JP3143502B2 - Area discriminating apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an area discriminating apparatus and method for discriminating a designated area in an original image based on image contents in the original image.

[0002]

2. Description of the Related Art Conventionally, a method of discriminating an area of a predetermined color such as a marker without taking an image into a storage means such as a bit map memory is disclosed in Japanese Patent Laid-Open No. 64-80165.
As described in Japanese Patent Application Laid-Open Nos. 62, 9, 21 (“Image Processing Apparatus”), an area is determined using two lines of a predetermined color image signal and an area determination signal of a previous line.

[0003]

However, in the above-mentioned conventional example, as shown in FIG. 15, the area where the loop is formed in a double or triple manner is ignored except for the outermost area, and the loop in the scanning direction is ignored. As for the image whose end is concave, it is not possible to distinguish the inside and outside of the area as shown by the shaded area on the right.

[0004] Since the discrimination method is used in this manner, the shape of the discrimination area changes depending on, for example, the direction of the document image, and it becomes very difficult to use the image processing when it is desired to perform image processing inside and outside the area.

The present invention has been made in view of the above points, and provides an area discriminating apparatus and method capable of discriminating a designated area almost in real time without requiring a large memory capacity. With the goal.

According to the present invention, there is provided an area discriminating apparatus for discriminating a designated area on an original image based on the image content of the original image. Sample means for sampling at least two of data of a change point of a signal representing the data and data of a change point of an area signal indicating the specified area determined in the previous line; and a pattern for the data sampled by the sample means. Pattern matching means for performing matching, first storage means for storing processing results of the pattern matching means, and second storage means for storing data of the change points
And generating an area signal indicating the designated area by reading data from the first storage means based on the data stored in the second storage means. Discriminator. Further, the area determination method of the present invention is an area determination method for determining a designated area on the original image based on the image content of the original image, wherein a change in a signal representing a predetermined color in the original image is performed. A sample step of sampling at least two of point data and data of a change point of an area signal indicating the designated area determined in the previous line, and a pattern for performing pattern matching on the data sampled in the sample step A matching step, a first storage step of storing a processing result of the pattern matching step in a first storage means, and a second storage step of storing data of the change point in a second storage means, The designated area is indicated by reading data from the first storage means based on the data stored in the second storage means. And wherein the generating the frequency signal.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments.
FIG. 1 is a block diagram of the present embodiment.
Reference numeral 1 denotes a CCD line sensor for reading a document, and a red filter and a cyan filter are alternately applied to elements forming one pixel. The light level signal output from the line sensor is defined as an R signal 102 and a C signal 103.

These signals are respectively supplied to amplifiers 104, 1
The digital signal is amplified by an A / D converter 106 and converted into an analog signal by A / D converters 106 and 107. The shading circuits 108 and 109 correct the inherent variation of the line sensor 101 and the light amount unevenness of a light source for illuminating the original when reading the original. And the density of the original image can be accurately obtained.

Next, the color discrimination circuit 110 discriminates the predetermined color and the black level from the difference component between the red signal and the cyan signal for each pixel. This discrimination will be described with reference to FIG.

First, a description will be given assuming that the predetermined color (a marker or the like that draws a closed loop for determining an area described later) is red. If the difference component obtained by subtracting the cyan signal from the red signal is larger than a constant r, the pixel is determined to be red, and (D) shown in FIG.
In the case other than red, if the cyan signal is larger than the constant k, the signal becomes the black signal 112.

Next, an output signal 116 is obtained from the red signal 111 by using a region selection signal 114 obtained by a region determination circuit 113 and a black signal 112 by a signal selection circuit 115 for image processing such as masking and trimming.

