JP3767670B2 - Image transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image transmission apparatus such as a facsimile apparatus, and more particularly to a technique for transmitting a clear character image.
[0002]
[Prior art]
In the field of image transmission apparatuses such as conventional facsimile apparatuses, when a scanned image of a document on which thin characters or small characters written with a pencil are written is transmitted, it is difficult to read the received character image on the receiving side. There was a problem that reading errors occurred. For this reason, when sending a document containing such difficult-to-read characters, the operator manually changes the image density and image resolution settings of the transmission image before transmission, and sends a transmission image according to the changed conditions. Printed out and confirmed whether the receiving side can identify the character image. At this time, the operator has to pass the document many times and print out the transmission image again until the optimum image is obtained, which is inconvenient. Therefore, in this type of apparatus, the image data of the read original is input to the character recognition unit before transmission, and the portion that can be recognized as the character in the image data is converted and stored into the character code of the character font, and then the image data is again processed. In some cases, the character image in the read image data is automatically corrected to a clear image by converting to (for example, see JP-A-8-107491).
[0003]
[Problems to be solved by the invention]
However, in the conventional image transmission apparatus as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-107491, the character image in the image data has a defect such as a blurred character or a broken character. Since images that cannot be recognized are transmitted without being corrected, there is a problem that these character images cannot be read on the receiving side.
[0004]
The present invention has been made in order to solve the above-described problems. When thin characters or small characters that are difficult to recognize as characters are described in a document for transmission, the image density of the transmission image is manually set. The text image can be automatically corrected without changing the image resolution setting or passing the document many times and reprinting the confirmation image. An object of the present invention is to provide an image transmission apparatus capable of transmitting a clear image that can be easily read.
[0005]
[Means for Solving the Problems]
To accomplish the above object, an image transmission apparatus having an image reading means for reading an image, and storage means for storing the image data read by the image reading means, said storage means, predetermined A read image storage unit that stores image data of a document read at a resolution of 1, and a corrected image data storage unit that converts the image data into image data of a resolution corresponding to a transmission mode and stores the image data. Character recognition means for recognizing characters in the image data stored in the post-image data storage unit, determination means for determining the character recognition rate identified by the character recognition means, and character recognition rate determined by the determination means When comparing means for comparing the preset to have set values, the comparison means compares the results of the character recognition rate is set in advance When the image recognition rate is lower than the set value, the corrected image data is converted at a higher resolution until the character recognition rate is equal to or higher than the set value, and the converted image data is converted into the corrected image data storage unit. Image correction means for correcting the image data by repeating the operation of storing the image data .
[0006]
In the above configuration, the read image is stored in the storage means, and before transmitting the image, the characters in the image data are recognized by the character recognition means, and the recognition rate is determined by the determination means. The setting value set in advance is compared with the comparison means. Based on this result, the image data stored in the storage unit is corrected by the image correction unit as necessary. Thereby, when a thin character or a small character that is difficult to be recognized as a character is written on the transmission document, for example, the image density and the image resolution are automatically changed, and an appropriate image can be transmitted. . Accordingly, there is no need to manually change the image density and image resolution settings of the transmission image, or repeatedly pass the document and print out the confirmation image again.
[0007]
In the above comparison result, when the character recognition rate is lower than a preset value, the image correction means may be operated. Further, the correction operation by the image correction unit and the comparison operation by the comparison unit may be repeated until the character recognition rate becomes a value equal to or higher than the set value. The image correction means can change the resolution of the image data. Further, the set value may be changeable.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the appearance of the image transmission apparatus according to the present embodiment. The image forming apparatus according to the present embodiment is a facsimile that transmits image data of a read original to a communication apparatus of a partner via a public line or the like. The facsimile 1 has an operation panel 10 for instructing setting of various modes of the apparatus and start of transmission on the front surface of the facsimile 1. Behind the operation panel 10 is a document feed tray 21 for conveying a document to be read to an image reading unit 32 (see FIG. 3) provided inside the apparatus, and for discharging the read document. Original paper discharge tray 22 and a recording paper discharge tray 23 for discharging the recording paper on which the received image data is recorded are provided side by side in the front-rear direction. Is provided with a recording paper supply tray 24.
[0009]
Next, the configuration of the operation panel 10 will be described with reference to FIG. On the right side of the operation panel 10, a start key 11 for instructing transmission of a document, a stop key 12 for instructing transmission stop, a copy key 13 for instructing copying of a document, a character document, A character manuscript correction key 14 for instructing the mixed picture manuscript to enter the character correction mode, a character / picture mixed manuscript correction key 15 and a numeric keypad 16 for inputting the destination facsimile number are provided. On the left side of these keys 11 to 16 are a one-touch dial key 17 for registering a FAX number, a display unit 18 for displaying various messages, a function key 19 for instructing a desired function to the apparatus, and a transmission image. A mode setting key 20 for setting the mode of the resolution is provided.
