JPH0466153B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a two-dimensional system that prevents malfunctions by floating the binarization slice level.
The present invention relates to a digitized image processing device.

[Conventional technology]

FIG. 8 is a block diagram showing the configuration of a conventional binarized image processing device. In this FIG. 8, reference numeral 1 indicates an object, which is imaged by a television camera 2 (hereinafter referred to as camera), and the video signal obtained by this camera 2 is sent to a monitor television 3, which displays the original image of the object 1. is starting to appear in the image.

Further, the video signal is sent to a comparator 5 via a video amplifier 4, where the video signal is compared with a reference voltage and converted into a binary value.

Binarized video data A is AND gate 6
The logical AND with the contents B of the mask image memory 7 is calculated by . The output C of the AND gate 6 is stored in the binarized image memory 8. Data transmission between the mask image memory 7, the binarized image memory 8, and the AND gate 6 is performed via a bus line 13 of the computer.

On the other hand, the synchronization signal generator 14 generates a signal for synchronizing the camera 2, the mask image memory 7, and the binarized image memory 8, and sends the signal to these.

Further, 9 is a processor for processing a binarized image, and a program memory 10 for this processor 9, an output port 11 for outputting judgment results, and an input port 12 for receiving commands are all connected to a bus line 13. ing.

FIG. 9 shows video data A output from the comparator 5, which shows that the object 1 has a binarization level of "1" and a background value of "0".

Further, FIG. 10 shows the contents (image) B of the mask image memory 7 that are input to the AND gate 6. Here, the term "mask" refers to a function of predetermining a region of interest so that only a partial region of an image is targeted. The logical product of FIGS. 9 and 10 becomes the output C of the AND gate 6, as shown in FIGS. It is stored. The processor 9 determines the area, centroid, etc. from the binarized image stored in the binarized image memory 8, and makes judgments depending on the purpose.

[Problem that the invention seeks to solve]

However, in such a conventional binarized image processing device, the slice level (threshold) when binarizing a grayscale image is fixed over the entire screen in the comparator 5. .

In practice, there is shading (even if a planar object with the same illuminance is photographed, the center of the screen is bright and the periphery of the screen is dark) and uneven illumination within the screen. When binarized at a fixed slice level, the shape of the binarized image changes greatly depending on the position of the object 1 in the screen.

FIGS. 12a and 12b show examples of one-dimensional video output. When the object 1 is located at the periphery of the screen as shown in FIGS. 12a and 12b, an area where the background video level is high may be sliced.

[Means for solving problems]

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional art. /D converter and the digital signal output from this A/D converter, the digital signal of the grayscale image of only the background excluding the object is stored, an offset value is added to the content, and the digital signal of this content is The mask function sets the highest data for the area excluded from the image memory, and compares the magnitude of the digital value between the digital signal output from the A/D converter and the content stored in the image memory. a digital comparator that outputs a binarized signal depending on whether or not a condition is satisfied that the output of the A/D converter is greater than the content of the image memory; and a binarized image memory that stores the output of the digital comparator. It was established.

[Effect]

Since the present invention is configured as described above, a shading image of only the background excluding the target object is obtained from a digital signal obtained by A/D converting the video signal obtained by imaging the target object and the background with a television camera. After storing the digital signal in the image memory, an offset value is added to it, and the highest data is set for the area excluded from the target area using the mask function among the stored contents, and the contents of this image memory are combined with the A/D signal.
A digital comparator compares the magnitude of the digital value of the output of the converter, and compares whether the output of the A/D converter is larger than the content of the image memory. Since the binarized signal is stored in the binarized image memory, it is possible to sufficiently cope with conditions with uneven illumination, and the slice level can be set finely.

〔Example〕

Embodiments of the binarized image processing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment. This first
In the figure, parts that are the same as those in FIG. 8 are given the same reference numerals to avoid duplication, and parts that are different from those in FIG. 8 will be described with emphasis. As is clear from comparing FIG. 1 with FIG. 8, in FIG.
The signal is sent to a digital comparator 22 through a digital converter 21.

Digital comparator 22 is A/D converter 2
1 and the output of the data latch 23 are compared in magnitude. The output of the A/D converter 21 and the output of the data latch 23 have multiple levels and are usually 8-bit wide data. The output of this digital comparator 22, that is,
The results of the comparison are stored in the binarized image memory 8 through the bus line 13.

Further, the output of the image memory 24 is held in the data latch 23 through the bus line 13. This image memory 24 is a characteristic part of the present invention, and is an image memory having a function of both a floating binarization slice and a mask.

The synchronization signal generator 14 generates a synchronization signal of the camera 2,
The timing of the A/D converter 21, the data of the binarized image memory 8, and the image memory 24 are sequentially transferred to the bus line 13.
This is to create the timing for input and output.

Thus, the differences from the conventional example are the A/D converter 21, the digital comparator 22, the data latch 23, and the image memory 24. Of these, the bit width of the image memory 24 is matched to that of the A/D converter 21. Therefore, when used in an 8-bit A/D converter 21, the bit width of the image memory 24 is also adjusted to match the 8-bit A/D converter 21.

Note that the capacities of the binarized image memory 8, processor 9, and image memory 24 depend on the screen size.
For example, when dividing a screen into 256 pixels vertically and 256 horizontally, each pixel occupies 256 x 256 = 64K bytes of address space.

