JPH0622149A - Picture input device - Google Patents

Abstract

PURPOSE:To efficiently compress a stored occupancy quantity by converting a picture of an original into picture mode information, thereafter storing the picture, selecting a specific picture mode compression means optimum to the picture mode and applying compression processing to the storage content of the picture mode. CONSTITUTION:When the user scans a scanner onto a prescribed original while depressing a read switch of a handy scanner operation section 14, picture data on the original are fetched via a CCD image sensor and the scanner fetches the picture continuously till the user opens the read switch. A picture mode is placed at the head of the fetched picture data and specific information required for a compression processing item corresponding to this is written in a picture memory 13, and after the end of scanning is confirmed, the compression switch is depressed. Thus, a control section 15 reads the picture mode at the head of the picture file written in a picture memory 13 and selects an optimum compression processing items in response to the type of the mode. After the selection, a picture compression section 17 executes the compression processing of the specific processing item.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device used for a handy scanner, for example, and more specifically, it can efficiently compress the memory occupation amount of image data to enhance the effectiveness of the memory section. The present invention relates to an image input device.

[0002]

2. Description of the Related Art In recent years, an image input device used for a handy scanner or the like reads a chart, a sentence, a halftone image, etc. of a document and inputs the image. In this case, the storage unit for inputting an image consumes a large amount of storage capacity, so that the storage capacity is saved. For example, the storage occupancy of read image data is compressed by capturing the statistical properties of line drawings and text originals such as the MR encoding system and the MH encoding system of facsimiles.

However, not only the shade of white and black,
In the case of image data having a halftone (gray) or multi-tone data having a large number of gray levels having 256 tones per pixel, the statistical properties are different, so that the image data cannot be sufficiently compressed. Had.

[0004]

Therefore, according to the present invention, for each type of image data read from a document, an optimum compression means corresponding to the type is specified, and a sufficient compression process is performed based on the specified compression means. It is an object of the present invention to provide an image input device capable of performing.

[0005]

SUMMARY OF THE INVENTION The present invention is an image input device for inputting image data obtained by reading an image of a document through image reading means, wherein the image data read by the image reading means is processed in an image mode. Image processing means for performing conversion processing on the image processing means, storage means for storing the image mode converted by the image processing means, and storage contents of the image modes stored by the storage means for optimum compression according to the type of the mode. Various image mode compression means for performing compression processing by the processing means, selection means for selecting a specific image mode compression means corresponding to the stored image mode from the various image mode compression means, and specification selected by the selection means The image mode compression means is provided with a control means for compressing the stored contents of the image mode stored in the storage means.

[0006]

According to the present invention, when the image reading means reads the image of the original, the read image data is converted into the image mode by the image processing means and then stored in the storage means. The selecting means selects a specific image mode compression means that is most suitable for the stored image mode, and the selected optimum image mode compression means compresses the stored contents of the image mode.

[0007]

As described above, since the optimum compression processing means according to the type of the image mode can be associated and compressed, the image mode stored in the storage means has image data having halftones having different statistical properties or Even with multi-gradation data, always perform optimal compression processing according to various image data,
The storage occupancy of image data can be compressed most efficiently.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The drawing shows an example in which the image input device is applied to a handy scanner, and FIG. 1 is a control circuit block diagram of the handy scanner.
The image processing unit 12, the image memory 13, the handy scanner operation unit 14, the control unit 15, the communication control unit 16, and the image compression unit 17 are included.

The above-mentioned reading unit 11 uses a CCD image sensor, and scans the document with a scanning unit of a handy scanner to read the image data of the document scanned by the CCD image sensor. The read image data is guided to the image processing unit 12, where it is converted into an image mode such as binarization, dithering representing halftone, and error diffusion. The converted image mode is stored in the image memory 13.

The handy scanner operation unit 14 has a reading switch and a compression switch at the grip portion of the handy scanner held by the user, and the user operates the reading switch to scan the handy scanner in a predetermined direction on the document. By doing so, the LED interlocking with this is turned on to perform the reading operation, and the reading switch is opened to set L
The ED is turned off to stop the reading operation. After the reading operation is completed, the compression switch is operated to execute the compression processing on the read image data.

