JPH067389B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention According to the present invention, an input pattern is obtained by binarizing an image input of characters, figures, etc. into black and white, and a matching process such as a dictionary is executed for this input pattern to obtain an unknown pattern. The present invention relates to a technique for recognizing characters and the like, and more particularly, the present invention relates to an image processing apparatus for tracking the contour line of an input pattern at high speed prior to the matching process.

<Background of the Invention> As shown in FIG. 10, a conventional device of this type has a camera 21 which is a CCD (Charged-Coupled Device) for characters and figures.
The image is converted into a black and white image by the binarization circuit 22.
After binarizing the input pattern and storing the input pattern in the image memory 23, the contour tracking circuit 24 is operated for the input pattern in the image memory 23 to execute the contour line tracking process. In this contour tracking processing, the mask 25 shown in FIG. 11 is set on the image memory 23, and the mask 25 is scanned in a predetermined direction (indicated by an arrow in the drawing), and the pixel data S and four directions around the pixel data S for each pixel. After checking the pixel data S _{0 to} S ₃ in the vicinity and obtaining the tracking start point based on the data structure, the contour black pixels of the input pattern are sequentially tracked in a predetermined direction.

In this case, when the tracking processing for the first contour line is completed, the above scanning is restarted, the next tracking start point is detected, and the same contour line tracking processing is executed. When the tracking processing is completed for all the contour lines and the tracking start point cannot be found, all the processing of contour line tracking is completed (see the flowchart of FIG. 12).

Therefore, according to the above-mentioned conventional method, when a large number of contour lines are included in the image memory, five pixels are accessed in the mask for each scanning position in order to detect the tracking start point of each contour line. This needs to be done across the image memory. For this reason, the processing time for detecting the tracking start point in the contour tracking processing becomes remarkably long, which is a factor that reduces the processing efficiency of the contour tracking, and thus the pattern recognition processing efficiency.

<Objects of the Invention> The present invention provides an image processing apparatus that speeds up the detection of a tracking start point when tracing the contour line of an input pattern, thereby shortening the contour tracing processing time and further improving the pattern recognition processing efficiency. The purpose is to measure.

<Structure and Effect of the Invention> In order to achieve the above object, according to the present invention, binary image data forming an input pattern and tracking processing data set during contour tracking processing are input to an image memory for storing an input pattern. The contour flag set in the contour constituent pixels of the pattern and the pair flag set according to the tracking direction to the next contour constituent pixel are configured to be stored corresponding to each pixel, and the contour tracking start point detection processing is performed. In this case, the image memory is scanned in a predetermined direction and each pixel is sequentially accessed to take in binary image data and tracking processing data of each pixel, and the access target pixel is input for which contour tracking processing has been completed based on the data contents. Whether the pixel is located inside or outside the pattern is recognized, and based on the recognition result, it is determined whether or not the pixel is used as the starting point of the contour tracking process. I decided to set it.

According to the present invention, when the contour tracking start point is detected by scanning the image memory, all the pixels of the image memory need only be accessed once, and the tracking start point in the contour tracking process can be detected easily and quickly. In addition, the processing time for contour line tracking can be greatly shortened, and the efficiency of pattern recognition processing can be improved.

<Description of Embodiments> FIG. 1 shows a configuration example of a pixel processing device according to the present invention.

The apparatus of the illustrated example stores an image memory 1 that stores an input pattern formed by binarizing an image input in a plurality of vertical and horizontal pixel ranges, and scans the image memory 1 in a predetermined direction to sequentially access each pixel. A scanning circuit 2, a state recognition unit 3 for sequentially capturing data of each pixel of the image memory 1 and recognizing a pattern state of a currently accessed pixel, and a contour tracking of the pixel based on a recognition result of the state recognition unit 3. Control ROM (Read Only) that determines whether to detect as a start point
Memory) 4 and. In each pixel of the image memory 1, 8-bit data b _{0 to} b ₇ shown in FIG. 2 is stored. In the case of the present embodiment, the 0th bit b ₀ is binary. Image data (black pixel is “1”, white pixel is “0”), 6th bit b ₆ is pair flag (“1” or “0”), 7th bit b ₇
Is a contour flag (contour points are "1", other points are "0")
But each is set. The pair flag and the contour flag are set only for the pixels for which the contour line tracking processing has been executed. In the case of the input pattern 5 shown in FIG. 3, the contour flag “1” is assigned to the pixel marked with a circle in the figure. Further, the pair flag "1" is set to each of the shaded pixels.

