JPH06315080A - Masking method and device for microfilm reader - Google Patents

Abstract

PURPOSE:To make the range of a picture clear and easy to see by searching the frame line of an output picture by using a black frame, and adding the frame line to the picture. CONSTITUTION:One picture 12C of two pictures 12C and 12D is used as a selected picture, and the area of the picture 12D is made black. The picture 12C and one part of the picture 12D are included in a fixed area 16A of a microfilm 10A. A black frame 22A in the area 16A is detected by a black frame detecting means, and stored. At the time of selecting the selected picture, the picture at preliminarily decided position in the area 16A can be automatically selected. For example, the picture at the left hand edge, right hand edge, left-and-up corner, and left-and-down corner is used as the selected picture. The selection of the selected picture can be operated by inputting coordinates on a screen from a keyboard. Thus, the black frame is detected, and masking- processed, and the frame line of the picture is searched by using the black frame, and the frame line is added to the output picture, so that the output picture can be outputted to a printer to which the frame line of the picture is added, and the range of the picture can be made clear and easy to see.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a masking method for a microfilm reader, which detects a black frame generated around an image on a negative microfilm, erases it, and outputs it.
Apparatus for direct use in carrying out the method.

[0002]

2. Description of the Related Art On a negative microfilm, a transparent non-image portion is formed so as to surround the outside of an image on a document. When printing out an image of an original from this microfilm, it is necessary to output a range larger than the original so that the entire range of the original does not deviate from the output range.

FIG. 7 shows the relationship between microfilm and print output. On the microfilm 10, images 12 and 14 of an original having a certain size are recorded as negative images. Since the range 16 to be printed out is fixed, if this range 16 is printed out, the print images 12A of the images 12 and 14 on the print papers 18 and 20,
Black frames 22 and 24 are generated outside 14A.

A method of automatically discriminating and masking the black frames 22 and 24 has been proposed. One of the methods is a black frame if the image signal continuously outputs a fixed number N (for example, 224) of black pixels when the image on the scanning line 26 at regular intervals (for example, 1 mm) is read by the line sensor. It is determined to be 22, 24. The fixed number N = 224 is a length corresponding to 14 mm on the original, for example.

In this method, as shown in FIG. 7A, from the coordinate X at which the pixel distribution on the scanning line 26 changes from a white pixel to a black pixel, the coordinate x at which N black pixels are continuous is calculated. The coordinate X = x−N that is detected and traces back N pixels from the coordinate x is determined as a black frame. And a fixed interval (eg 1mm
The coordinates X _n , X _{n + 1} , X _{n + 2} , ... Of the black frame in order with respect to the _nth , _{n + 1} , _{n + 2} , ...
In the same manner, and a black frame range, that is, a masking range connecting the respective coordinates X _n , X _{n + 1} , ... Is calculated.

[0006]

However, if the black frame detected in this way is erased from the range to be printed out, the frame line of the image, that is, the frame line showing the outline of the document disappears, and the size of the image becomes unknown, There is a problem that it becomes difficult to see.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a masking method for a microfilm reader capable of clarifying a frame line of an image when a black frame is detected and erased. This is the first purpose. A second object is to provide an apparatus directly used for carrying out this method.

[0008]

According to the present invention, a first object of the present invention is to detect a black frame from an array of pixels indicated by an image signal obtained by reading a certain area of a microfilm and binarizing it, and erase the black frame for output. In the method, the frame line of the output image is obtained by using the detected black frame, and the frame line and the image with the black frame erased are output in an overlapping manner.

A second object is to use an image reading means for reading out a certain area of the microfilm, a binarizing means for binarizing the output of the image reading means, and a pixel indicated by the binarized image signal. A black frame detecting means for detecting a black frame from the array,
In a masking device for a microfilm reader, which comprises masking means for erasing the detected black frame, frame line calculating means for obtaining a frame line of an output image from the black frame detected by the black frame detecting means, and output for erasing the black frame by the masking means The present invention is achieved by a masking device for a microfilm reader, characterized in that it comprises a frame line adding means for adding the frame line to an image.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of an embodiment of the present invention,
Is an operation flow chart showing the operation, FIG. 3 is a detailed operation flow chart of the black frame correction, FIG. 4 is a view showing a print output example according to the present invention, FIG. 5 is a view showing another output example, and FIG. 6 is a histogram. FIG.