Next, the automatic determination of a region based on a predetermined color performed by the region determination circuit 113 will be described in detail with reference to FIG. The red signal 111 (D signal 504 in FIG. 3, hereinafter referred to as a D signal) whose color has been determined by the color determination circuit 110 in FIG. 1 and a region determination signal for the previous line (corresponding to (A) in FIG. 501), an inner region signal of the previous line (corresponding to (B) in FIG. 3; hereinafter described as a B signal 502), and a region end signal of the previous line (corresponding to (C) in FIG. 3; hereinafter a C signal) 503) will be used to determine the area.

First, the latch data enable signal 510 is obtained by ORing the four signals of the change point signals 507, 508, and 509 of the A signal, the C signal, and the D signal with the change point extracting unit and the signal output by the sending circuit 517. Is obtained.

What the sending circuit 517 performs is to store the latch data which can be stored in the pattern matching unit and the discrimination signal generation circuit after the video enable is turned off.
Signals are sent for the number of delays in order to send the signals to Fos 530, 531, and 532.

A change point of the A signal, the B signal, the C signal, and the D signal is determined by the flip-flop 52 by the latch data transfer clock 511 obtained by ANDing the data enable signal 510 and the inverted signal of the video transfer clock 505.
0, 521, 522, and 523.

Each change point signal is subjected to pattern matching by a 5 × 4 matrix obtained by a flip-flop in the first half of the pattern matching unit.

Next, an algorithm for pattern matching will be described. In FIG. 4, attention lines m, n,
The o and p area determination will be described.

FIG. 5 shows the area discrimination on the m-th line. Am-1 (501 in FIG. 3) indicating the discrimination area one line before from the top
Bm-1 indicating a discrimination region not including the red portion one line before (corresponding to 502 in FIG. 3). Cm-1 indicating the red portion surrounded by the Bm-1 (corresponding to 502 in FIG. 3) one line before. 3 of 503
), Dm indicating the red part of the line of interest (504 in FIG. 3).
Is determined using the four lines (corresponding to.).

When any one of the data points of Am-1, Cm-1, and Dm is observed, the data (Am-1, Bm-1, Cm-1, Dm) immediately after the changed point is latched. I will do it. The search is performed while shifting the data for three pixels, and a part of the search is shown below. However, x is undefined.

Am-1 111 Bm-1 xxx Am 111 Cm-1000 → Bm 010 Dm 101 Cm 000 As described above, Am-1 is 111, Cm-1 is 000, Dm
Is 101, Dm is converted from 0 to 1 to Am, Bm is converted data to 1 and the other data to 0. The determined Am (corresponding to 513 in FIG. 3), Bm (corresponding to 514 in FIG. 3), Cm (51 in FIG. 3)
5) correspond to (A), (B) and (C) shown in FIG.

Further, the configuration may be such that four pixels and five pixels are viewed.

Next, the area discrimination on the n-th line in FIG. 4 will be described with reference to FIG. Basically, the operation of searching for (C) shown in FIG. 6 is repeated while filling the determined area.

As described above, the data immediately after the change points of An-1, Cn-1, and Dn are respectively latched. Then, the search is performed while shifting the data for three pixels in the same manner as described above, and a part thereof is shown below.

An-1 111 Bn-1 x11 An x1x Cn-1 xxx → Bn x0x Dn 010 Cn x1x is converted as shown above, and the convex portion of the red signal (D) inscribed in (B) shown in FIG. The detection of the start point (C), which is the determined signal, is shown.

Next, the area discrimination at the o-line in FIG. 4 will be described in the same manner as described above with reference to FIG. Basically, the operation of searching for (C) shown in FIG. 6 is repeated while filling the determined area. As described above, An-1, Cn-1,
Data immediately after the change point of Dn is latched. Then, the search is performed while shifting the data for three pixels in the same manner as described above, and a part thereof is shown below.

Ao-1 xxx Bo-1 xxx Aox1x Co-1 111 → Boxxx Dox1x Cox1x The signal is converted as shown above, and a signal (C) shown in FIG. 6 is detected.
However, it is assumed that Co-1 only needs to have one out of three pixels.

