JPH0237370A - Image processor - Google Patents

Abstract

PURPOSE:To switch to monochromic color from full color, for instance, at a high speed and with high accuracy by simple constitution by providing a 1st means taking out an ND signal from a supplied picture signal and a 2nd means executing operation different from that of the 1st means and a selecting means selecting the two means. CONSTITUTION:The image processor is provided with the 1st means 3 taking out the ND signal from the supplied picture signal, the 2nd means 1 whose part is provided in parallel with the 1st means and which processes the supplied picture signal in a way different from that of the 1st means 3, and the selecting means selecting the 1st means 3 and the 2nd means 1. An ND signal generating circuit 3 is a circuit to generate the ND signal required for monolithic output from signals C1, M1 and Y, and it can be readily constituted by using a combination of a look-up table, a multiplier and an adder, just like a masking UCR circuit1. Under the simple constitution, an image of monochromic color can be switched to that of full color, for instance, at high speed and with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus capable of processing a mixture of monotone images and full-color images in real time.

[Conventional technology]

In recent years, color copying machines have been able to achieve higher image quality by introducing digital image processing, and so-called digital color copying machines with recording devices such as LBPs (laser beam printers) and inkjet printers are rapidly increasing. It has become popular.

Along with this, various needs have required higher functionality of color copying machines, one of which is the ability to convert a part of a full color image into a monochrome image.

[Problem to be solved by the invention]

As a means for realizing the above-mentioned functions, a method can be considered in which a part of the digital image is stored in a memory and the digital image is processed by a computer.

However, this method has disadvantages in that it requires a large amount of memory capacity, increases the cost of the device, and takes a long processing time.

Also, in order to realize the above function in real time, masking UC
There is a method of having multiple types of R processing coefficients and switching these coefficients in real time.

In this method, masking or U
Since, for example, a register is required to hold the CR coefficient, there is a drawback that the circuit scale of the masking UCR circuit increases.

In addition to outputting monochrome images, masking UCR circuits can actually be used for color correction of halftone images and silver halide images, so it is difficult to perform such color correction in real time on the same print. Furthermore, there is a problem in that the number of sets of coefficients increases, further increasing the circuit scale.

SUMMARY OF THE INVENTION It is an object of the present invention to solve this problem and provide an image processing device that has a simple configuration and can switch between monochrome and, for example, full color at high speed and with high accuracy.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a first means for extracting an ND times signal from a given image signal, at least a part of which is provided in parallel with the first means, and a The present invention is characterized in that it has a second means that performs a process different from the first means, and a selection means that selects the first means and the second means.

[For production]

In the above configuration, the selection means selects the first means and the second means, at least some of which are provided in parallel.

〔Example〕

Before explaining the embodiments of the present invention, the comparison means of the present invention will be explained.

A case will be described in which there are multiple coefficients for masking and OCR processing.

For example, the output signal is C (cyan) and 1M (magenta).

Y (yellow), Bk (gray), and the input signal is C.
+ (cyan), Ml (magenta), Yl (yellow),
X 1 (min (C1+ M It Y
+)), the equation for masking UCR processing is as follows.

However, a, ... a44 is the coefficient formula (1), and to output a signal for four full colors,
UCR is performed by setting all+a22+a33+a44 as a positive coefficient and the coefficient of a14+a24+a34 as a negative value, and the remaining coefficients may be selected according to the color characteristics of the ink and toner of the printer.

Similarly, when printing in single color C (cyan) using formula (1), the coefficients of aII + a12 r a13 are set to 0, for example.
．． 33 to generate a color signal corresponding to an ND multiplied signal, and the remaining coefficients 814 to a44 may be set to 0.

Therefore, in order to obtain an image in which a full-color image and a monochrome image are mixed in real time, a II to a of the above formula (1) must be
It would be a good idea to have multiple 44 coefficients and change them in real time. For example, in the same copying operation, a full color image and a C(
In order to mix and output a total of four types of images: cyan (cyan) single color, M (magenta) single color, and Y (yellow) single color images, four sets of coefficients are prepared and images are output while switching between them. Become.