In FIG. 1, reference numeral 30 is a microfilm, which is wound from one of the two reels 32 and 34 to the other and runs. The light from the light source 36 is guided to the film 30 from below, and the transmitted light from the film 30 is projected onto the projection lens 38, the image rotation prism 40, and the reflection mirrors 42 and 44.
It is led to the screen 48 from the backside via 46.

A vertically movable plate 5 is provided on the back surface of the screen 48.
0 is provided so as to be movable in the horizontal direction, and a CCD line sensor 52 is attached to the movable plate 50. Therefore, by moving the movable plate 50 in the horizontal direction while reading the image incident on the line sensor 52, the screen 4
8 images can be read.

During the first image reading, the output signal of the line sensor 52 is passed through the changeover switch 54 shown in FIG. 1 to the first binarizing means 56 and the threshold detecting means 5.
8 is input. When the image is read for the second time, it is input to the second binarizing means 60.

As described above, since the scanning lines 26 (FIG. 7) for detecting the black frame are read at regular intervals (for example, 1 mm intervals), other scanning lines 26 corresponding to the image reading density are provided between the scanning lines 26. There will be scan lines left. For example, when reading a 1 mm width with 16 scanning lines 26, there are 15 scanning lines between the black frame detection scanning lines 26. Black frame detection scanning line 26
Scan lines other than the above, or black frame detection scan lines 26
All scan lines including the threshold value D as described below.
Used to calculate _TH .

In the present invention, the black frame detecting scanning lines 26 at regular intervals are input to the first binarizing means 56, and the other scanning lines are input to the threshold detecting means 58.

The black frame detecting means 58 has a histogram creating means 62 and a threshold value calculating means 64. The histogram creating means 62 creates the density histogram shown in FIG. 6 using the image signal of the line sensor 52 that has read the scanning lines other than the black frame detection scanning line 26. This histogram shows the distribution of the number of pixels with respect to the density D of each pixel.

Here, the histogram creating means 62 uses the n-th black frame detection scanning line 26 (n) and the preceding (n)
A histogram is obtained by 15 scanning lines between the -1) th black frame detection scanning line 26 (n-1). The threshold value calculation means 62 uses this histogram to calculate the threshold value D _TH (n) used for the n-th black frame detection scanning line 26 (n).

For example, in the histogram shown in FIG.
The mountain P ₁ on the white side is formed by the transparent portion of the film 10 outside the images 12 and 14 in FIG. 7. The mountain P ₂ on the black side is formed by the background in the images 12 and 14. Therefore, the required image will be distributed between the two peaks P ₁ and P ₂ . The threshold value calculation means 64 finds the density D _TH of a certain ratio (for example, 70%) with respect to the density D ₂ of the mountain P ₂ as a threshold value for binarization, and stores the result.

In the threshold value detecting means 58, the (n-1) th and nth black frame detecting scanning lines 26 (n-1), 2
The threshold value D _TH (n) is obtained as described above with 15 scanning lines between 6 (n). This threshold D
_TH (n) is used for black frame detection of the nth black frame detection scanning line 26 (n) to be read thereafter. At this time (n
A histogram may be created including the -1) th black frame detection scanning line 26 (n-1).

The first binarizing means 56 uses the threshold value D _TH (n) thus obtained by the threshold value detecting means 58 to determine the image signal of the nth scanning line 26 (n). Binarize. This binarized signal is input to the black frame detecting means 66, where the black frame is detected and stored.

The black frame detecting means 66 can detect the black frame 2 by various methods.
2, 24 (see FIG. 7) are detected. For example, as described above, the scanning line 26 may be included in the range of the image 12 and N black pixels may be continuously arranged to detect the black frame (see (A) of FIG. 7). Further, as shown in FIG. 7B, a of a continuous N (for example, 160) pixels is a.
% (For example, 30%) is a black pixel, the presence of a black frame is detected, and Nb is calculated from the coordinate x at which the number of black pixels becomes a%.
The coordinate X = x-Nb that goes back by pixels may be determined as a black frame.

In this case, the Nb pixel has a range of (1
-B): It indicates the number of dots up to the coordinate divided into the ratio of b, and it is desirable to set b≈a. Note that the above description has been given of the case where the scanning enters from the outside of the images 12 and 14 into the images 12 and 14, but when the scanning goes from the inside of the images 12 and 14 to the outside, the black pixel of the above description is displayed. The white pixels may be reversed. When the black frame is detected by various methods in this manner, the black frame range is determined by connecting the points of the black frame obtained for each scanning line 26, and the black frame range is stored.

