JPH0937075A - Device and method for processing image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly process and transmit large amount of multilevel data by pseudo-halftone-processing a picture signal through the use of a picture circuit (hardware) in the main body of a copying machine. SOLUTION: Reading picture is instructed in a picture reading part 100 to successively takes the binary signals of Yellow (Y), Magenta (M), Cyanogen (C) and Black (B) generated by an internal hardware circuit to RAM 52 in a host computer 200 through a video interface 150 by each picture element. The obtained binary signals Y, M, C and K are converted corresponding to the resolution and the number of gradation of CRT 201. Algorithm of pseudo halftone processing executed by a pseudo halftone processing circuit 47 at this time and the size and the resolution of the object picture are reported to the host computer 200 via a control line. Then they are preview-displayed on CRT 201 and at this time a result processed by hardware in the picture reading part 100 is transferred to enable quick preview display.

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 having a function of processing an image formed by an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, by utilizing the functions of the scanner section and printer section of a digital copying machine, a document is read,
A technique is known in which an image signal is taken out to a computer or a graphic image made on the computer is printed.

[0003]

At this time, the image signal is
Since it is a multi-valued signal such as 8 bits per pixel, it takes a long time to transmit the original when reading the original with a scanner and outputting it to the CRT monitor on the personal computer because the data amount is large especially in the case of full color image signal. Was there. Moreover, in order to preview the state of the binarization process on the copying machine side, for example, it is necessary to perform the binarization process by the software process on the host computer, which takes a lot of time.

Therefore, the present invention provides an image processing apparatus capable of high-speed transmission and high-speed processing at the time of processing by a host computer by utilizing hardware such as a binarization processing circuit provided in the main body of the image forming apparatus. The purpose is to

[0005]

In order to solve the above-mentioned problems, an image processing apparatus according to claim 1 of the present application comprises a processing means for performing pseudo-halftone processing on an input image signal, and the processing means. It is characterized by further comprising image forming means for forming an image by using the outputted pseudo halftone signal as a recording signal, and output means for outputting the pseudo halftone signal to an external device.

The image processing apparatus according to claim 5 is
An image processing apparatus for processing an input image signal to create an image signal for recording and previewing an image formed by an image forming apparatus for forming an image on a medium by a recording unit, the recording apparatus comprising: The image forming apparatus further comprises interface means for extracting the image signal for recording from the image forming apparatus, and the interface means extracts the image signal for recording obtained by performing pseudo halftone processing in the image forming apparatus. To do.

The image processing method according to claim 8 is
An image processing method for previewing image formation by an image forming apparatus by a predetermined display apparatus, which receives an image signal processed by a pseudo halftone processing circuit constituting the image forming apparatus, and displays the image signal. It is characterized in that conversion processing is performed so as to be displayed on the means.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a block diagram of a system including an image processing apparatus according to an embodiment of the present invention. In FIG. , 200 is a host computer connected to them. In FIG. 1, 1 is a platen glass,
Reference numeral 2 is an original pressure plate for pressing an original placed on the original glass 1, 3 is a halogen lamp for illuminating the original, 4,
Numerals 5 and 6 are mirrors for forming an image on the color image sensor 8 by reflected light from the document illuminated by the halogen lamp 3, and numeral 7 is an image forming lens arranged in the optical system. The color image sensor 8 is, for example, R (red), G (green).
n) and B (blue) 3-line CCD sensor. Reference numeral 9 denotes an image having predetermined characteristics in a color image area such as black characters, as well as performing various correction processes to convert the RGB image information photoelectrically converted by the color image sensor 8 into a digital signal and faithfully reproduce the original. An image processing circuit for detecting a portion, which is configured by hardware such as a logic circuit. Reference numeral 10 denotes an image formation control circuit for generating a signal for driving the inkjet head 34 based on the image data that has been subjected to a predetermined process in the image reading unit 100. The inkjet head 34 discharges ink onto the surface of the recording paper 31 to record the original image in full color. Therefore, the ink recording colors are cyan (C), magenta (M), yellow (Y), and black (K). It corresponds to.

Reference numeral 30 is a paper cassette for storing recording papers, 32 is a paper feed roller for feeding the recording papers 31, 33 is a carrying roller for carrying the fed recording papers, and 35 is a paper feed roller. Is a platen provided at a position facing the inkjet head 34, 36 is a paper discharge roller for conveying the recording paper to the outside of the machine, and 37 is a paper discharge tray for receiving the discharged recording paper.

In the above structure, the original is illuminated by the halogen lamp 3 while the original is placed on the original glass 1, and the surface of the original is scanned by moving the optical system member. At this time, the reflected light from the original surface
An image is formed on the color image sensor 8 through the image forming lenses 5 and 6. Red (R), green (G), and blue (B) filters are formed on the light receiving surface of the color image sensor 8, and these three color filters have a predetermined sensor cell pitch (400 dpi in this embodiment). Are arranged so that The color image sensor 8 converts the reflected light from the original surface into electric signals of three components of RGB, and an A / D converter (not shown) outputs each color of RGB 8bi.
It is converted into a digital signal of t and supplied to the image processing circuit 9.

