JPH04278678A - Image file device - Google Patents

Abstract

PURPOSE:To reduce and display both a halftone image and a non-halftone image with high picture quality by attaining the selection of at least two different reduction processing methods. CONSTITUTION:The compressed image information stored in an image memory 17 is transferred to an ODC 20 by a DMAC 16 and recorded on an optical disk 21. At the same time, a halftone flag is also recorded. A code decoding circuit 18 decodes the compressed information read out of the disk 21 into the raw image information. This raw image information is stored in the memory 17. Then it is decided whether the raw image information should be reduced or not for display it on a display 7 based on the original size information stored in a main storage 5. If the reduction processing is needed, the reduction rate is decided and at the same time a halftone flag stored in the storage 5 is checked. When the halftone flag is kept turned off, the reduction rate is reported to a reduction/magnification circuit 25 and also the OR reduction is designated. Meanwhile the thinning reduction is designated with the halftone flag kept turned on respectively.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image file device for storing and reproducing image information, and more particularly to an image file device having a function of reducing and displaying image information.

0002

2. Description of the Related Art Conventionally, in this type of image file device, when displaying an image on a display, if the size of the image is too large, the image is reduced at an appropriate reduction ratio and then output to the display. This reduction processing was performed by the so-called OR (logical sum) reduction method, in which sampling data is made black if there is even one black bit between sampling points on the image before reduction.

[0003] As an image reduction processing method, OR
In addition to the reduction method, there is a so-called thinning-reduction method in which bits of an image are thinned out at appropriate intervals. In addition, as a thinning and reduction processing method for halftone images (pseudo halftone images by dithering),
There is also a method in which thinning is performed in blocks of m×m bits (Japanese Unexamined Patent Publication No. 152162/1982).

0004

However, with the configuration of the conventional image file device described above, there is a problem in that when an image with halftones is reduced and displayed, the image quality deteriorates significantly.

However, the OR reduction method is applied without distinguishing between halftone images and non-halftone (binary) images. However, since the OR reduction method involves an increase in black bits, it is suitable for binary images such as characters, but images with halftones such as photographs (
In reality, this is because halftone information is likely to be lost if applied to a pseudo halftone image created by dithering or the like.

In order to solve these problems, it is conceivable to change the reduction processing method from the OR reduction method to the thinning reduction method. However, if the thinning/reduction method is applied to both halftone images and binary images, the image quality deterioration due to reduction of the halftone image will be improved, but on the contrary, it will be difficult to apply the thinning/reduction method to both halftone images and binary images. , it is not practical because the image quality deteriorates due to missing black bits, for example, characters become blurred.

The present invention has been made in view of the above-mentioned problems, and can be used for both images with halftones and images without halftones.
An object of the present invention is to provide an image file device capable of high-quality reduced display.

[0008]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an aid for distinguishing between encoded compressed image information and whether or not it involves halftones. The information is stored in the storage means, and the reduction means for reducing the decoded image information of the compressed image information read from the storage means is capable of selecting at least two different reduction processing methods. In addition, the apparatus is provided with means for selecting a reduction processing method of the reduction means in accordance with auxiliary information corresponding to the compressed image information read out from the storage means.

[0009]

[Operation] With the above-described configuration, the present invention allows the reduction means to select between the OR reduction processing method and the thinning reduction processing method,
According to the auxiliary information, select the thinning reduction processing method when displaying image information with halftones in a reduced size, and the OR reduction processing method when reducing image information without halftones, and select each image information. can be displayed in high quality.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an image file device according to an embodiment of the present invention. The overall configuration and operation of this image file device are outlined below.

[0011] The central processing unit (CPU) reads necessary programs stored in the hard disk (HD) 2 via the hard disk controller (HDC) 3.
It is loaded into the main storage device 5 via the system bus 4, and according to this program, controls each part of the device, controls data transfer,
Perform data processing. The CPU 1 interfaces with the device user through a display 7, a keyboard 8, and a mouse 9. That is, the CPU 1 stores data necessary for operation instructions from the user in the frame memory 10, and displays this data on the display 7 using the display/keyboard interface (CRTC) 11. The information entered by the user by operating the keyboard 8 or mouse 9 in response to this display is
11 to the CPU 12.

[0012] When an image import instruction is input, the CP
U1 instructs the scanner controller (SC) 13 to read the image, and causes the image scanner 14 to read the document. The image information (raw image information) of the read document is stored in the image memory 17 via the image bus 15 under the control of the SC 13. This raw image information is converted into compressed image information by the encoding/decoding circuit 18 and temporarily stored in the image memory 17. This compressed image information is transferred to an optical disc controller (ODC) 20 under the control of a direct memory controller (DMAC) 16, and recorded on an optical disc 21 under the control of this ODC 20. At this time, the CPU 1 creates data necessary for reproducing the compressed image information, transfers it to the ODC 20, and transfers it to the optical disc 20.
record it.

