JPH08163367A - Picture processor - Google Patents

Abstract

PURPOSE: To provide the picture processor which obtains a satisfactory picture image of less blur and painting-out with any writing tool. CONSTITUTION: A writing tool discrimination part 13 discliminates the classification of the writing tool, with which characters, graphics, or the like are written, in accordance with the picture image read from a medium to be read, and a filtering switching part 15 selects a picture shaping method (filtering) corresponding to the writing tool discriminated by the writing tool discrimination part 13. Picture shaping means 16 and 17 are selected in accordance with the used writing tool by the filtering switching part 15 and subject the read picture of the medium to be read to the picture shaping processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for optically scanning a medium such as a document or a form to obtain an image image.

[0002]

2. Description of the Related Art Generally, a black pencil or a ballpoint pen is often used as a writing tool to be used when writing characters, figures, etc. on a medium such as a form. By the way, even with the same black color, the density of the drawn lines, the state of the edges, the thickness, etc. are different between the pencil and the ballpoint pen. In some cases, the final image may be adversely affected by applying ().

In order to avoid such a problem, it is necessary to know the type of writing instrument in advance. As a method for this, conventionally, the operator of the apparatus is instructed whether the writing instrument is a pencil or a ballpoint pen. Was going. However, such a method not only increases the burden on the operator, but also has a problem that high-speed processing cannot be performed or an error such as an instruction error is likely to occur.

In order to eliminate such drawbacks of the prior art, an optical character reader as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-112124 has been proposed. With this device, the same writing tool as the one used is used to read the mark written in a predetermined location on the medium to be read with a sensor, and this reading signal is compared with a reference value prepared for each type of writing tool to determine the writing tool. Then, an appropriate optical filter corresponding to the writing instrument is selected, and the image information on the medium to be read such as a form is read through the selected optical filter.

[0005]

However, although the optical character reading device can capture an image image using a suitable optical filter corresponding to the type of writing instrument, the subsequent filtering process for the captured image is performed. Therefore, the best image is not always obtained, which adversely affects the character recognition accuracy.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an image processing apparatus capable of obtaining a good image with less blurring and crushing for any writing instrument. The purpose is to provide.

[0007]

In order to solve the above-mentioned problems, the present invention is a writing instrument for discriminating the type of writing instrument used when writing characters or figures from an image read from a medium to be read. A discriminating means, an image shaping method selecting means for selecting an image shaping method corresponding to the writing instrument discriminated by the writing instrument discriminating means, and a read image of the medium to be read by the image shaping method selected by the image shaping method selecting means; On the other hand, an image shaping means for performing image shaping processing is provided.

[0008]

In the image processing apparatus of the present invention, the writing instrument determining means determines from the image image read from the medium to be read,
The type of writing instrument used when writing characters or figures is discriminated, and the image shaping method selection means selects the image shaping method corresponding to the writing instrument discriminated by the writing instrument discrimination means. The image shaping means performs image shaping processing on the read image of the medium to be read by the image shaping method selected by the image shaping method selecting means. Therefore, it is possible to always perform an optimum image shaping process on the used writing instrument, and it is possible to obtain a good image image with less blurring and crushing.

[0009]

1 is a block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention. As shown in the figure, the image processing apparatus according to the present embodiment includes a scanning unit 11 that reads color image images of three colors of red (R), green (G), and blue (B) from a medium to be read, and a scanning unit 11. The first image storage unit 12 for storing the color image image read by the above, and the type of writing instrument is discriminated from the color image image stored in the first image storage unit 12, and the color image image is binarized. When the writing tool determination unit 13, the second image storage unit 14 that stores the binarized image, and the writing tool determination unit 13 determine that the writing tool is a pencil, filtering for a pencil writing image is performed. If it is judged to be a ballpoint pen, filtering for the ballpoint pen writing image is performed, and if it is judged to be neither a pencil nor a ballpoint pen, filtering is performed. The filtering switching unit 15 for switching so as not to be selected, and the filtering switching unit 15 selects when the writing implement is a pencil, and the pencil filtering unit 16 which performs a filtering process for a pencil writing image and the writing implement is a ballpoint pen. And a ball-point pen filtering unit 17 for filtering the ball-point pen writing image.

FIG. 2 is a view showing the medium to be read 21. As shown in the figure, characters 22 (ABC) are written on the medium to be read 21 with a black pencil or a ballpoint pen.
The ground color of the medium to be read 21 is white. FIG. 3 is a diagram showing scanning directions (main scanning direction 31 and sub-scanning direction 32) when a color image of the medium to be read 21 is read. Further, FIG. 4 is an explanatory diagram of the filtering process. The operation of the embodiment of the present invention will be described below with reference to FIGS.

The scanning unit 11 optically scans the medium to be read 21 in the main scanning direction 31 and the sub-scanning direction 32 shown in FIG. 3 to sequentially read three color images of R, G and B, and the first image is read. The image is stored in the image storage unit 12.

When the scanning unit 11 stores the color image of the medium to be read 21 in the first image storage unit 12, the writing instrument discriminating unit 13 extracts the pixels constituting the character, and the extracted pixels R, The writing instrument is discriminated from the difference in the densities of the G and B values. At this time, the pixel value that is determined to form the character is set to “1” along with the extraction of the pixels that form the character,
The other pixel values are binarized to "0" and stored in the second image storage unit 14.