The determination for detecting the end of the signal (C) will now be described. The area discrimination on the p-line in FIG. 4 will be described with reference to FIG. As described above, the search is performed while shifting the data for three pixels, and the detection of the center portion is shown below.

Ap-1 111 Bp-1 xxx Ap 101 Cp-1 111 → Bp xxx Dp 101 Cp x0x As shown above, since Cp-1 is not 000,
The conversion of Dp 101 → 111 is not performed. By this operation, as shown in FIG.
The signal or the signal (A) is excluded without being determined. This makes it possible to perform the area determination shown in FIG.

Returning to FIG. 3 again, the signal 512 obtained by the pattern matching produces the (A) signal 513, the (B) signal 514, and the (C) signal 515 of the line of interest, and each of them is FiFo (530, 531, 532).
Write to

At this time, in order to prevent unnecessary data remaining in the pattern matching unit and the discrimination signal generation circuit from being written to the FIFO from the latch enable signal, the unnecessary unit mask circuit 518 outputs signals for the number of unnecessary data such as video enable. Then, only the necessary latch data is written by the write enable signal 519.

At the same time, the latch enable signal is
516 which was written to 33 and read one line later
Is used as a read enable signal for restoring the latch data written at the timing of the change point written in the FIFOs 530, 531, and 532.

The area signal 501 read from the FiFo 530 is shaped by a flip-flop and output as an area determination signal.

In the present embodiment, the area indicated by the color is determined for the signal whose color has been determined. However, the present invention is not limited to this, and all areas can be determined by a binary image using a raster method.

(Other Embodiment) Another embodiment will be described in detail.

The description of the previous embodiment shown in the block diagram of FIG. 1 is omitted.

The automatic determination of an area based on a predetermined color performed by the area determination circuit 113 will be described in detail with reference to FIG.

The red signal 111 (D signal 1201 in FIG. 11, hereinafter referred to as a D signal) whose color is determined by the color determination circuit 110 in FIG.
Region determination is performed based on the signal. A signal 1 indicating a circuit for latching the transition points of two signals to the transition point extraction unit
202, a latch data enable signal 1210 is obtained by ORing the three signals of the change point signal of the D signal 1201 and the signal output from the sending circuit 1203.

In the sending circuit 1203, after the video enable is turned off, the latch data which can be sent to the pattern matching unit and the discrimination signal generation circuit is transmitted to the FiFo 120.
7 and 1208, signals are output for the number of delays.

A latch data transfer clock 121 obtained by ANDing this signal 1210 and an inverted signal of the video transfer clock
At 1, the transition points of the A signal and the D signal are latched in the flip-flops.

Each change point signal is subjected to pattern matching using a 3 × 2 matrix obtained by a flip-flop in the first half of the pattern matching section.

Next, the algorithm of pattern matching will be described. In FIG. 4, attention lines m, n, p
Will be described. FIG. 12 shows the area determination for the m-th line.

Am- indicating the discrimination area one line before from the top
1. A region is determined using two lines of Dm indicating a red portion of the line of interest. If there is at least one change point in the data of Am-1 and Dm, the data (Am-
1, Dm). Then, the search is performed while shifting the data for three pixels, and a part thereof is shown below.
However, x is undefined.

Am-1 111 Dm 101 → Am 111 As described above, when Am-1 is 111 and Dm is 101, the value obtained by converting 0 of Dm to 1 is Am, that is, the determined area.

Similarly, in the area discrimination on the n-th line in FIG. 4, the search is performed while shifting the data of three pixels in the same manner while converting the Dn signal into the area signal as shown in FIG. Some of them are shown below.

An-1 11111 Dn 10101 → An 11111 The conversion is performed as described above, and next, the area determination on the p-line in FIG. 4 will be described with reference to FIG. 14 in the same manner as described above. As described above, the search is performed while shifting the data for three pixels, and the detection of the center portion is shown below.