Note that when reading an image, the image memory 1
The raw image information stored in 7 or the raw image information reproduced from the optical disk 21 is sent to the printer controller (PC) 23 via the image bus 15 under the control of the DMAC 19.
By transferring the data to the printer 24, the data can be printed by the printer 24. Further, this raw image information can be displayed on the display 7. In this case, the raw image information in the image memory 17 is transferred to the image bus 1 under the control of the DMAC 19.
5 to the reduction/enlargement circuit 25 to reduce the image to a size that can be displayed on the display 7, and store this reduced image information in the image memory 17 as well as the frame memory 10.
Transfer to.

Note that data such as programs can also be written to or read from the floppy disk 27 by a floppy controller (FDC) 26.

Next, the details of the operation of this image file device will be explained below. First, a case will be described with reference to FIG. 2 in which the user selects the document reading/recording job from the menu displayed on the display 7 by the CPU 1 by operating the keyboard 8 or the mouse 9. In this case, the CPU 1 displays on the display 7 a selection screen for parameters for reading the original by the scanner 14, that is, original size, resolution, density, and halftone.
to be displayed. The user selects the document size, resolution, and density suitable for the document to be set on the scanner 14 on the screen by operating the keyboard 8 or mouse 9. Furthermore, if the document includes halftones such as photographs, the halftones are also selected as parameters (the halftone flag is turned on). CPU1 stores such selected parameters in SC1.
3 and instructs them to read the manuscript. The scanner 14 reads the original according to the notified parameters, and raw image information of the original is stored in the image memory 17 via the image bus 15.

The CPU 1 causes the DMAC 16 to transfer the raw image information in the image memory 17 to the encoding/decoding circuit 18 via the system bus 4, and transfers the compressed image information encoded by the encoding/decoding circuit 18 to the image bus 1 via the DMAC 19.
The data is temporarily stored in the image memory 17 via 5. next,
By transferring this compressed image information to the ODC 20 via the system bus 4 by the DMAC 16, the optical disc 2
The compressed image information area 30 of No. 1 is recorded. Also CPU1
receives from the ODC 20 a compressed image pointer indicating the recording position of this compressed image information on the optical disc. Then, this compressed image pointer, the parameters previously selected by the user, the header such as the document name input by the user,
Image information attribute data 40 consisting of other information is generated in the main storage device 5 and transferred to the ODC 20 to be recorded in the document management information area 31 on the optical disc,
Finish the series of processing.

In FIG. 2, 32 is a header, 33 is a header, and 33 is a header.
is the original size, 34 is the resolution, 35 is the density, and 36 is the halftone flag. The halftone flag 36 is
This is set to ON for originals with halftones, and OFF for originals without halftones. Further, 38 is a parameter specifying the compression method of the original image information, 39 is a compressed image pointer, and 37 is another parameter.

Next, a case will be described in which arbitrarily selected compressed image information on the optical disc 21 is reproduced and displayed on the display 7. FIG. 3 shows the flow of processing in this case. This selection of compressed image information is performed through interactive operations using the display 7 and keyboard 8 or mouse 9.

When this compressed image information is selected, the CP
U1 reads image information attribute data 40 regarding compressed image information selected from the document management information area 31 of the optical disc 21 into the main storage device 5 via the ODC 20 (step ST1). Then, using the compressed image information pointer 39 in this image information attribute data, the selected compressed image information recorded in the compressed image information area 30 of the optical disk 21 is read out via the ODC 20 and transferred to the system bus 4. via the image memory 17 (step ST2)
.

Next, the CPU 1 specifies parameters necessary for decoding the compressed image information, such as size, resolution, density, compression method, etc. in the image information attribute data read into the main storage device 5, to the encoding/decoding circuit 18, The DMAC 16 transfers the compressed image information stored in the image memory 17 to the encoding/decoding circuit via the system bus 4 to perform decoding processing into raw image information, and the DMAC 19 transfers the generated raw image information via the image bus 15. Store it in the image memory 17 (
Step ST3).

Next, the CPU 1 determines whether or not reduction processing is necessary in order to display the raw image information on the display 7, based on the document size information in the image information attribute data in the main storage device 5 ( Step ST4). If reduction processing is unnecessary, the CPU 1 causes the DMAC 16 to transfer the raw image information in the image memory 17 to the frame memory 10 via the system bus 4, and causes the CRTC 11 to display it on the display 7 (step ST5).

If reduction processing is necessary, the CPU 1 determines the reduction rate and checks the halftone flag in the main storage device 5 (step ST6).