The control unit 15 controls each circuit device according to a preset program, and the communication control unit 16 transfers the data-processed control data to the host computer on the apparatus main body side, and the image compression unit 17 Has several types of compression processing items such as binary compression, dither compression, error diffusion compression, multi-gradation compression, and performs predetermined compression processing based on the compression processing items specified by the control unit 15.

In this case, when selecting the compression processing item,
The control unit 15 selects an optimum compression processing item corresponding to each type of image mode from several kinds of compression processing items. This is because when the read image data is processed as a single file, the image mode at the beginning thereof and specific information required for the compression processing item corresponding to the image mode, for example, the number of data per line, The number of lines in the scanning direction and the like are written, and the control unit 15 reads the first image mode of this image file to select the optimum compression processing item according to the type of image mode. As a result, the read image data is compressed most efficiently, the compression process is not wasted, and the occupied amount of the image memory 13 is surely reduced.

An image processing operation for inputting an image on a document using the handy scanner thus constructed will be described with reference to the flowchart of FIG. Now, when the user scans the predetermined document with the handy scanner while pressing the reading switch of the handy scanner operation unit 14, the image data on the document is taken in through the CCD image sensor and read by the user. The loading operation is continued until the switch is opened (steps n1 to n3).

In the captured image data, the image mode and the specific information required for the compression processing item corresponding to the image mode are written in the head portion thereof, and when scanning is completed, one image file is created. It is written in the image memory 13. Then, after confirming the completion of scanning, when the user presses the compression switch, the control unit 15 reads the first image mode of the image file written in the image memory 13, and according to the type of the read image mode. The optimum compression processing item is selected (step n4).

After the selection, the image compression unit 17 causes the control unit 15 to execute the compression process of the specific compression process item.
For example, when the control unit 15 determines that the binary compression is optimal based on the statistical property of the image mode, this binary image has a property that white and black columns continue for a long time. Therefore, when white data is detected, This length is counted, and the original data is replaced with one piece of white data and the length value to perform compression processing (steps n5 to n8).

As described above, since the optimum image compression section corresponding to each type of image mode can be associated and compressed, the image mode stored in the image memory has a large number of image data having halftones having different statistical properties or a large number of image data. Even with gradation data, the optimum compression processing is always executed according to various image data,
The storage occupancy of image data can be compressed most efficiently.

In the correspondence between the present invention and the configuration of the above-described one embodiment, the image input device of the present invention corresponds to the handy scanner of the embodiment, and hereinafter, similarly, the image reading means uses a CCD image sensor. The image processing unit corresponds to the image processing unit 12, the storage unit corresponds to the image memory 13, the image mode compression unit corresponds to the image compression unit 17, the selection unit and the control unit. Although the means corresponds to the control unit 15, the present invention is not limited to the configuration of the above-described embodiment. For example, the control unit 15 directly obtains statistical data without applying the image mode to the beginning of the image file or compressing the image at the same time as capturing the image, and selects the optimum compression processing item based on the obtained value. You can also

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit of a handy scanner according to the present invention.

FIG. 2 is a flowchart showing an image processing operation of the handy scanner of the present invention.

[Explanation of symbols]

 11 ... Reading unit 12 ... Image processing unit 13 ... Image memory 15 ... Control unit 17 ... Image compression unit

Claims (1)

[Claims] 1. An image input device for input-processing image data obtained by reading an image of an original through image reading means, comprising image processing means for converting the image data read by the image reading means into an image mode. Storage means for storing the image mode converted by the image processing means, and various types of compression processing of the stored contents of the image mode stored by the storage means by the optimum compression processing means according to the type of the mode. The image mode compression means, the selection means for selecting a specific image mode compression means corresponding to the stored image mode from the various image mode compression means, and the specific image mode compression means selected by the selection means, An image input device, comprising: a control unit for compressing the storage contents of the image mode stored in the storage unit.