[0010]
FIG. 3 shows a block diagram of the control system of the facsimile 1. The facsimile 1 has a main control unit 31 that controls the entire apparatus. The main control unit 31 includes an image reading unit 32 (image reading unit) for reading an original, a read image data storage unit 33 (storage unit) for storing image data of the read original, and characters in the image data. A character recognition unit 34 (character recognition unit) made up of OCR or the like for image recognition, an image processing unit 35 (image correction unit) for performing image processing such as resolution and density correction on image data, and image processing The corrected image data storage unit 39 (storage means) for storing the image data corrected by the unit 35, the transmission / reception unit 36 for transmitting / receiving the image data, the test print of the image data for transmission, and the received image data Print unit 37 for printout, mode of transmission resolution such as standard, fine, super fine Mode switching means 38 (corresponding to the mode setting key 20 shown in FIG. 2) and image correction instruction means 40 (indicated in FIG. 2) for instructing to enter various image correction modes such as a character correction mode. Character character correction key 14 and character / picture mixed document correction key 15), and character font data storage unit 41 storing character font data used for character recognition in character recognition unit 34 are connected.
[0011]
FIG. 4 shows a transmission process of the facsimile 1 according to the present embodiment. When the character document correction key 14 or the character / picture mixed document correction key 15 is pressed during facsimile transmission, the main control unit 31 switches the device mode to the character correction mode. Then, a reading document is set on the document feed tray 21 by the operator (# 1), a transmission resolution mode selection instruction (hereinafter referred to as a transmission mode) using the mode setting key 20 (# 2), and a numeric keypad. After the destination facsimile number is input using the 16 or one touch dial key 17 (# 3), when the start key 11 is pressed (# 4), the main control unit 31 causes the drive unit (not shown) to An instruction is given, and the documents set on the document feed tray 21 are taken into the apparatus one by one and conveyed to the image reading unit 32. Next, the main control unit 31 reads the original with the highest resolution by the image reading unit 32 and stores this image data in the read image data storage unit 33 (# 5). The original image data stored in the read image data storage unit 33 is read, converted into image data having an image resolution corresponding to the transmission mode, and stored in the corrected image data storage unit 39 (# 6). The image data is input to the character recognition unit 34, and the character recognition rate in the character recognition unit 34 is calculated (# 7). As a result, when the recognition rate is equal to or smaller than a preset value (NO in # 8), the main control unit 31 determines that the character cannot be read on the receiving side, and increases the transmission resolution by one level (# 9). ), The image processing unit 35 corrects the image data to image data one level higher, and stores the corrected image data in the corrected image data storage unit 39 (# 10). If the resolution does not reach the maximum value (NO in # 11), the corrected image data stored in the corrected image data storage unit 39 is read, and this image data is input to the character recognition unit 34. The character recognition rate is calculated again (# 7). When the recognition rate exceeds the set value (YES in # 8), the main control unit 31 determines that the character can be read on the receiving side and determines the transmission resolution (# 19). Then, the image data stored in the corrected image data storage unit 39 is read, transferred to the image processing unit 35, and subjected to various image processing (# 20). (# 21).
[0012]
When thin characters or small characters that are difficult to recognize as characters are written on the original for transmission, the recognition rate for characters in the image data is low. Therefore, the main control unit 31 increases the transmission resolution by the processes of # 7 to # 11 until the character recognition rate exceeds the set value in the comparison process of # 8. For example, if this device has three types of transmission resolutions of standard, fine, and super fine, and the operator has selected to transmit in standard, the main control unit 31 sets the recognition rate to the set value. Increase the resolution with fine, super fine until it exceeds. When the resolution reaches the maximum value (YES in # 11), the main control unit 31 determines the transmission resolution to the maximum value (# 12) and reads the image read from the corrected image data storage unit 39. After various image processing is performed on the data by the image processing unit 35 (# 13), the image data is transferred to the printing unit 37 and printed out at the highest resolution (# 14). When the operator views the printed image and determines that the character can be read and presses the start key 11 (YES in # 15), the main control unit 31 performs the image processing of # 13. The transmitted image data is transmitted to the destination apparatus by the transmission / reception unit 36 (# 16). On the other hand, when the operator determines that the character cannot be read and presses the stop key 12 (YES in # 17), the main control unit 31 stops transmission to the counterpart device (#). 18). Note that the character recognition rate calculation process in the character recognition unit 34 by the main control unit 31 in # 7 corresponds to the determination means in the claims. The process of comparing the character recognition rate and the set value in # 8 corresponds to the comparison means in the claims.