As a method of extracting pixels forming a character, it is used that the character 22 and the medium to be read 21 have different colors such as black and white, respectively. Specifically, the R, G, and B values are all small values only for pixels that form a black character, so pixels that have all R, G, and B values smaller than a predetermined threshold value are extracted as pixels that form the character. To do.

As a method of discriminating a writing instrument, the fact that the same black pencil and ballpoint pen have different densities of R, G and B is used. That is, a black pencil generally has a lower density than a black ballpoint pen (R,
The G and B values are large).

When the writing implement discriminating unit 13 completes the discrimination of the writing implement and the binarization of the color image, the filtering switching unit 15 performs the pencil filtering when the writing implement is determined to be a pencil based on the discrimination result of the writing implement. Part 1
6 is connected, and the binarized image stored in the second image storage unit 14 is subjected to optimum filtering processing for the pencil writing image and output. When it is determined that the writing instrument is a ballpoint pen, the ballpoint pen filtering unit 17 is connected, and the binary image stored in the second image storage unit 14 is optimal for the ballpoint pen writing image. Filter and output.
When it is determined that the writing instrument is neither a pencil nor a ballpoint pen, the filtering process is not performed and the second binary image image is output as it is.

Next, the filtering process in this embodiment will be specifically described. For each pixel on the binary image image of the medium to be read stored in the second image storage unit 14 described above, scanning is performed so that the target pixel (pixel of interest) is centered in a window of 3 × 3 pixels. Regarding the 9 pixels at this time, if the number of pixels having the value “1” is 5 or more, the value of the pixel of interest is set to “1”, and if it is less than 5, it is set to “0”. At this time, a filter for pencils that weights the pixel of interest three times is used, and a filter that does not weight the pixels is used for ballpoint pen. For example, when the state of the window of 3 × 3 pixels is as shown in FIG. 4A, the value of the pixel of interest is “0” but the total number of “1” is 5, so the pencil filtering is performed. , The target pixel value is “1” in both the ballpoint pen filtering. Also, in the case shown in FIG. 4B, the pixel value of interest is “1” in both the pencil filtering and the ballpoint pen filtering. On the other hand, in the case of FIG. 4C, since the total number of "1" is 4, the pixel value of interest is "0" when the writing tool is a ballpoint pen, but when the writing tool is a pencil. Is 3 times the weight because the value of the pixel of interest is "1""
The total number of 1's is 6, and the pixel value of interest is "1".

By such a filtering process, it becomes possible to perform appropriate filtering according to the type of writing instrument,
It is possible to satisfactorily restore the blurring or crushing of a character or graphic image.

As described above, the case where the writing instrument is a black pencil and a ballpoint pen has been described in the present embodiment, but the present invention is not limited to this, and a writing instrument such as a felt-tip pen may be used. Further, as a method of extracting the pixels forming the character, the pixels forming the character are extracted from the difference in the R, G, B values of the color image by utilizing the difference in the colors of the character 22 and other parts. However, the present invention is not limited to this, and the writing instrument determination method uses a difference in the R, G, and B value densities of the curler images of the pencil and the ballpoint pen.
In any case, for example, differences in values such as hue (H), saturation (S), and lightness (V) may be used, or a monochrome image may be used instead of a color image.

Further, in the present embodiment, the case where the filtering for pencil writing is performed when writing with a pencil and the filtering for ballpoint pen writing is performed when writing with a ballpoint pen has been described. May be output as it is. Further, although the method of using the window of 3 × 3 pixels has been described as the filtering method in the present embodiment, other suitable filtering processing may be performed, for example, by a thickening processing, a thinning processing, or a smoothing method. Good.

The output of the image processing apparatus according to the present invention can be used by connecting it to a character recognition apparatus or the like. In this case, the input image is filtered for each writing tool to improve the crushing and blurring of characters. Since it can be restored, the character recognition accuracy can be improved.

[0021]

As described above in detail, according to the present invention, from the image read from the medium to be read,
Writing instrument discriminating means for discriminating the type of writing instrument used when writing characters or figures, image shaping method selecting means for selecting an image shaping method corresponding to the writing instrument discriminated by the writing instrument discriminating means, and the image shaping method Since it is configured to include an image shaping unit that performs an image shaping process on the read image of the medium to be read by the image shaping method selected by the selection unit, it is possible to write a character whether it is a pencil writing or a ballpoint pen writing. Alternatively, it is possible to obtain a good image in which the graphic image is not blurred or crushed. Therefore, by applying the image processing device according to the present invention to the character recognition device, it is possible to improve the character recognition accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a medium to be read.

FIG. 3 is a diagram showing a scanning direction of a medium to be read.

FIG. 4 is an explanatory diagram of a filtering process.

[Explanation of symbols]

 11 Scanning Section 12 First Image Storage Section 13 Writing Tool Discrimination Section 14 Second Image Storage Section 15 Filtering Switching Section 16 Pencil Filtering Section 17 Ballpoint Pen Filtering Section

Claims (1)

[Claims] 1. A writing instrument discriminating means for discriminating the type of a writing instrument used when writing a character or a figure from an image image read from a medium to be read, and an image corresponding to the writing instrument discriminated by the writing instrument discriminating means. An image shaping method selecting means for selecting a shaping method; and an image shaping means for performing an image shaping process on a read image of the medium to be read by the image shaping method selected by the image shaping method selecting means. A characteristic image processing device.