JP2003169209A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus that can automatically designate an image processing mode before copying an original and can automatically designates the image processing mode to each original even when an automatic draft feeder automatically feeds a plurality of originals. <P>SOLUTION: The operating flowchart of the image processing apparatus includes: a step of conducting main scanning to apply image processing to an acquired image in a designated image processing mode when an instruction to start the image processing is received in the case that the image processing mode is designated; and a step of executing preliminary scanning to decide the image processing mode based on the acquired image from the preliminary scanning when an instruction to start the image processing is received in the case that no image processing mode is designated, executing main scanning and applying image processing to the image acquired image by the main scanning in the decided image processing mode. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an image processing apparatus capable of performing image processing on acquired image data in any one of a character mode, a photograph mode, a halftone dot mode, and a character / photograph / halftone dot mixed mode. .

[0002]

2. Description of the Related Art Conventionally, an image processing apparatus has a function (also called an image quality mode) of selecting an image processing mode for selecting an image processing method according to a document. As the image processing modes that can be selected, there are a character mode, a photo mode, a halftone dot mode, and a mixed mode. When the user designates a target image processing mode, image processing is performed in the designated mode.

That is, in the character mode, image processing for increasing the contrast is performed on the acquired image.
Further, in the photograph mode, image processing is performed on the acquired image so as to more faithfully reproduce the original. In the halftone dot mode, the acquired image is subjected to descreening processing to suppress moire. In the mixed mode, areas of characters, photographs, and halftone dots are determined, and the above-described suitable processing is performed for each area.

[0004]

By the way, in the prior art,
In order to make a copy using these modes, the user needs to look at the original image, determine in advance which image processing mode is suitable for the image, and specify the mode. Therefore, it is very troublesome and difficult to specify the mode.

Further, in the case where an automatic document feeder is mounted and a plurality of documents are automatically fed to make a copy, an image processing mode is designated for each continuously fed document. In some cases, a copied image with deteriorated image quality may be obtained.

The present invention has been made in consideration of the above circumstances, and even when an image processing mode can be automatically designated before copying an original, and even when an automatic paper feeder automatically feeds a plurality of originals. An object of the present invention is to provide an image processing apparatus capable of automatically specifying an image processing mode for each original.

[0007]

In order to achieve the above object, in the image processing apparatus according to claim 1 of the present invention, when an image processing start instruction is issued when an image processing mode is designated, Perform a main scan and perform image processing on the acquired image in the specified image processing mode.If there is an instruction to start image processing when the image processing mode is not specified, prescan. The image processing mode is determined based on the image thus acquired, the main scan is performed, and the image acquired thereby is subjected to image processing in the determined image processing mode.

An image processing apparatus according to a second aspect is characterized in that the image processing mode includes a character mode, a photograph mode, a halftone dot mode, and a character / photograph / halftone dot mixed mode.

In the image processing apparatus according to the third aspect, an image area separation determination process is performed for each pixel of the image acquired by prescanning, and character data and photographic data are determined based on the determination result. , The halftone dot data is determined, and the image processing mode is determined based on the determination result of all pixels.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an image processing apparatus according to an embodiment of the present invention.

Here, the configuration of the facsimile apparatus F is shown as the image processing apparatus, but the present invention is not limited to this example, and any apparatus that has a scanner connected and has an image processing function may be used. It may be a personal computer to which a machine or a scanner is connected.

The facsimile apparatus F includes a control section 1 for controlling the facsimile apparatus F, an original scanning section 2 for reading a set original and performing image processing in any one of a plurality of image processing modes described later. , An operation input unit 4 including various operation keys, a codec 5 for encoding and decoding image data, an image memory 6 for storing image data, and a display unit 7 including a liquid crystal screen or the like.
A modem 8 for modulating and demodulating various signals required for facsimile communication, a network control unit (NCU) 9 for controlling connection to a telephone line, and a printer 10 for printing out image data.

The control unit 1 is provided with a CPU 10, a ROM 11 storing various programs necessary for the facsimile apparatus F to operate, a RAM 12 storing speed dials and the like, and a timer 13 for clocking the time.