[0013]
Here, FIG. 5 illustrates an example of the relationship between the transmission resolution and the character recognition rate. For example, when “A”, “I”, “U”, “E”, “O” are recognized as the characters of the original of the read image, and the transmission resolution shown in FIG. The characters “a” and “o” are not recognized and the character recognition rate is 60%. However, as shown in FIGS. 5B and 5C, as the transmission resolution increases to fine and super fine, the characters Is recognized accurately, and the character recognition rate is improved.
[0014]
As described above, according to the facsimile 1 according to the present embodiment, the recognition rate of characters in the image data is compared with a preset setting value, and the image data is corrected according to the comparison result. As a result, if the original for transmission contains thin or small characters that are difficult to recognize as characters, you can manually change the image resolution setting of the transmission image, or pass the original over and over again. Thus, the image data for transmission can be automatically corrected without reprinting the confirmation image. This makes it possible to transmit a clear image in which a character image can be easily read, and to improve the operability of the apparatus.
[0015]
The present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, the corrected image is automatically transmitted when the character recognition rate exceeds the set value. However, when the character recognition rate exceeds the set value, it is the same as the image to be transmitted. The thing may be printed out so that the operator can confirm it before transmission, or the degree of character recognition may be displayed on the display unit 16 to wait for the operator's judgment. In the above embodiment, the confirmation image is printed out when the transmission resolution reaches the maximum value. However, the confirmation image is displayed on a display such as a CRT connected to the apparatus. May be. Thereby, recording paper can be saved. Furthermore, in the above embodiment, when the character recognition rate is smaller than the set value, only the resolution of the transmission image is automatically changed. However, the density and the number of gradations may be automatically changed together with the resolution. Or only the number of gradations may be automatically changed. In the above embodiment, the character recognition rate of the entire image data for transmission is determined. However, the character recognition rate of the entire image data is estimated by determining the character recognition rate of a part of the image data for transmission. May be. Furthermore, in the above embodiment, the initial value of the transmission resolution is set to the transmission resolution corresponding to the transmission mode set by the mode setting key 20, but the transmission resolution requested by the partner machine is set through the protocol with the partner machine after the start key is turned on. The transmission resolution may be obtained as an initial value.
[0016]
【The invention's effect】
As described above, according to the present invention, the character recognition rate in the image data of the read transmission original is compared with a preset setting value, and the image data is corrected according to the comparison result. Therefore, if the original contains thin or small characters that are difficult to recognize as text, you can manually change the image density and image resolution settings of the transmitted image, The image data for transmission can be automatically corrected without reprinting the confirmation image. This makes it possible to transmit a clear image in which a character image can be easily read, and to improve the operability of the apparatus.
[0017]
In the above comparison result, when the character recognition rate is lower than a preset value, the above effect can be obtained accurately by operating the image correction means.
[0018]
Further, by repeating the correction operation by the image correction unit and the comparison operation by the comparison unit until the character recognition rate becomes a value equal to or higher than the set value, the thin character or the small character that is difficult to be recognized as a character in the transmission document. When the characters are described, the image data can be automatically corrected until the character recognition rate becomes a value equal to or higher than the set value. As a result, it is possible to transmit image data in which the character recognition rate is greater than or equal to the set value.
[0019]
Further, the character recognition rate of the image data for transmission can be increased by changing the resolution of the image data in the image correction means.
[0020]
Also, by making the set value changeable, the character recognition rate of the image data to be transmitted can be changed according to the image level required by the receiving side.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an appearance of an image transmission apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an operation panel of the image transmission apparatus.
FIG. 3 is a block diagram of a control system of the image transmission apparatus.
FIG. 4 is a flowchart showing a transmission process of the image transmission apparatus.
FIG. 5 is a diagram illustrating a relationship between a transmission resolution and a character recognition rate of the image transmission apparatus.
[Explanation of symbols]
1 Facsimile (image transmission device)
31 Main control unit (determination means, comparison means)
32 Image reading unit (image reading means)
33 Reading image data storage (storage means)
34 Character recognition part (character recognition means)
35 Image processing unit (image correction means)
39 Image data storage after correction (storage means)

Claims (1)

In an image transmission apparatus comprising an image reading means for reading an image and a storage means for storing image data read by the image reading means,
The storage means stores a read image storage unit that stores image data of a document read at a predetermined resolution, and a corrected image data storage unit that converts the image data into image data of a resolution corresponding to the transmission mode and stores the converted image data. Have
Character recognition means for recognizing characters in the image data stored in the corrected image data storage unit ;
Determination means for determining a character recognition rate identified by the character recognition means;
Comparing means for comparing the character recognition rate determined by the determining means with a preset setting value;
When the character recognition rate is lower than a preset value as a result of comparison by the comparison means , the corrected image data is converted with a higher resolution until the character recognition rate is equal to or higher than the preset value. And an image correcting unit for correcting the image data by repeating the operation of storing the converted image data in the corrected image data storage unit .

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