JPH10134071A - Picture recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture recording/reproducing device which speedily recognizes characters, which efficiently files picture data and which efficiently retrieves and reproduces picture data. SOLUTION: An ID recognition means 10 recognizes ID information I by character pattern matching from a picture to which ID information I taken by the image pickup device 9 of CT and MRI is added. A filing means 60 files recognized ID information I' obtained by recognition as retrieval information in a storage means 65 in accordance with picture data. Recognized ID information I' recognized by the ID recognition means 10 is outputted by a picture reproduction means 80 with a reproduced picture and an observer recognizes the presence or absence of errors in a recognized result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording / reproducing apparatus, and more particularly, to a subject such as a medical image including characters such as data for photographing and a patient in addition to an image for medical diagnosis. The present invention relates to an image recording / reproducing apparatus for recognizing characters from image data carrying an image including character information in addition to the image, and filing the image data and reproducing / outputting the image.

[0002]

2. Description of the Related Art Conventionally, a subject such as a human body is subjected to CT, MR, or the like.
The image data of a medical image obtained by photographing with I or the like is subjected to appropriate image processing for each image data, and then the image is reproduced and recorded. Based on these image data, the image of the subject is Is a recording material such as a photosensitive material, C
An image recording / reproducing system for outputting a visible image to an RT or the like has already been put to practical use.

[0003] In these image recording / reproducing systems, images and the like taken by various modalities (such as CT and MRI imaging methods and apparatuses) are stored. Searching and reproducing image data has been performed.

Search information used for image data search of medical images is generally ID information such as a patient name, an ID number, an imaging date, a date of birth, and the like. Image data is stored in association with these ID information. I have. It should be noted that these pieces of ID information are usually given when a medical image is taken, and include kanji,
Kana, English letters, numbers, symbols, etc. (hereinafter collectively referred to as "characters").

Conventionally, as a method for recognizing characters from an image including characters, there is a method called template matching in which a template of a character to be recognized (candidate character) is prepared and compared with the characters in the image. Are known. In this method, the recognition target area on the image and all templates are sequentially matched, and the template with the best matching result is determined as the recognition result. If no recognition target area is specified, the recognition on the image is performed. The target area is sequentially shifted, and matching is performed on the entire image.

However, when trying to recognize a character from an image in which a pattern and a character are mixed, a character overlapping the pattern is likely to be erroneously recognized. In addition, even if it is a normal character, for example, between characters similar to each other (hereinafter referred to as similar characters) such as I (uppercase eye), l (lowercase el), and 1 (numeral 1), originally, Since there is not much difference between the evaluation values at the time of matching, erroneous recognition is likely to occur, and the reliability of the recognition result is low.

[0007] In these cases, if a file is filed with the incorrect recognition result associated with the image data, it becomes an obstacle when the user tries to retrieve later.

Therefore, a character recognition apparatus which issues a warning to a user for a character recognized by the present applicant as having a possibility of erroneous recognition during character recognition and requests confirmation or correction of the character as a result of recognition. An image recording / reproducing system employing this character recognition device has been proposed (Japanese Patent Application No. 8-172617).

[0009]

However, the above-described character recognition device needs a judgment means for judging whether or not the character recognition result is suspicious, a warning means for giving a warning to the user, and the like. Therefore, there is a problem that the cost of the apparatus is high, and a warning is issued only when the character recognition result is suspicious, and the user needs to confirm or correct the operation, which is troublesome and inefficient in work efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an image recording / reproducing apparatus capable of quickly recognizing characters, efficiently performing filing processing of image data, and efficiently retrieving and reproducing image data. The purpose is to provide.

[0011]

An image recording / reproducing apparatus according to the present invention stores image data carrying an image including character information photographed by various devices in association with the character information and reproduces the image. In the image recording and reproducing apparatus, a character recognizing means for recognizing the character information from the image, a filing means for storing the character information obtained by recognition by the character recognizing means and the image data in association with each other, Image reproducing means for reproducing and outputting the character information, wherein the image reproducing means outputs character information obtained by recognition by the character recognizing means together with the image.

Here, the image data stored by the filing means may be image data carrying original images photographed by various devices, or may be obtained by subjecting the original image data to predetermined image processing. It may be processed image data. Similarly, the image reproduced and output by the image reproducing means may be an original image or a processed image.

[0013] The "character information obtained by the character recognition means" refers to a recognition result recognized by the character recognition means. If the character recognition by the character recognition means is correctly performed, the character information is obtained. The character information included in the image matches the character information. If there is an error in character recognition by the character recognition unit, the character information does not match the character information included in the image.