Next, the operation of the binarized image processing apparatus of the present invention configured as described above will be explained with reference to the flowchart of FIG. 2 and FIGS. 3 to 7. First, as a preparatory work, floating binarization of the image memory 24 and setting of a mask image are performed. At step S1 in FIG. 2, the object 1 is first removed from the visual field, and a grayscale image of only the background is taken into the image memory 24.

This inputs the output of the A/D converter 21 directly to the image memory 24. FIG. 3 shows an example of video output versus position. In addition, in FIGS. 3 to 7, two-dimensional image data is treated as one-dimensional for simplicity.
In FIGS. 3 to 7, the vertical axis represents the video output indicating shading, and the horizontal axis represents the position within the screen. The video output on the vertical axis has a level of 0 to 255, which is ^28-1 =255, assuming that the A/D converter 21 is 8 bits. FIG. 3 shows the level of only the background, and shows that there is uneven illuminance in each space.

Next, in step S2 of FIG. 2, the processor 9 adds an offset to the contents of the image memory 24. This offset value is determined from the S/N of the video signal and the video level of the object 1. OF in Figure 4 shows this.

Next, in step S3 of FIG. 2, the screen is masked and the contents of the image memory 24 are replaced with the highest value for the area excluded from the calculation. Image memory 2
Since 4 is 8 bits wide, the maximum value is 2 ⁸ - 1 = 255
It is. FIG. 5 shows an example.

The preparation work is completed by the above operations, and the object 1 is placed on the screen as shown in step S4 in FIG.
Measurement work begins. In step S5 of FIG. 2, the video signal of the image of the object 1 taken by the camera 2 is amplified by the video amplifier 4, and then the A/D converter 21
A/D conversion is performed. The solid line in FIG. 6 is this A/D conversion output. Also, the dotted line in Figure 6 indicates step S.
This is the image data set in the image memory 24 by the operations up to 3.

After the video signal is digitally converted by the A/D converter 21 as described above, the digital value of the video signal and the digital value of the reference image set in the image memory via the bus line 13 are held in the digital comparator 22. The contents of the data latch 23 are compared in size.

The digital comparator 22 outputs "1" when the condition of A/D conversion output>reference image is satisfied, and "0" when the condition is not satisfied (≦). This output enters the binarized image memory 8 via the bus line 13. FIG. 7 shows the output of this digital comparator 22. That is, FIG. 7 is a comparison between the solid line and the dotted line in FIG. 6.

In step S5 of FIG. 2, the image memory 24 contains a value of 255 in the mask section, and the A/D
Regardless of the value of the conversion output, the comparator output of the digital comparator 22 is "0".

Furthermore, the non-masked portion contains a slice level image corresponding to the background video level, and floating binarization can be performed.

In the manner described above, a binarized image in which the non-masked portion of the object 1 is extracted can be set in the binarized image memory 8.

Incidentally, steps S6 and S7 in FIG. 2 perform the same processing as in the prior art.

〔Effect of the invention〕

As described above, according to the binarized image processing device of the present invention, the background excluding the object is converted into a digital signal obtained by A/D converting the video signal obtained by imaging the object and the background with a camera. After storing the digital signal of the image with only the light and shade in the image memory, an offset value is added, and the data with the highest value is set for the area excluded from the target area using the mask function among the stored contents, and the contents of this image memory are A digital comparator compares the magnitude of the digital value of the output of the A/D converter and the digital value of the output of the A/D converter, and converts a binary signal depending on whether the condition that the output of the A/D converter is larger than the content of the image memory is satisfied. Since it is stored in the converted image memory, it has both a floating slice level function and a mask function, and can be used even under conditions with uneven illumination.

Further, the vertical and horizontal pixel sizes of the image memory can be matched with those of the binarized image memory 8, and the slice level can be set finely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the binarized image processing apparatus of the present invention, FIG. 2 is a flowchart showing the operation flow of the binarized image processing apparatus of FIG. 1, and FIGS. The figures show the relationship between the video output and the position taken into the image memory in the binarized image processing device shown in Fig. 1, and Fig. 7 shows the relationship between the video output and the position stored in the binarized image memory in the binarized image processing device shown in Fig. 8 is a block diagram of a conventional binarized image processing device, FIG. 9 is a diagram showing the output of the comparator in the binarized image processing device of FIG. 8, and FIG. 10 is a block diagram of a conventional binarized image processing device. 8 is a diagram showing the output of the image memory in the binarized image processing device, FIG. 11a and FIG. 11b are diagrams showing the output of the AND gate in the binary image processing device of FIG.
2a and 12b are diagrams showing one-dimensional video output applied to the binarized image processing apparatus of FIG. 8, respectively. 1... Object, 2... Television camera, 3... Monitor TV, 8... Binarized image memory, 9... Processor,
10...Memory, 11...Output port, 12...Input port, 13...Bus line, 14...Synchronization signal generator, 2
1... A/D converter, 22... Digital comparator, 23... Data latch.

Claims (1)

[Claims] 1 A television camera that images the object and background to obtain a video signal, and an A/C that converts the video signal output from the television camera into a digital signal.
Among the digital signals output from the D converter and this A/D converter, the digital signal of the grayscale image of only the background excluding the above-mentioned object is stored, an offset value is added to the content, and an offset value is added to the content. An image memory that sets the highest data for the area excluded by the mask function, and a digital signal output from the A/D converter and the digital value of the content stored in the image memory. A digital comparator that outputs a binarized signal depending on whether or not the condition that the output of the A/D converter is greater than the content of the image memory is satisfied, and a binarized image memory that stores the output of this digital comparator. and means for adding an offset value to the image memory, setting the highest data, and performing binarization processing on the binarized image memory.