Therefore, a register for holding a plurality of sets of such coefficients is required, resulting in a problem that the scale of the masking and UCR circuits increases.

An embodiment that solves this problem will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The color image signal is obtained from a color image scanner, etc.
It is decomposed into color components of + (cyan), Ml (magenta), and Yl (yellow), and is input to the masking UCR circuit 1, the fish oil output circuit 2, and the ND signal generation circuit 3, respectively.

The fish oil extraction circuit 2 is a circuit for extracting the X1=min (C1, Ml, Yl) signal, and is composed of a comparison circuit and a selector. The extracted X1 signal is input to the masking UCR circuit 1 and subjected to the arithmetic processing shown in equation (1) to produce C (cyan), a four-color full-color signal.

M (magenta), Y (yellow), and Bk (black) signals are output. The masking UCR circuit 1 can be easily constructed using a look-up table or a combination of multipliers and adders.

The ND signal generation circuit 3 is a circuit for generating an ND times signal necessary for monotone output from the C, M, Y signals, for example, ND=b, xC, +b2xM, +b3xY,
(2) Formula, , b2. b3 performs an operation given by a coefficient formula.

Similarly to the masking UCR circuit 1, the ND signal generation circuit 3 can be easily configured using a combination of a look-up table, a multiplier, and an adder.

Selectors 4 to 7 are, for example, 5N74LS157 manufactured by TI.
It is a selector circuit like this, and it is a circuit that can perform data switching by two people and control the output to 0. Selector 4~
・The data switching input terminal S of 7 has C8゜MS, Y
S, BkS, output O control signal input terminal G has CG, M
G, YG, and BkG control signals are input and changed in synchronization with image input to control full color image and monotone image output.

Next, the operation of the circuit shown in FIG. 1 will be explained using FIGS. 2 to 4.

FIG. 2 is an example of a desired output image. For input data of an entire full-color image, C
(cyan) single color, M (magenta) single color, Y (yellow)
An example is shown in which a monochrome, Bk (black) monochrome output image is obtained.

FIG. 3 is a diagram showing signal changes of each control signal input to the S terminals of selectors 4 to 7. Normally, the data of the A input terminal is selected, and the ND times signal is selected in the shaded area shown in the figure. This shows that the CS, MS, YS, and BkS signals are changed in accordance with the input image.

FIG. 4 is a diagram showing the signal changes of each control signal input to the G terminals of selectors 4 to 7. Normally, the output is enabled, and the output of selectors 4 to 7 is output O in the shaded area.
7 output control, CG, MG, YG.

This shows that each BkG control signal is changed in accordance with the input image.

In the figure, for example, in the part where C (cyan) monochrome output is performed, only the C' signal is output using the ND multiplied signal, and the M', Y', and Bk' signal outputs are controlled so that they are all 0. Is going.

In this way, it can be seen that monotone images of multiple colors can be obtained simultaneously under real-time control without changing the coefficients of the masking UCR calculation.

In addition, in the explanation of the operation in FIGS. 2 to 4, only monochrome images of C, M, Y, and Bk were explained as monochrome images, but for example, ND double signals C and M can be simultaneously printed, that is, blue It goes without saying that it is easily possible to create a monotone image by mixing ink colors.

[Other Examples]

In the embodiment described above, an example of simultaneous output of four colors has been taken up, but for example, if a one-drum type laser beam printer is used as an output device, C, M, etc.

Since it is sufficient to sequentially output images for each color such as Y and Bk, it is possible to further reduce the scale of the hardware.

An example of the circuit is shown in FIG.

In FIG. 5, masking UCR circuit 11. The black extraction circuit 12, the ND signal generation circuit 13, and the selector 14 are constructed as shown in 1. in FIG. 2. These circuits correspond to the circuits shown in 3.4.

The masking UCR circuit 11 calculates Z=d for equation (1).
, XC, +d2XM, +d3XY, +d4XX, (3)
Any circuit that can calculate Equation 6% will suffice, and C'M' in Figure 1
, Y', Bk', the coefficients of d, -d4 are changed for each output color, and the control signal Zs is output.

