JP3252987B2 - Image processing device - Google Patents

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 performing compression / expansion processing, and more particularly to an image processing apparatus for performing compression / expansion processing on image signals supplied from various external devices.

[0002]

2. Description of the Related Art For example, when a video signal obtained from a video camera or an image signal electronically generated by a computer is subjected to image processing such as editing, and then printed on paper, these are used. Is temporarily stored in a memory, and various image processes are often performed on the image signal in the memory. When storing an image signal in a memory, the amount of data is too large for a raw image signal. Therefore, the image signal is generally compressed and stored in the memory. For example,
Japanese Patent Laying-Open No. 4-10764 discloses an apparatus for performing a compression process on an image signal sent from an external device.

[0003]

However, in a conventional image processing apparatus, a compression process is performed irrespective of the resolution, size, and the like of an image sent from an external device. There is a problem that deterioration occurs. In particular, when an irreversible compression method such as discrete cosine transform is applied to a character image, the original image is not completely reproduced when decompressed, so that there is a problem that a fine line cannot be faithfully reproduced. Further, in the conventional image processing apparatus, the image signal once stored is only output to an image forming apparatus such as a printer. However, there are many restrictions due to the type, data amount, required image quality, and the like.

Accordingly, the present invention provides an image processing apparatus capable of performing optimal image processing in accordance with the type of input information and making the processed image information available to other external devices. With the goal.

[0005]

According to the present invention, there is provided an image processing apparatus comprising: a plurality of image processing units for inputting image signals;
Input means, and compressing means for compressing the input images signal, storage means for storing the image signal compressed by the input image signal or the compression means, decompression for decompressing compressed image signals Means for outputting image signals
Output means, and screens according to the input selection information and the output selection information.
Input means for inputting an image signal and output means for outputting an image signal
Select the stage and type of input image data and image signal
Of the input image in combination with the device that outputs
When the image signal is stored in the storage unit, the image signal is compressed by the compression unit.
Control whether to reduce the size and read from the storage means.
When outputting the extracted image signal to the output means,
Control means for controlling whether or not to extend by long means
And it said that there were pictures.

[0006]

The operation of the present invention will be described with reference to FIG.

FIG. 1 is a block diagram for explaining the operation of the image processing apparatus according to the present invention. The image processing apparatus includes: an image input selecting unit 1 for selecting an external device from which an image signal is input; a compression unit 2 for compressing the input image;
A compression bypass unit 3 for passing an input image without compression, a memory unit 4 for temporarily storing a compressed image or an original image that is not compressed, and an expansion unit for expanding a compressed image signal stored in the memory unit 4. Unit 5, an expansion bypass unit 6 that allows the compressed image signal or the uncompressed image signal stored in the memory unit 4 to pass through as it is, and selectively transmits the image signal from the expansion unit 5 or the expansion bypass unit 6 to a desired external device. And a control unit 8 that receives an external command to control the operation of the entire apparatus.

The image input selection means 1 is supplied with image signals from different external devices as inputs A, B, and C, respectively. The image input selection means 1 selects a target image signal based on an instruction from the control unit 8. When the capacity of the input image signal is large, it is compressed by the compression unit 2 and then stored in the memory unit 4. When the capacity of the input image signal is small, or when the image quality is deteriorated by performing the compression process, the input image signal is supplied to the compression bypass unit 3 and the compression process is not performed. Memory part 4
To accumulate.

At the time of outputting an image signal, the image signal stored in the memory unit 4 is read out. If the image signal is a compressed image signal, the image signal is restored by the decompression unit 5 to the original image signal.
Alternatively, the image data is supplied to the image output selection unit 7 through the decompression bypass unit 6 while being compressed as necessary. If the signal is an uncompressed image signal, it is supplied to the image output selection unit 7 through the decompression bypass unit 6.

The image output selection unit 7 supplies outputs D, E, and F to predetermined external devices according to the purpose.

In FIG. 1, the compression bypass unit 3
The extension bypass section 6 is shown as an independent block in order to clarify the operation of the present invention. However, in an actual circuit, the extension bypass section 6 exists as an independent block as can be understood from the embodiment described below. Absent.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments with reference to the drawings.

FIG. 2 is a block diagram of an image processing system including the image processing apparatus of the present invention. The image processing device 21 includes a computer 22 and a video device 2 as external devices.
3. Printer 24, communication circuit 2 for communicating with remote locations
5 etc. are connected.

In the computer 22, an image signal of a color image is electronically generated, and the image signal is generated by a SCSI (Small Co.).
The image data is input to the image processing apparatus 21 via a general-purpose input / output circuit such as an input system interface (MPU). The images input to the image processing device 21 include various types such as photographs, computer images, figures, and characters.

The video equipment 23 includes, for example, an electronic still camera, a high-definition television, and the like. The video device 23 temporarily stores an image signal obtained by capturing an image of a subject and outputs the image signal as a digital signal, or outputs the image signal as an analog signal together with a synchronization signal to perform image processing. The data may be converted into digital data by the device 21.

The printer 24 is, for example, a color printer that forms a color image by transferring a plurality of color toner images onto a sheet of paper by electrophotography. As a color printer, toner images of different colors are sequentially formed one by one on one photosensitive drum, and are transferred in a superimposed manner for each color onto a sheet wound around a transfer drum provided in contact with the photosensitive drum. A system of a type or a system in which a plurality of photosensitive drums are arranged along a paper transport path and toner images of different colors are sequentially transferred onto paper by each of the photosensitive drums is used. In any case, an image signal subjected to image processing is transmitted from the image processing device 21 to the printer 24 in synchronization with the process, modulates a laser beam for exposing the photoconductor, and forms an electrostatic latent image on the photoconductor. A toner image is obtained by developing the electrostatic latent image.