The document scanning unit 2 includes a scanning carriage 22, a motor 21 for driving the scanning carriage 22, a light source 23,
A home position sensor 24 that detects the initial position of the scanning carriage 22 and a document size detection sensor 25 that detects the document size are provided. Further, based on the detection results of the home position sensor 24 and the document size detection sensor 25, the motor 21,
The mechanism control unit 20 that controls the light source 23 is provided.

The document scanning section 2 also includes an image sensor 28 including a CCD, a scanning image memory 29, a parameter memory 30, and an image processing means 26 having a mode selecting means 27.

The operation input section 4 includes a start button 40,
A mode designation button 41 is provided. Here, the mode designation button 41 is means for setting the image processing mode to any one of the automatic selection mode, the character mode, the halftone dot mode, and the mixed mode by its operation. The functions of the components of the document scanning unit 2 and the operation input unit 4 will be described later.

According to this structure, the following processing can be performed when reading the original. That is,
As shown in FIG. 2, the original is set on the original scanning unit 2 and
When the start button 40 is operated (a1), it is determined whether the automatic selection mode is selected as the image processing mode (a2).

As a result, if the mode is the automatic selection mode, the process shifts to the process A (see FIG. 3) which will be described later. If any one of the halftone dot mode and the mixed mode is designated, the light source 23 is turned on, the scanning carriage 22 is started to operate, and the document 1
Reading of the original image per sheet is started (a3).

Then, the original is scanned to acquire its image data (a4), the acquired image data is processed with the parameters of the designated image processing mode, and the scanned image memory 2 is processed.
9 (a5).

Then, the image data stored in the scanning image memory 29 is read out and recorded by the printer 10 (a6).

When the reading of all the originals is completed (a7) by repeating the processes of steps a4 to a6 described above (a7), the light source 23 is turned off and the scanning carriage 22 is returned to the home position (a8). .

Next, the above-mentioned process A will be described with reference to FIG. That is, in the process shown in step a2 of FIG. 2, if the automatic selection mode is designated as the image processing mode, the light source 23 is turned on, the scanning carriage 22 is started, and the reading of the original image is started (b1). ).

Then, the document is scanned by a predetermined number of lines to obtain its image data (b2), and the data necessary for determining the image processing mode is created from the image data of the scanned lines (b3). . Note that the data necessary for determining the image processing mode is the read image data itself, and the image processing mode is determined in the image processing means 26 by analyzing the image data to be described later. Determine processing parameters.

Such processing is called prescan in the present invention, and when the reading of all originals is completed (b4), the image processing means 26 analyzes the data obtained in step b3 to set the image processing mode. Then, the image processing parameter is determined (b5). Then, the light source 23 is turned off,
The scanning carriage 22 is returned to the home position (b6).

If the scanning carriage 22 has reached the home position (b7), the light source 23 is turned on to start the operation of the scanning carriage 22 to start reading the original image per original (b8). ).

Then, the original is scanned to acquire its image data (b9), the acquired image data is processed by the parameters of the image processing mode determined by the prescan processing described above, and the scanned image memory 29 is processed. To store (b1
0).

Then, the image data stored in the scanning image memory 29 is read out and recorded by the printer 10 (b11).

When the processing of the above steps b9 to b11 (main scan) is repeated and reading of all originals is completed (b12), the light source 23 is turned off and the scanning carriage 22
To the home position (b13).

Next, the automatic mode selection process described above will be described with reference to FIGS. That is, as shown in the conceptual diagram of FIG. 5, for each pixel of the image data read by the prescan, the image processing means 26 determines whether it is character data, photographic data or halftone dot data (c0). Then, the number of pixels determined for each data type is added up, and the ratio to the total number of pixels is calculated (c2).

In this way, when the determination results of all pixels are accumulated for each data type and the ratio is calculated, a histogram as shown in FIG. 6 is created, and the ratio for each data type and a predetermined threshold value are set. The image processing mode is determined by comparing and.