When the halftone flag is off (non-halftone image), the reduction/enlargement circuit 25 is notified of the reduction rate, OR reduction is specified as the reduction processing method, and the DMAC 19 saves the raw image information in the image memory 17. image bus 1
5 to the reduction/enlargement circuit 25 to execute OR reduction processing, and the DMAC 16 stores the generated reduced image information in the image memory 17 via the system bus 4 (step ST7). Next, the CPU 1 causes the DMAC 16 to transfer the reduced image information in the image memory 17 to the frame memory 10 via the system bus 4, and causes it to be displayed on the display 7 (step ST9).

On the other hand, when the halftone flag is on, the raw image information in the image memory is image information with halftones (pseudo halftone image information by dithering method, etc.), so the CPU 1
The thinning/reducing method is selected as the reduction processing method, this is specified together with the reduction rate to the reduction/enlargement circuit 25, and the DMAC 19 transfers the raw image information in the image memory 17 to the image bus 1.
5 to the reduction/enlargement circuit 25 to execute thinning/reduction processing, and the obtained reduced image information is stored in the image memory 17 via the system bus by the DMAC 16 (step ST8). Next, the CPU 1 causes the DMAC 16 to transfer the reduced image information in the image memory 17 to the frame memory 10 and display it on the display 7 (step ST9).

Here, the thinning/reducing process selected in the case of halftone image information is a method in which only the bits of the reduced image are directly sampled from the raw image information, and the remaining bits in the raw image information are discarded. . In Figure 4, (c) and (d
) The image information 52 and 53 shown in (a) are the raw image information 5 shown in (a).
This is an example of image information in which 0 is reduced to one-third by thinning/reduction processing. However, the reduced image information 52 shown in (c) is reduced from the coordinates (1, A) on the raw image information 50, and the reduced image information 53 shown in (d) is the one that is This is a reduction from (2, B) as the starting point.

On the other hand, the OR selected when the tone is not halftone
Reduction processing is a method in which, when sampling the number of bits of a reduced image, if even one black bit exists between sampling points on the raw image information, the sampling data is made into a black bit. When the raw image information 50 shown in (a) of FIG. 44 is reduced to one-third by OR reduction processing, (b)
) is obtained.

As is clear from comparing the OR reduced image information 51 and the thinned out reduced image information 52 and 53 in FIG. 3, black dots do not increase in thinned out reduction as in OR reduction.
High-quality reduced display of halftone image information is possible.

Note that in the case where the raw image information of the original read by the scanner 14 is directly reduced and displayed on the display 7, if the user specifies a halftone, the raw image information is reduced by thinning/reducing processing. If no halftone is specified, OR the reduction of the raw image information.
This can be done by reduction processing.

It is also possible to apply an appropriate reduction processing method other than the OR reduction method to non-halftone image information, and to apply an appropriate reduction processing method other than the thinning reduction method to halftone image information.

[0030]

Effects of the Invention As is clear from the above description, the present invention stores compressed image information from the storage means as well as auxiliary information (halftone flag) for distinguishing whether or not it involves halftones. is read out and the method for reducing the decoded image information of the compressed image information is selected according to this auxiliary information. Therefore, for example, image information with and without halftones can be displayed in a reduced size with high image quality. This has the effect of

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an image file device according to an embodiment of the present invention.

[Figure 2] Explanatory diagram of recording area and image information attribute data on an optical disc

[Fig. 3] Flowchart showing an outline of processing during playback/display of recorded image information

FIG. 4 is an explanatory diagram of image information showing a comparison between pre-reduction image information and reduced image information obtained by an OR reduction method or a thinning reduction method.

[Explanation of symbols]

1 Central processing unit (CPU) 2
Hard disk (HD) 3 Hard disk controller (HDC) 4 System bus 5 Main storage device 7 Display 10 Frame memory 11 Display/keyboard interface (CRTC) 13 Scanner controller (SC) 14
Scanner 15 Image bus 16 Direct memory access controller (
DMAC) 17 Image memory 18 Encoding/decoding circuit 19 Direct memory access controller (
DMAC) 20 Optical disk controller (ODC) 21
Optical disc 25 reduction/enlargement circuit

Claims (1)

[Claims] Claims: 1. Storage means for storing encoded compressed image information in association with auxiliary information for distinguishing whether or not it involves halftone; a decoding means for decoding the compressed image information obtained by the decoding means, a reduction means for reducing the decoded image information by the decoding means by one of at least two different reduction processing methods, and displaying the reduced image information by the reduction means. An image file device comprising: a display means; and means for selecting a reduction processing method of the reduction means according to auxiliary information corresponding to compressed image information read from the storage means.