The "image reproducing means" refers to a means capable of displaying a visible image, such as a printer or a CRT.

[0015] The image reproducing means may arrange the character information included in the image together with a recognition result obtained by the character recognizing means, and output the character information separately from the image. Further, the image reproducing means may enlarge and output the character information obtained by recognition by the character recognizing means and the character information included in the image.

It is preferable that the image recording / reproducing apparatus further includes a correcting means for correcting character information obtained by the character recognizing means in response to an external instruction.

The image may be a medical image, and the character information may be ID information for identifying a subject in the image.

Here, the image means a mixture of characters and pictures.

[0019]

Since the image recording / reproducing apparatus of the present invention outputs the result of character recognition by the character recognizing means together with the image at the time of image reproduction and output by the image reproducing means, the observer can confirm whether there is a recognition error by the character recognizing means. It can be performed.
Therefore, even if the file is filed with the erroneously recognized character information, it is not impossible to search for the image data later. Further, since there is no need to provide a means for determining and warning the possibility of erroneous recognition of character recognition, the apparatus can be configured at low cost. In addition, since the work is not interrupted during the recognition due to a warning of the possibility of misrecognition, the character recognition and the data filing process can be performed efficiently.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the image recording / reproducing apparatus of the present invention will be described with reference to the drawings. In the present embodiment, an image recording / reproducing apparatus particularly for medical images will be described as an example.

The medical image recording / reproducing apparatus 100 shown in FIG.
An original image data S carrying an original image captured by various imaging devices 9 such as CT and MRI is input, and an ID recognizing means (character recognizing means) 10 for recognizing ID information I attached to the original image is provided. An input unit 50 for inputting device information relating to a device that has generated the image data S to the ID recognizing unit 10 when the image data S is input, a formatter 70 for performing predetermined signal processing on the original image data S, An image reproducing means 80 such as a printer or a CRT for reproducing image data (hereinafter, referred to as processed image data) S ′ subjected to predetermined signal processing by the formatter 70, and the original image data S and the processed image data S ′ I obtained by recognition by the ID recognition means 10
Filing means 60 for filing in storage means 65 in association with D information I '(hereinafter referred to as recognition ID information I').
Instruction input means 90 for the user to give a correction instruction when the recognition ID information I 'has an error, and correction means 95 for correcting the recognition ID information I' according to the instruction of the instruction input means 90.
Consists of

Here, the formatter 70 divides a single film into four small areas different from each other, for example.
The original image conforms to various formats for reproducing the image, such as a format for printing four different images in each area in a reduced size and a format for printing one large image on a single film as it is. This is to process data.

As shown in detail in FIG. 2, the ID recognizing means 10 receives the original image data S, binarizes the original image based on the original image data S, and generates a binarized image. An image generating means 30, a dictionary 35 having a character font template 5 unique to various devices for generating an original image, character regions and character intervals in an image defined for each device for generating an original image, and the like. And a character font template 5 corresponding to the device information input from the external input means 50 is selected from the dictionary 35, and the character position information corresponding to the device information is stored in the character position. Using the template 5 selected by the selection unit 45, the selection unit 45 selected from the information storage unit 38 and the binarized image generated by the binarized image generation unit 30, position Comprising characters from recognizing matching means 40. By character pattern matching based on the distribution. The binarized image generating means 30 includes, for each pixel of the original image, a calculating means 32 for calculating a difference between a maximum value and a minimum value of a pixel density in a predetermined neighborhood range of the pixel;
Binarizing means for binarizing each pixel by extracting a contour of an image by comparing the density difference obtained by the step 32 with a predetermined threshold value
Consists of 34. Here, the template of the dictionary 35 is a binarized hollow character template 5 corresponding to a font of a character unique to various devices.

The operation of the image recording / reproducing apparatus 100 according to the present invention will be described below.

The image picked up by the image pickup device 9 is digitized and input to the image recording / reproducing device 100 as original image data S. At this time, the device information that generated the image is also input from the input means 50 at the same time. Image recording and playback device 100
First, in the ID recognition device 10, input means
Based on the device information input from 50, the ID information I attached to the image is recognized. This ID recognition is performed as follows.