That is, if the ratio of the halftone dot data exceeds a predetermined threshold value (50% of the total number of pixels in this case) of the halftone dot data (c3), the image processing mode is set to the halftone dot mode (c4). ).

If the ratio of the character data exceeds a predetermined threshold value of the character data (here, 50% of the total number of pixels), the image processing mode is set to the halftone dot mode (c
6). Further, if the proportion of the photographic data exceeds a predetermined threshold value (50% of the total number of pixels in this case) of the photographic data (c7), the image processing mode is set to the photographic mode (c8).

If none of the character data ratio, photographic data ratio, and halftone dot data ratio exceeds the threshold value, the image processing mode is set to the mixed mode (c9).

In the example shown in FIG. 6, the threshold value for halftone dot data, the threshold value for character data, and the threshold value for photographic data are the same, but FIG. 7 shows another embodiment. As shown, the threshold value may be different for each data type.

For example, the threshold of character data is 80%,
The threshold of photographic data may be 40% and the threshold of halftone dot data may be 50%. In any of the examples, if the ratio of two or more data types exceeds the threshold set for each data, and if the ratio of all data types does not exceed the threshold set for each data, The mixed mode is selected as the image processing mode.

Similarly, if the ratio of only one data type exceeds the threshold value set for each data type, that mode is selected as the image processing mode. In addition,
The resolution conversion process may be performed to reduce the number of pixels for which the data type should be determined, instead of all the pixels read by the pre-scan.

[0037]

As described above, according to the first aspect of the present invention.
In the image processing apparatus described in (1), when the image processing start is instructed when the image processing mode is not designated, the pre-scan is performed, the image processing mode is determined based on the image acquired by this, and the main scan is performed. Image processing is performed on the acquired image in the decided image processing mode, so the image processing mode can be automatically specified before copying the original, and the automatic paper feeder automatically feeds multiple originals. Even in this case, the image processing mode can be automatically designated for each document.

In the image processing apparatus according to the second aspect, the image processing modes include a character mode, a photograph mode, a halftone dot mode, and a character / photograph / halftone dot mixed mode.
In the image processing apparatus according to the first aspect, any one of these modes can be automatically selected.

In the image processing apparatus according to the third aspect, the image area separation determination processing is performed for each pixel of the image acquired by the prescan, and based on the determination result, character data and photographic data are obtained. , The image processing mode is determined based on the determination result of all the pixels, which is the halftone dot data, so that the appropriate image processing can be easily and quickly performed based on the image data acquired by the prescan. The mode can be determined.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a main configuration of an image processing apparatus of the present invention.

FIG. 2 is a flowchart for explaining the operation of the image processing apparatus.

FIG. 3 is a flowchart for explaining the operation of the image processing apparatus.

FIG. 4 is a flowchart for explaining the operation of the image processing apparatus.

FIG. 5 is a diagram for explaining an automatic selection process of an image processing mode.

FIG. 6 is a diagram showing an example of a histogram.

FIG. 7 is a diagram showing another example of a histogram.

[Explanation of symbols]

F: Facsimile device (image processing device)

Claims (3)

[Claims] 1. When an image processing start is instructed when the image processing mode is designated, a main scan is performed and image processing is performed on the acquired image in the designated image processing mode, while the image processing is performed. When the image processing start is instructed when the processing mode is not specified, the pre-scan is performed to determine the image processing mode based on the image acquired by this, the main scan is performed, and the acquired image is On the other hand, an image processing device that performs image processing in the determined image processing mode. 2. The image processing apparatus according to claim 1, wherein the image processing modes include a character mode, a photo mode, a halftone dot mode, and a character / photograph / halftone dot mixed mode. 3. The image data obtained by the prescan according to claim 1 or 2, wherein image area separation determination processing is performed for each pixel of the image, and character data and a photograph are obtained based on the determination result. An image processing apparatus, characterized in that it is determined whether it is data or halftone dot data, and the image processing mode is determined based on the determination result of all pixels.