Ap-1 1111111 Dp 1010101 → Ap 1111111 As shown above, 2 × 3 pattern matching (1 in FIG. 11)
In 204), when Ap-1 is 111 and Dp is 101, the center 0 of Dp is always replaced with 1, and the signal (1205 in FIG. 11) is determined as the area signal Ap111. By repeating this operation, the determination in FIG. 10 can be realized with a simple circuit and at low cost.

The area signal 1205 of FIG.
Write to 07. At this time, in order to prevent unnecessary data remaining in the pattern matching unit and the discrimination signal generating circuit from being written into the FIFO from the latch enable signal, the unnecessary unit mask circuit 1206 outputs signals corresponding to the number of unnecessary data of the video enable head. Only the necessary latch data is written by the write enable signal.

At the same time, the latch enable signal is
The read enable signal 1210 is used as a read enable signal for restoring the latch data of the change point written in the FIFO 1207 by the read enable signal 1210 read by delaying one line.

The read area signal 1202 is shaped by a flip-flop and output as an area determination signal 1209.

As described above, even if the orientation of the document is changed, the shape of the determined area does not change significantly, and when the area is further designated by the same color inside the area, the area inside Judge as outside. As a result, a function of designating a plurality of areas can be obtained, and furthermore, the time required for reading an image and performing this processing in real time can be greatly reduced.

Further, the present invention can be realized at low cost without having to have a bitmap memory or the like. Further, since the processing delay required to determine the area is only one scan, the amount of multi-valued image delay memory that must be delayed accompanying the processing is small, leading to cost reduction.

[0051]

As described above, according to the present invention, it is possible to determine a designated area almost in real time without requiring a large memory capacity.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image reading apparatus.

FIG. 2 is a flowchart illustrating a procedure of color determination.

FIG. 3 is a block diagram of an area determination circuit.

FIG. 4 is a diagram illustrating an area determination operation.

FIG. 5 is a timing chart illustrating an area determination operation.

FIG. 6 is a diagram illustrating an area determination operation.

FIG. 7 is a timing chart illustrating an area determination operation.

FIG. 8 is a timing chart illustrating an area determination operation.

FIG. 9 is a timing chart illustrating an area determination operation.

FIG. 10 is a diagram showing an area determination operation.

FIG. 11 is a block diagram of an area determination circuit.

FIG. 12 is a timing chart illustrating an area determination operation.

FIG. 13 is a timing chart illustrating an area determination operation.

FIG. 14 is a timing chart illustrating an area determination operation.

FIG. 15 is a diagram illustrating an area determination operation.

[Explanation of symbols]

 101 CCD line sensor 104 amplifier 105 amplifier 110 color discriminating circuit 113 area discriminating circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-127285 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06T ^7/ 00-7/60 350 G06T 1 / 00

Claims (3)

(57) [Claims] An area discriminating apparatus for discriminating a designated area on an original image based on image content of the original image, comprising : data of a change point of a signal representing a predetermined color in the original image ;
An area signal indicating the specified area determined in the previous line
Sampling means for sampling at least two of the data at the change point of the signal; pattern matching means for performing pattern matching on the data sampled by the sampling means; and a first means for storing a processing result of the pattern matching means.
And a second storage means for storing the data of the change point. By reading data from the first storage means based on the data stored in the second storage means, An area discriminating device for generating an area signal indicating a designated area. 2. An area discriminating apparatus according to claim 1, further comprising image processing means for performing image processing on said original image based on an area signal generated by said area signal generating means. 3. An area discriminating method for discriminating a designated area on an original image based on image content of the original image, comprising : data of a change point of a signal representing a predetermined color in the original image ;
An area signal indicating the specified area determined in the previous line
A sample step of sampling at least two of the data of the signal change point; a pattern matching step of performing pattern matching on the data sampled by the sample step; and a first storage unit for storing a processing result of the pattern matching step. A first storage step of storing the data of the change point in a second storage unit.
Storing an area signal indicating the designated area by reading data from the first storage means based on data stored in the second storage means. Judgment method.