In the binarized image generating means 30, the difference between the maximum value and the minimum value of the density of the input original image data S in a predetermined neighborhood range of each pixel of the image is first calculated in the calculating means 32. Can be For example, the target pixel is 2 × 2
When the pixel is located at the lower left of the pixel mask, the maximum value and the minimum value of the gradation density (original image data S) in a total of four pixels in the 2 × 2 pixel mask (predetermined neighborhood range) are obtained, and this is determined as the pixel of interest. And the density difference. Naturally, the range of 2 × 2 is an example, and it is not necessary to limit to this. Next, in the binarizing means 34, the density difference obtained by the calculating means 32 is compared with a predetermined threshold value. For example, when the density difference is larger than the threshold value, it is set to "1", and when it is small, it is set to "0". The pixel of interest is binarized. By performing this binarization for each pixel in the image, a portion where the density difference between neighboring pixels in the image is large, that is, the outline of the image is extracted, and a binarized image B is generated from the original image A ( (Fig. 3). Usually, since the density difference between the character and the surrounding image is large, the outline of the character is extracted.

The outline of the image is extracted by using a primary differential filter, a Laplacian filter, etc., and the pixels of the extracted outline portion are set to "1", and the pixels other than the outline portion are set to "0", and are binarized. , It is possible to generate a binarized image in which the contour is extracted, similar to the binarized image B generated in the second embodiment.

Thereafter, a template corresponding to the device information input by the external input unit 50, that is, a template 5 corresponding to the character font used by the device that generated the original image A, is selected from the dictionary 35 by the selection unit 45. At the same time, the character position information corresponding to the device information is selected from the character position information storage means 38, and the matching means 40 performs matching using the template 5 on the character area 6 of the binarized image B. (FIG. 4).

Since the character position information unique to various devices includes information on the character space in addition to the character region 6, the character space that can be assigned to the character region, that is, the center position of the character to be matched is clear. It suffices that the matching is performed by matching the center position of the character with the center position of the template. Therefore, the template 5 may be moved by the character interval from the matching start position of the character region by the character interval for matching. As a result, the processing can be performed at a higher speed than in the case where the matching is performed by shifting each pixel.

Further, since it is only necessary to match a selected number of templates, that is, only a very limited number of templates, high-speed identification becomes possible.

Here, a conventional general recognition method using template matching will be described. When the image pattern f and the template pattern g have a size and a positional relationship as shown in FIG. 5, respectively, the similarity between the image pattern f at the image point (m, n) and the template pattern g is evaluated as follows. Expressed by a function.

[0032]

(Equation 1)

Here, usually, R (m, n) is called a cross-correlation coefficient, and a region D has a range of (i, j) satisfying | im | <M / 2, | jn | <N / 2. It is. By moving the template on the image, the similarity between the image and the template is sequentially determined based on the cross-correlation coefficient R described above. A larger value of the cross-correlation coefficient R indicates that a figure closer to the template exists around the image (m, n), that is, the image and the template have a stronger correlation, and the image and the template are completely matched. Takes a value of 1 and a value of 0 when there is no match. Normally, the one having the largest cross-correlation coefficient R is regarded as the recognition result. However, the above-described template matching method requires calculation of the square and the square root as shown in the above equation, and thus has a disadvantage that the amount of calculation is large and recognition takes time.

However, in the present ID recognizing means, since matching is performed on the binarized image, a similarity evaluation function R ′ based on exclusive product-sum (exclusive or) can be used, and the calculation time is further reduced. Can be shortened. At this time, the image pattern f at the point (m, n) on the image
And the similarity evaluation function R ′ (m, n) of the template g

[0035]

(Equation 2)

## EQU1 ## However, the area D is
| im | <M / 2, | jn | <N / 2 (i, j). Contrary to the case of R described above, the template having the smallest R ′ is determined as the recognition result.

In the above-mentioned binarization, "1",
Instead of “0”, the sum may be binarized to “1” or “−1” and a simple sum of products value may be used for the evaluation function. The evaluation function R "(m, n) in that case is

[0038]

(Equation 3)

And the template having the largest R ″ is the recognition result.

Further, IDs such as a patient name, an ID number, a photographing date, etc.
When it is desired to recognize only specific ID information, for example, only an ID number, in an image to which information has been added, only characters used for the ID number are used as templates, and the ID number is assigned in the character area. It is also possible to adopt a form of matching only for the area (the same applies to other ID information).

As described above, the recognition ID information I 'obtained by the recognition by the ID recognition means 10 is the original image data S'.
Along with the filing means 60 and the formatter 70. In the formatter 70, predetermined signal processing is performed on the original image data S to generate processed image data S ', and a visible image is reproduced in the image reproducing means 80 based on the processed image data S'. At this time, the ID together with the visible image
Recognition means 10 outputs recognition ID information I 'obtained by recognition. "Along with the visible image" means the recognition ID
When the information I ′ is output by a printer, the visible image is printed on a recording medium on which the visible image is printed,
When a visible image is displayed on a CRT, it means that the image is displayed on a screen displaying the visible image. Further, the filing means 60 associates the recognized ID information I 'recognized by the ID recognizing means 10 with the original image data S and / or the processed image data S' processed by the formatter, and filing them into the storage means 65. I do. The filed image data S and S ′ can be searched at all times, and the search uses the ID information I ′ stored in association with the image data as search information.