On the other hand, in a range where a certain area of the microfilm 30 is projected and displayed on the screen 48, as shown in FIG.
As shown in 5, multiple images may be included at the same time. In FIGS. 4 and 5, 10A and 10B are microfilms and 1
Reference numerals 6A and 16B denote constant areas output on the print paper 18A.

The fixed area 16A of the microfilm 10A of FIG. 4 includes an image 12C and a part of the image 12D. In addition, a certain area 1 of the microfilm 10B of FIG.
6B includes front and back images 12E, 12e, 12 such as bills.
F, 12f, 12G, 12g, etc. are included.

The black frame 22A in the constant area 16A shown in FIG.
It is detected and stored in the black frame detecting means 66. An appropriate area 16C including a necessary image (for example, 12f) is extracted from the fixed area 16B of FIG. 5 by a trimming means (not shown), and the black frame 22B of the extracted area 16C is detected by the black frame detecting means 66. Stored in memory.

In FIG. 1, 67 is a black frame correction means. The black frame correction means 67 is necessary when a plurality of images are included in the fixed areas 16 (FIG. 7), 16A (FIG. 4) to be output to a printer or the like, or the extracted area 16C (FIG. 5). Select only the image and rewrite the unselected image to black as well as the black frame.

For example, in the case of FIG. 4, two images 12
One of C and 12D, 12C, is used as a selected image, and the area of the image 12D is black. Similarly, in the case of FIG. 5, one image, for example, 12f is set as a selected image, and the regions of other images are made black.
The area thus rewritten to black is stored as a corrected black frame.

As the selected image, an image at a predetermined position in the constant area 16A or the extraction area 16C can be automatically selected. For example, images at the left end, the right end, the upper left corner, the lower left corner, etc. are set as the selected images. To select the selected image, the coordinates on the screen 48 may be input from the keyboard. Further, the image read by the line sensor 52 may be displayed on a display means such as a CRT or a liquid crystal plate, and a selected image may be designated on the display means from a touch panel, a mouse, a keyboard or the like.

As described above, by the first image reading,
The detection of the black frame and the detection of the threshold value D _TH (n) are performed. Then, at the time of the second image reading, the obtained threshold value D _TH (n) is used to perform binarization in the second binarizing means 60. That is, an image near the nth scan line 26 (n) is binarized by using the threshold value D _TH (n), and the threshold value D _TH in the vicinity is sequentially read from the memory according to the image reading area. Read and use.

The binarized output signal is the image processing means 6
8 is input. This image processing means 68 enlarges an image
Various spatial filtering processes such as compression, edge enhancement by differential processing, thinning processing, dither processing, etc. are performed.

The image signal subjected to such image processing is masked in an unnecessary area such as a black frame by the masking means 70, and further frame lines to be described later are added by the frame line joining means 71 to the output means 72. Is output. The black frame used here is a black frame corrected by the black frame correction means 67 so that an unnecessary image is corrected to a black frame. The output means 72 is formed by a printer, for example, and erases the masking range from the image-processed image signal to print out.

If the black frame corrected by the masking means 70 is erased, the outer shapes of the output images 12C and 12f, that is, the frame lines 12C 'and 12f' are also erased. Therefore, the dimensions of the images 12C and 12f become unknown, and the image 12
It is also difficult to see C and 12f.

Therefore, in the present invention, the frame line is detected using the corrected black frame, and the output image and this frame line are overlapped and output. In this embodiment, the detection of this frame line is performed by the frame line detection means 74 in FIG. Various detection methods are possible. For example, the frame line can be detected by spatially filtering the corrected image signal indicating the black frame using a differential filter. Further, a boundary, that is, a frame line may be detected by using a spatial filter that detects a boundary in the horizontal direction and a boundary in the vertical direction in the image signal indicating the black frame. Further, the contour, that is, the frame line may be obtained by sequentially moving the masks on the adjacent boundaries while keeping the center of the 3 × 3 mask on the boundaries.

When the frame line is obtained by using an appropriate algorithm, the frame line joining means 71 adds this frame line to the masked image and causes the output means 72 to print it out.
As a result, as shown in FIGS. 4 and 5, the black frame disappears and the image to which the frame lines 12C 'and 12f' of the selected images 12C and 12f are added is printed out.

Next, the operation will be described with reference to FIG. When performing the first image reading (scan) (step 10
0), first, the order m of scanning lines is initialized to 1 (step 102). Then, it is determined whether or not this order m matches the black frame detection scanning line 26 (step 10).
4). That is, since the black frame detection scanning line 26 appears at regular intervals, for example, every 16 scanning lines, when m is an integer multiple of 16I (where I is an integer), the black frame detection scanning line 26 is m ≠ 16I. The scan lines of are for histogram detection.

