanning line on the screen is started.
OM output (1), (2), (3), (4) are the current TV size,
A constant output signal is generated in proportion to the horizontal stripe width corresponding to a high-definition TV size, a large screen of the storage system, and a small screen of the storage system. When the PEL counter 1 finishes counting corresponding to all pixels in the horizontal direction, the line counter 2 advances the count by 1. In response to this, the output of the control ROM holds a constant output for a predetermined number of scanning lines, as in the vertical stripe generating mechanism. Control R
As in the case of FIG. 3, the stripe width at which the output of the conversion ROM is generated is determined corresponding to the cases where the OM output is (1), (2), (3), and (4). Thus, a horizontal stripe is obtained on the screen as shown at the bottom of the figure.

FIG. 5 is an explanatory view of a mixture of vertical and horizontal stripes. In this case, it can be realized by switching the selector 6 at an appropriate timing in the middle of one frame. FIG. 6 is an explanatory diagram of a pseudo moving image. Since it is essentially independent of the screen size, the case of the control ROM output (1) in FIG. 3 will be described. When making a pseudo moving image, since the data position may be changed with respect to the previous frame, the address space of the conversion ROM is prepared twice as much as the case of the still image described above, and the increased portion of the still image is temporally divided. The value deviated from is output. As a result, as shown in the lower part of the figure, the conversion ROM output is the Nth frame and the N + th frame.
One frame will be shifted in time. That is, since the conversion ROM output changes alternately between the Nth frame and the N + 1th frame, a pseudo moving image is formed. Although the vertical stripes have been described above as an example, a pseudo moving image can be obtained in exactly the same manner in the case of horizontal stripes and in the case of both vertical and horizontal stripes. Also, in the above, the conversion R is alternated every other frame.
Although it has been described that the OM output is changed, in general, the conversion ROM output is alternately changed every M frames,
It is possible to realize a pseudo moving image that can be visually grasped.

[0014]

EFFECTS OF THE INVENTION A test pattern of vertical stripes, horizontal stripes, a mixture of vertical / horizontal stripes, and pseudo moving images can be formed with a small-scale circuit. Therefore, debugging and maintenance / inspection during development can be facilitated.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of occurrence of vertical stripes.

FIG. 4 is an explanatory diagram of occurrence of horizontal stripes.

FIG. 5 is an explanatory diagram of generation of vertical / horizontal stripe mixed patterns.

FIG. 6 is an explanatory diagram of generation of a pseudo moving image pattern.

FIG. 7 is a conventional configuration example.

[Explanation of symbols]

 1 PEL Counter 2 Line Counter 3 Frame Counter 4 Horizontal Direction Control ROM 5 Vertical Direction Control ROM 6 Selector 7 Pattern Generation ROM (Conversion ROM) 8, 9 Pattern Generation ROM

Claims (4)

[Claims] 1. An image test pattern generation circuit for reading image information from a pattern generation ROM by a counter output of an image encoding device, wherein a horizontal control ROM (4) outputs a counter output corresponding to a fixed number of pixels. On the other hand, one pattern generation ROM read signal is generated, and the test pattern signal of the vertical stripe is generated by sequentially reading the test pattern signal from the pattern generation ROM (7) by the pattern generation ROM read signal. Image test pattern generation circuit. 2. An image test pattern generation circuit for reading image information from a pattern generation ROM by a counter output of an image encoding device, wherein a counter output corresponding to a certain number of scanning lines in a vertical direction control ROM (5). One pattern generation ROM read signal is generated for each of the two patterns, and the test pattern signals are sequentially read from the pattern generation ROM (7) by the pattern generation ROM read signal to generate a horizontal stripe test pattern. Image test pattern generation circuit. 3. An image test pattern generation circuit for reading image information from a pattern generation ROM by a counter output of an image encoding device, wherein one pattern generation ROM read signal is provided for the counter output corresponding to a fixed number of pixels. Which has a horizontal direction control ROM (4) and a vertical direction control ROM (5) which generates one pattern generation ROM read signal for the counter output corresponding to a fixed number of scanning lines. By switching the output of the direction control ROM and the output of the vertical direction control ROM at an appropriate timing by using the selector (6), the test pattern signal is sequentially read from the pattern generation ROM (7), and An image test pattern generation circuit, which generates a test pattern in which horizontal stripes are mixed. 4. The test pattern to be stored in the pattern generating ROM (7) according to claim 1, claim 2 or claim 3, in addition to the first test pattern, there is a time difference from the test pattern. A second test pattern is additionally stored, and a pseudo moving image test pattern is generated by switching between the first test pattern and the second test pattern for every fixed number of frames. Generator circuit.