4 to 6 show a pair flag setting method. Now, for the input pattern 6 shown in FIG. 4, when the contour line is traced as indicated by the arrow in the figure, when the contour line is traced from one pixel T _{0 to the} next pixel T ₁ , the tracing direction is changed each time. It is specified by the 8-direction code shown in FIG. 5, and the procedure shown in FIG. 6 is executed to set a pair flag in the corresponding pixel. In FIG. 6, step 1 (indicated as "ST1" in the figure) and step 2 are for determining the direction code dir. When the direction code dir is 1, 2, or 3, step 1 Becomes "YES", and the pair flag of the pixel T ₀ related to the tracking source is inverted (step 3). When the direction code dir is 5, 6, or 7, step 2 becomes "YES", and the pair flag of the pixel T ₁ of the tracking destination is inverted (step 4). Further, when the direction code dir is either 0 or 4, both step 1 and step 2 become “NO”,
The pair flag of both pixels T ₀ and T ₁ remains unchanged. The pair flag in each pixel is "0" in the initial state.

Thus, the image memory 1 stores binary image data for each pixel, data IMEM including a pair flag and a contour flag. By scanning the image memory 1 with a scanning circuit and sequentially accessing each pixel, The data IMEM of each pixel is sequentially taken into the state recognition unit 3. In this case, in the scanning circuit, the initial setting address adr is first latched in the latch circuit 7 and 1 is added in the address adding unit 8 to obtain the address Nadr for accessing the image memory 1, and the same adding process is repeated thereafter. Then, this address Nadr will be updated.

The state recognition unit 3 recognizes the state of the current access target pixel in the pattern based on the data IMEM. For example, as shown in FIG. 7, a pair flag is input and a code A is input from the Q terminal. It is composed of a flip-flop 9 which outputs an output indicated by and an OR circuit 10 which inputs the A output and the contour flag and outputs an output indicated by a symbol B. Assuming that the input pattern 5 shown in FIG. 3 is scanned in the direction of the arrow in FIG. 3, a pair flag, a contour flag, an A output,
The levels of the B output are as shown in the figure, and it can be seen that the B output corresponds to the state of the pattern. Therefore, if the B output is a logical "1", it can be determined that the access target pixel is located inside the input pattern, and if it is a logical "0", the access target pixel is located outside the input pattern.

Based on the recognition result of the state recognition section 3, the next control ROM 4 judges whether or not the pixel to be accessed is detected as the contour tracking start point. If the tracking start point is not set, the LC output is the latch circuit 7 Send to address Nadr
When the tracking start point is set, the END output is output and the tracking start point address Sadr is obtained.

FIG. 8 shows a determination table of the tracking start point in the control ROM 4, in which P1 to P5 correspond to P1 to P5 of each point on the image memory 1 shown in FIG. In the image memory 1 shown in FIG. 9, the first contour-tracked first
Input pattern 11 (in the figure, a circle indicates a pixel of contour flag “1”) and an unprocessed second input pattern 12 are stored, and points P1 to P3 are the first input pattern 11 , The point P4 is located inside the second input pattern 12, and the point P5 is located outside both input patterns 11 and 12. Thus, the control ROM 4 makes the above determination based on the contents of the B output, the contour flag and the binary image data. In the example shown in FIG. 8, the B output logic is "0",
A point P4 where the contour flag is "0" and the binary image data is logical "1" is detected as the contour tracking start point.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration example of a binary image processing device according to the present invention, FIG. 2 is a diagram showing a format of data stored in each pixel of an image memory, and FIG. 3 is an input pattern and each FIG. 4 is a diagram showing a correspondence relationship between a flag and an output, FIG. 4 is a diagram for explaining a contour line tracking process of an input pattern, FIG. 5 is a diagram for explaining an 8-direction code, and FIG. 6 is a pair flag setting process. Flow chart showing operation, No. 7
FIG. 8 is a circuit diagram showing a specific circuit of the state recognition unit, FIG. 8 is a diagram showing a tracking start point detection table, FIG. 9 is a diagram showing each point on the image memory corresponding to FIG. 8, and FIG. FIG. 11 is a block diagram showing an apparatus configuration of a conventional example, FIG. 11 is a diagram for explaining a contour tracking start point detecting process of the conventional example, and FIG. 12 is a flowchart showing the contour tracking process. 1 ... Image memory, 2 ... Scan circuit 3 ... Status recognition unit 4 ... Control ROM

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Miyamune, Tateishi Life Science Institute, No. 3 Nakamimon-cho, Hanazono, Ukyo-ku, Kyoto City, Kyoto Prefecture (56) References JP-A-60-263276 (JP, A)

Claims (1)

[Claims] 1. An image processing apparatus comprising contour tracing means for tracing contour lines of a black and white binarized input pattern, wherein binary image data constituting the input pattern and contour tracing processing by the contour tracing means. It is possible to store, for each pixel, the contour flag set in the contour constituent pixels of the input pattern and the pair flag set according to the tracing direction to the next contour constituent pixel as the tracking processing data which is set at any time. An image memory, a scanning unit that scans the image memory in a predetermined direction to sequentially access each pixel, a binary image data of each pixel accessed by the scanning unit and the tracking processing data are fetched, and an access target pixel is Recognizing means for recognizing the position inside or outside the input pattern for which the contour tracking processing has been performed, and the access means based on the recognition result by the recognizing means An image processing apparatus comprising: a contour tracking start point detecting means for deciding whether or not to detect a target pixel as a start point of contour tracking processing.