The search information may be associated with the image data by all or a part of the recognition ID information I 'obtained by recognition. For example, when there are a plurality of pieces of ID information such as a patient name, an ID number, and a radiographing date, each piece of information may be associated so as to be search information, or one of these may be selected. For example, filing may be performed by associating only ID numbers as search information. Furthermore, it is also possible to associate as search information using only the first few characters of each ID information composed of a plurality of characters.

The “recognition ID information I ′ obtained by the recognition by the ID recognition means” is the ID information I added to the image when the recognition by the ID recognition means 10 is correctly performed. If an erroneous recognition occurs during character recognition, the ID information is different from the original ID information I. Original ID information I
Regardless, since filing is performed using recognition ID information I ′ obtained as a result of recognition, image data may be filed as search information using erroneously recognized characters as they are. Usually, in such a case, there is an adverse effect such that image data cannot be searched for later using the original ID information I. However, in the present image recording / reproducing apparatus, the recognition ID information I ′ is output to the image reproducing means 80 at the time of outputting a visible image, so that the observer can confirm the recognition result, that is, the registered search information, and Problems such as the inability to search can be avoided.

When the image reproducing means 80 is a printer, as shown in FIG. 6A, the recording medium 1 stores ID information I 'obtained by the image recording and reproducing apparatus 100 in addition to the image 2. Printed.

Further, as shown in FIG. 6B, the area to which the ID information I is added in the image and the ID information I ′ obtained by the recognition by the image recording / reproducing apparatus 100 are separated from the image 2 separately. You may make it expand and display. Thus, both I
By arranging and enlarging the D information I and I ', if there is an error in the information registered and recognized in the image recording / reproducing apparatus 100, this error can be easily found. If the observer finds a mistake in recognizing the ID information,
By inputting a correction instruction from the instruction input means 90,
The registration information can be corrected by the correction means 95.

The ID recognizing means is not limited to the above-mentioned form, but may be any form. In the above embodiment, the input means 50 for inputting information about the image pickup apparatus is provided. However, the ID recognizing means is provided with a judging means for judging the image configuration (see Japanese Patent Application No. 8-179344), and characters are added. If the extracted region is extracted and matching is performed for all templates included in the dictionary with respect to this region, the input means as described above is not required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an image recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram showing a configuration of an ID recognizing unit included in the image recording / reproducing apparatus of the present invention.

FIG. 3 is a diagram showing images before and after binarization processing;

FIG. 4 is a view for explaining a state in which a template is moved by character intervals at the time of pattern matching to perform matching;

FIG. 5 is a diagram illustrating a character pattern matching method.

FIG. 6 is a diagram showing an image reproduced and output by the image recording / reproducing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording medium 2 Reproduction image 5 Template 9 Medical imaging device 10 ID recognition means (character recognition means) 30 Binary image generation means 32 Density detection means 34 Binarization means 35 Dictionary 38 Character position information storage means 40 Matching means 45 Selection means 50 Input means 60 Filing means 65 Storage means 70 Formatter 80 Image playback means 90 Instruction input means 100 Image recording and playback device

Claims (5)

[Claims] 1. An image recording / reproducing apparatus for storing image data carrying an image including character information photographed by various devices in association with the character information, and reproducing the image. A character recognizing means for recognizing; a filing means for storing character information obtained by recognition by the character recognizing means in association with the image data; and an image reproducing means for reproducing and outputting the image; An image recording / reproducing apparatus, wherein the reproducing means outputs character information obtained by recognition by the character recognizing means together with the image. 2. The method according to claim 1, wherein the image reproducing unit arranges the character information included in the image together with a recognition result obtained by the character recognizing unit and outputs the character information separately from the image. 2. The image recording / reproducing apparatus according to claim 1, wherein: 3. The image reproducing device according to claim 2, wherein the character information obtained by the character recognizing device and the character information included in the image are enlarged and output. Item 3. The image recording / reproducing device according to Item 2. 4. The image recording / reproducing apparatus according to claim 1, further comprising correction means for correcting character information obtained by the character recognition means in response to an external instruction. . 5. The image recording / reproducing apparatus according to claim 1, wherein the image is a medical image, and the character information is ID information for identifying a subject of the image.