Therefore, in the first m = 1 to 15, m ≠ 1
Since it is 6I, the histogram is obtained from the scanning lines in the meantime (step 106), and the threshold value D _TH (1) is calculated and stored (step 108). When m = 16, the scanning line 26 (1) for black frame detection is the first one, so the threshold value D _TH (1) obtained immediately before is used for binarization by the first binarizing means 56. (Step 110),
Further, a black frame is detected and stored (step 11).
2). When the above operation is repeated and the processing is completed for the entire area of the image (steps 114 and 116), the second scan is started (step 118).

Prior to the second scan, step 1
Select one or more images from the black frame obtained in 12,
Black frame correction processing is performed to rewrite other than the selected image into black (step 113). This black frame correction processing is performed by the procedure shown in FIG. First, after detecting the black frame (step 11)
2) It is determined whether or not a plurality of images are included (step 113A).

If a single image is included, the black frame need not be modified. If a plurality of images are included, only the required image is selected (step 113B), the other image range is rewritten to black (step 113C), and the black frame is corrected so that the rewritten range is included in the black frame. Perform (step 113D) and store in memory.

When the correction image of the black frame is finished in this way, the boundary between the black frame and the output images 12C and 12f, that is, the frame line 12
C ′ and 12f ′ are obtained by the frame line detecting means 74 and stored (step 113E).

In the second scan, the threshold value D _TH obtained from the histogram in step 108 is used to scan the image twice.
The image is binarized (step 120), and image processing is performed using the binarized image (step 122). Further step 1
The black frame range obtained in step 12 and corrected in step 113 is masked and erased (step 124). Then, the frame lines 12C 'and 12f' are added to the masked image by the frame line joining means 71 (step 12).
6) Then, the image to which this frame is added is printed out (step 128).

In the above embodiment, when a plurality of images are included in the print output range, a part of the images is selected and the other images are erased as a black frame. All the images may be output without selecting the images. Further, in this embodiment, the frame line is obtained from the black frame and this frame line is added to the output image, but the present invention may leave a part of the black frame as the frame line. For example, black pixels of a black frame may be sequentially rewritten to white pixels on the image side to leave only a black frame having a constant width (for example, 1 mm width), and this may be used as a frame line.

[0042]

As described above, according to the first aspect of the present invention, the black frame is detected and masked, while the black frame is used to obtain the frame line of the image and the frame line is added to the output image. , And can be output to a printer or the like by adding a frame line to the image, so that the image range is clear and easy to see. The invention according to claim 2 also provides a device which is used directly for carrying out this method.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

[Fig. 2] Operation flow chart

[Fig. 3] Detailed operation flow chart of black frame correction

FIG. 4 is a diagram showing a print output example according to the present invention.

FIG. 5 is a diagram showing another example of print output.

FIG. 6 is a diagram showing a histogram.

FIG. 7 is an explanatory diagram of the relationship between microfilm and print output.

[Explanation of symbols]

 10A, 10B, 30 Micro film 12, 14 image 12C, 12f Selected image 12C ', 12f' Frame line 16, 16A, 16B Print output area 16C Extraction area 18, 18A, 18B, 20 Print paper 22, 22A, 22B Black frame 52 Line sensor as image reading means 56 First binarizing means 66 Black frame detecting means 67 Black frame correcting means 68 Image processing means 70 Masking means 71 Frame line joining means 72 Output means 74 Frame line detecting means

Claims (2)

[Claims] 1. A method for reading out a certain area of a microfilm 2
In the method of detecting a black frame from the array of pixels indicated by the image signal obtained by binarization and erasing the black frame and outputting, a frame line of the output image is obtained using the detected black frame, and the frame line and the black frame are obtained. A masking method for a microfilm reader, which is characterized in that an erased image is superposed and outputted. 2. A black frame is detected from an image reading means for reading a certain area of a microfilm, a binarizing means for binarizing the output of the image reading means, and an array of pixels indicated by the binarized image signal. In the masking device of the microfilm reader, which comprises a black frame detecting means for erasing and a masking means for erasing the detected black frame, a frame line calculating means for obtaining a frame line of an output image from the black frame detected by the black frame detecting means,
A masking device for a microfilm reader, comprising frame line joining means for adding the frame line to an output image from which the black frame has been erased by the masking means.