It is sufficient to change the control of ZG as shown in FIGS. 3 and 4 and output it.

Fish oil output circuit 12. The ND signal generation circuit 13 may be the same as the circuit shown in FIG.

In this way, in this example, the circuit size of the masking UCR circuit can be taken care of, and the number of selectors can be kept the same, thereby reducing the circuit scale.

[Other Embodiment 2] In the above two embodiments, the ND double signal is directly sent to the selector 4.
-7, 14, but in order to adjust the color tone when combining cyan and magenta, for example, each color is multiplied by a different coefficient and weighted, and then input to selectors 4-7,
14 may be input.

[Other Embodiment 3] Other Embodiment 1 was an example in which images were output one page for each color, but the present invention can also be applied to an example in which one color image is serially transferred in units of 4 clocks. Adaptable.

For example, in FIG. 5, in order to serially output a color image in Y, M, C, Bk order as output 2, the masking UCR circuit 11 and the ND signal generation circuit 1
3, the case where an image is output in synchronization with the image clock VCK as shown in the timing chart shown in FIG. 6 will be explained. In such a case, the timing generation circuit 20
The C3I and C3O signals output from the C3I and C3O signals are signals indicating that cyan is output when the value is 11, magenta is output when the value is 10, yellow is output when the value is 01, and black is output when the value is OO. It can be used to synchronize pixels and colors by sending the image data together with the image data to each processing circuit including the image data processing circuit. ZS added to selector 14.

By controlling the ZG multiplied signal in synchronization with the image clock VCK as shown in FIG. 6, monotone images and full color images can be easily obtained as shown in FIG. In this case, the selector 14 selects the B input when the S terminal input=1, and outputs 0 when the G terminal input=1.

Incidentally, FIG. 7 is a block diagram showing a configuration for generating the signals shown in the timing chart of FIG. 6.

In FIG. 7, 20 is a timing signal generation circuit,
It generates a clock VCK for image data transfer and C3I and C3O signals for indicating the type of data to be transferred.

21 receives VCK, C3O, C3I, and area signals for switching between monochrome and full color, and Z as shown in FIG.
This is a select signal generation circuit that outputs S and ZG.

As described above, according to the embodiment, it is possible to output an image containing a mixture of monotone and full color images in real time without using multiple sets of circuit coefficients of the masking UCR circuit. Particularly, when a polynomial that uses up to second-order and third-order terms is used in the masking process, the number of coefficients increases, so the effects of the present invention are significant.

In the embodiment described above, the circuit for extracting the ND times signal (Fig. 1 3, Fig. 5 13), masking, OC
It is constructed completely separately from the R circuit (Fig. 1, 2, 3, Fig. 5, 11.12), and both circuits are provided in parallel. Even if there is, the present invention can be applied.

Further, although a circuit for masking or UCR is used as a circuit having a function different from the circuit for generating an ND multiplied signal, the circuit is not limited to this, and may be a circuit for performing other processing.

Further, in this embodiment, the ND multiplied signal is obtained based on the calculation formula shown in the above-mentioned formula (2). It may be obtained based on.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to perform switching between monochrome and other images, such as full color, quickly and with high accuracy with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a color processing circuit according to an embodiment of the present invention; FIG. 2, FIG. 3-a, FIG. 3-b, FIG. 3-c, and FIG.
Figure d, Figure 4-a, Figure 4-b, Figure 4-c, Figure 4-d
5 is an explanatory diagram of processing operation, FIG. 5 is a circuit configuration diagram of another embodiment of the present invention, FIG. 6 is a control timing chart for serial color image signals, and FIG. FIG. 3 is a block diagram for generating each of the illustrated signals.

Claims (3)

[Claims] (1) First step to extract the ND signal from the given image signal
means, at least a part of which is provided in parallel with the first means;
An image processing apparatus comprising: second means for performing processing different from the first means on a given image signal; and selection means for selecting the first means and the second means. (2) The image processing apparatus according to claim 1, wherein the second means is a means for performing color masking processing. (3) The image processing apparatus according to claim 1, wherein the second means is a means for performing black extraction processing.