FIG. 2 shows the configuration of this embodiment centering on the image processing circuit 9.

First, a normal copy operation will be described.

The image signal converted into the digital signal is subjected to characteristic correction (shading correction) of the reading optical system by the shading correction circuit 41, and the thinnest image signal becomes FFH and the darkest image signal becomes 00H. The image signal subjected to the shading correction is input to the input masking circuit 42.
Thus, the sensitivity of the color separation filter of the color image sensor 8 is corrected and output as a normalized signal of RGB (each 8 bits). Further, the input masking circuit 42 generates and outputs a brightness signal representing the brightness information of the original from the input image signal. The normalized RGB image signal and luminance signal are converted by the logarithmic conversion circuit 43 into C (cyan), M (magenta), and Y (yellow) signals representing density information for each color component. Next, CMY (8 bits each)
In the minimum value extraction circuit 44, the image signal changed to the minimum value Min among the image signals C, M, and Y
(C, M, Y) is selected, and the selected minimum value Min
C, M, Y, Min with (C, M, Y) as the undercolor signal
The signal configuration is changed to (C, M, Y) and sent to the next process. The image signal added with the minimum value signal is converted by the output masking circuit 45 into an image signal of four colors of C, M, Y, and K (black) after being corrected by the coloring characteristics of ink. Next, in the γ correction circuit 46, γ conversion is performed so as to obtain the density and color balance set in advance by the user, and then the pseudo halftone processing circuit 47 performs pseudo halftone processing (for example, error diffusion and average density storage). Method and the like) are applied, and a predetermined number of bits (each 1 in this embodiment) is applied.
(bit) image signal and supplied to the recording control circuit 10. A black character detection circuit 50 detects a black character portion in the original based on the RGB signals from the input masking circuit 42. Based on the detection signal, the pseudo halftone processing circuit 47 converts the CMY data into 0 so as to prohibit the printing with the CMY ink on the black character portion. The preview described later is performed by the signal processed based on the black character detection.

CMYK supplied by the image processing circuit 9
Image signal of CMYK in the process delay circuit 48.
After a delay process of a time corresponding to the interval of the inkjet head 34 corresponding to each color is performed, the pulse conversion circuit 49
Is converted into a head driving pulse to drive each inkjet head 34, and each ink of C, M, Y, and K is ejected onto the recording paper 31 to form a full-color image.

In this way, the color copying machine (composed of 100 and 101) according to one embodiment of the present invention sequentially visualizes the document information read by the color image sensor 8 by the ink jet method to document information. The recording and reproduction of is performed.

Further, the color image reading section 100 is provided with the host computer 2 via the video interface 150.
00, and the Y, M, C, Y, and K binary signals output from the pseudo halftone processing circuit 47 can be transmitted to the host computer 200. Conversely, image formation based on a binary signal from the host computer 200 is also possible.

The host computer 200 has a CPU 51 for performing processing based on a program, a RAM 52 used as a work area, and an RO for storing program data.
An M53, an external input unit 54 for inputting a program stored in a medium such as a floppy disk, and the like.

The image from the host computer 200 can be displayed on the CRT monitor 201.

The color CRT monitor 201 is normally R,
G and B (red, green, blue) are used for color expression. The monitor 201 expresses each of R, G, and B signals by 8 bits, that is, 24 bits in total, and is called a full-color display, and can reproduce 16.77 million colors per pixel.

On the other hand, when one pixel of RGB is represented by 8 bits, only 256 colors can be represented per pixel, but in the reproduction image confirmation such as a preview, 256 colors are displayed.
Color expression is often sufficient.

In this case, if the image signal fetched from the color image reading unit 100 is an R, G, B 24-bit full-color image, the data amount is large and the transfer time through the video interface 150 is long, and the computer 20 is used.
In the case of 0, since binarization processing is required, there is an inconvenience that it takes more processing time.

Therefore, in the present embodiment, the Y, M, and
The binary signals of C and K are taken into the host computer 200 via the video interface 150, and after the image processing by the application software described later, the CRT 201
Display a preview on.

FIG. 3 is a flow chart showing the procedure of the preview process. This procedure is performed by the host computer 20
0 is realized by a program of application software supplied by the external input 54.

First, in S101, the image reading unit 10
Each part is controlled within 0. The CPU (not shown) is instructed to read the image. In S102, the Y, M, C, and K binary signals generated by the hardware circuit in the image reading unit 100 are input to the video interface 1
RAM 5 in the host computer 200 via 50
2 is sequentially taken in for each pixel.