FIG. 3 is a block diagram showing a configuration example of the image processing apparatus 21. In FIG. 3, reference numeral 31 denotes a video device 2
A video signal input circuit to which a video signal from 3 is supplied;
32 is a general-purpose input / output circuit for exchanging data with the computer 22 or the like, 33 is a communication input / output circuit for exchanging data with a remote external device via the communication circuit 25, and 34 is CP for controlling the operation of the entire image processing apparatus
A U circuit, 35 is a compression circuit for compressing an input image signal based on a predetermined compression method, 36 is a memory circuit for storing image signals, and 37 is a compression circuit for compressing a compressed image by the compression circuit 35. A decompression circuit 37 for decompressing in a corresponding decompression method. The CPU circuit 34 selects input and output, compresses and compresses the data according to the content of a control command given from the outside.
The user selects whether or not to perform decompression processing, and selects a compression / decompression method.

Hereinafter, the operation of the image processing apparatus of the present embodiment will be described with reference to the flowchart of FIG.

An external device, for example, a user interface connected via a bus, or a host computer connected via a communication line, etc.
When the command of the control content reaches the U circuit 24 (step 10
1), the CPU circuit 24 selects an image input based on the control contents (step 102). The command of the control content includes all information of input selection, presence / absence of compression / decompression, and output selection. In the example shown in FIG. 3, one of the video signal input circuit 31, the general-purpose input / output circuit 32, and the communication input / output circuit 33 is selected, and the selected circuit is set in an operable state.

Next, a compression method is selected (step 10).
3). When the input image is a full-color raster image, for example, JPEG (Joint P
photographic Experts Grou
p) method, character information and full-color raster images, JPEG method and JBIG (Joint Bi-le)
In the case where the purpose is to output data to the printer 24 at high speed, a fixed-length compression algorithm is selected. In addition, many raster images created by a computer have a size of about 1000 × 1200 pixels, and the amount of data per sheet is small. In some cases, an image compressed in advance by the computer is sent. Therefore, in general, the full color image size is the full resolution of the printer, for example, 400 spi (sp
Some of them are sufficiently smaller than 8 bits for each color and do not need to be compressed. In that case, select no compression. Also, for images for which degradation of image quality is expected to occur due to compression processing, no compression is selected. The compression circuit 35 compresses the image signal based on the selected method. The image signal compressed by the compression circuit 35 is stored in the memory circuit 36. When the compression process is not performed, the input image signal is not supplied to the compression circuit 35, but is directly input to the memory circuit 36 as an uncompressed image signal.
Is stored in

Next, in the expansion circuit 37, the compression circuit 3
A decompression method corresponding to the compression method adopted in step 5 is selected (step 104). However, if the output destination of the image signal requires a compressed image signal, the decompression circuit 37
Is selected for the mode without decompression.

Next, the CPU circuit 34 selects an output destination of the image signal based on the control contents (step 105). As a result, the image signal is input to the computer 22, output to the printer at a remote location via the communication circuit 25, or output to the printer 24 at hand. The image information output from the image processing device 21 may be a non-compressed image signal or a compressed image signal.

When the above processing is completed, the CPU circuit 24
Outputs a ready signal indicating that the next command can be received to the outside (step 106).

Note that the external devices connected to the image processing apparatus 21 are not limited to those shown in FIG.
It is possible to connect an image scanner that reads an image of a document with the D sensor, and it is also possible to connect a thermal sublimation printer or the like as an external device for image output.

[0025]

As described above, according to the present invention,
The connection relationship with a plurality of external devices can be selected, and the compression / decompression processing can be switched according to the nature of the image information from the external device or the image information to be supplied to the external device. Optimal processing can be performed according to the external device connected to the device.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining the operation of an image processing apparatus according to the present invention.

FIG. 2 is a block diagram of an image processing system including the image processing apparatus of the present invention.

FIG. 3 is a block diagram illustrating a configuration example of an image processing apparatus.

FIG. 4 is a flowchart illustrating an operation of the image processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image input selection part, 2 ... Compression part, 3 ... Compression bypass part, 4 ... Memory part, 5 ... Decompression part, 6 ... Decompression bypass part,
7 image output selection unit, 8 control unit, 21 image processing circuit, 22 computer, 23 video equipment, 24 printer, 25 communication circuit, 31 video signal input circuit
32 ... General-purpose input / output circuit, 33 ... Communication input / output circuit, 34
... CPU circuit, 35 ... Compression circuit, 36 ... Memory circuit, 3
7 ... Expansion circuit

Claims (2)

(57) [Claims] A plurality of input means for inputting an image signal;
When the compression means for compressing the input images signal, storage means for storing the image signal compressed by the input image signal or the compression means, the expansion means for expanding the compressed image signal, A plurality of output means for outputting an image signal, and an image signal input according to input selection information and output selection information
Input means to output and output means to output image signal
The type of the input image data and the image signal are output.
The input image signal before
Whether or not to be compressed by the compression means when storing in the storage means
And read the image read from the storage means.
When outputting an image signal to the output means,
An image processing apparatus comprising: a control unit that controls whether or not to perform expansion . 2. An image signal input based on input selection information.
Selecting means, a compressing means for compressing the input image signal, and an input image signal or compressed by the compressing means.
Storage means for storing the compressed image signal, and a compressed image signal
Expansion means for expanding the image signal, and means for selecting the output destination of the image signal based on the output selection information.
And the type of input image data and the output destination of the image signal.
The input image signal or the input image signal
When the image signal compressed by the stage is stored in the storage means,
In both cases, the image signal read from the storage means or
The image signal read from the storage means is read by the decompression means.
Control means for outputting an expanded image signal.
Characteristic image processing device.