In S103, the obtained Y, M, C,
CR K binary signal (resolution is 400 dpi for each color)
The resolution (the number of pixels) and the number of gradations of T201 are combined and converted into, for example, 50 dpi 256 colors.

Here, the algorithm of the pseudo-halftone processing performed by the pseudo-halftone processing circuit 47, the size and the resolution of the target image are determined by the host computer 2 via a control line (not shown).
00 is notified. The resolution (number of pixels) of the CRT 201 is stored in the ROM 53 of the contents of the host computer in advance, and the above-mentioned conversion is performed based on these parameters.

In step S104, a preview display is performed on the CRT 201 based on the multivalued R, G, and B signals.

As described above, according to this embodiment, when the preview display is performed on the host computer 200, the hardware of the copying machine main body side (100, 101) is used for binarization, and the processing result is displayed. Since it is transferred, high-speed preview display is possible by effectively utilizing the functions of the main unit.

Further, it is not necessary for the application software on the main body side to have an algorithm for binarization processing of the main body of the copying machine, and the creation of the program can be simplified.

(Embodiment 2) In the above-mentioned embodiment, the color copying machine converts the image signals read by R, G and B to C,
After converting to M, Y and K, each is binarized so CRT
It cannot be directly reproduced on the monitor 201. Therefore, in the present embodiment, the R, G, B signals are not converted into CMYK and the respective processing circuits of the image processing circuit 9 are passed through as they are as the R, G, B signals, and the binarization processing circuit (pseudo halftone processing circuit 47). Outputs a binary signal of RGB subjected to pseudo halftone processing. That is, in this embodiment, the logarithmic conversion circuit 43 to γ conversion circuit 46 are through. The R, G, and B binary signals output from the pseudo halftone processing circuit 47 are sent to the host computer 200 via the video interface cable 150, converted into a predetermined number of pixels, and then the CRT 201.
Is displayed in.

At this time, the binary signal may be converted into a multi-level signal having two stages of 0 and FF, for example.

As described above, according to this embodiment, the binarization processing circuit of the digital copying machine can be effectively used.

That is, the digital copying machine used in this embodiment is intended for binary recording such as an ink jet recording method, and the binary image signal used for recording is directly displayed on the CRT monitor 201, so that the image to be printed is printed. Can be previewed efficiently.

As described above, according to the embodiment of the present invention, an image signal obtained by reading an original is subjected to pseudo halftone processing using the image circuit (hardware) of the copying machine main body, so that a large amount of multi-valued data is obtained. Image data can be processed and transmitted at high speed. Further, since the pseudo halftone processing of the main body of the copying machine is performed, it is possible to preview an image almost identical to the output print image on the CRT monitor. Although the CRT monitor is used in the above example, for example, a so-called FLC is used.
When a display device for displaying a binary signal such as D is used, it is not necessary to change the RGB multi-valued signal as described above.

[0035]

As described above, according to the present invention, high-speed transmission and high-speed processing can be performed at the time of processing by the host computer by utilizing the hardware provided in the image forming apparatus main body side.

[Brief description of drawings]

FIG. 1 is a diagram showing a system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an image processing circuit according to an embodiment of the present invention.

FIG. 3 is a diagram showing a preview display unit according to the embodiment of the present invention.

[Explanation of symbols]

 41 shading correction circuit 43 logarithmic conversion circuit 45 output masking circuit 47 pseudo halftone processing circuit

Claims (8)

[Claims] 1. A processing unit for performing a pseudo halftone process on an input image signal, an image forming unit for forming an image using the pseudo halftone signal output from the processing unit as a recording signal, and the pseudo An image processing apparatus comprising: an output unit that outputs a halftone signal to an external device. 2. The pseudo halftone signal output from the processing means has different color components when supplied to the image forming means and when supplied to the output means. 1. The image processing device according to 1. 3. The input image signal is R, G, B
The multi-valued image signal of Y, M,
The image processing apparatus according to claim 1, wherein an image is formed based on a binary image signal of C and K. 4. The image processing apparatus according to claim 1, wherein the processing unit performs a density preservation type pseudo halftone process. 5. An image processing apparatus for processing an input image signal to create a recording image signal, and for previewing an image formed by an image forming apparatus for forming an image on a medium by a recording means. The image forming apparatus further comprises interface means for extracting the recording image signal from the image forming apparatus, and the interface means obtains the recording image signal obtained by performing pseudo halftone processing in the image forming apparatus. An image processing apparatus, characterized in that 6. The image processing apparatus according to claim 5, further comprising display means for soft copying an image based on the recording image signal. 7. The image processing apparatus according to claim 5, further comprising a conversion unit that performs a conversion process to match the number of pixels and the number of gradations of the recording image signal with the display unit. 8. An image processing method for previewing image formation by an image forming apparatus on a predetermined display apparatus, comprising: receiving an image signal processed by a pseudo halftone processing circuit constituting the image forming apparatus; An image processing method, wherein conversion processing is performed to display the image signal on the display means.