JPH11234533A - Image processing unit and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain effective utilization of a memory area without excessive data storage by storing color image data consisting of a plurality of color components while minimizing a quantity of the image data of color components discriminated not valid. SOLUTION: A differential adder 23 accumulates a difference between a value of a pixel and that of adjacent pixels for each color component of received image data, and a comparator 24 compares the accumulated value with a prescribed threshold value. When the accumulated value exceeds the threshold value, a filp-flop 25 outputs a storage enable signal at an L level to instruct storage of image data of the color component after compression. On the other hand, when the accumulated value is less than the threshold value, the slip-slop 25 outputs a storage enable signal at an H level to instruct storage of only a mean value of image data of the color component calculated by a mean value calculation section 26.

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 and method, and more particularly, to an image processing apparatus and method for compressing and storing image data.

[0002]

2. Description of the Related Art With the development of image processing technology in recent years, image processing apparatuses that realize the functions of a plurality of devices such as copiers, printers, facsimile machines, etc. with one apparatus have become widespread as so-called digital multifunction peripherals. I have. In a conventional multifunction device, a plurality of image data is input and temporarily stored in its own memory, thereby classifying the plurality of image data,
In addition, there has been proposed a device that controls the output order and realizes a so-called electronic file function and an electronic sort function.

In such a high-performance image processing apparatus, the amount of image data stored in the apparatus tends to increase, and color image data is often handled. Therefore,
In order to effectively use the memory resources in the apparatus, it is common to compress the image data before storing it.

Further, when an enormous amount of data such as a color image is compressed and stored in a memory in an image processing apparatus,
There is also known a method of improving the compression ratio by performing compression after converting the format of image data.

In addition, a method has been proposed in which, when storing color image data composed of a plurality of color components, the image data for the specific color component is deleted and not stored, thereby reducing the amount of image data. .

[0006]

However, in the above-described conventional image processing apparatus, the method of erasing and storing image data of a specific color component is effective only when the image data to be processed has predetermined characteristics. Met. That is, since the target color component to be erased is determined in advance, for image data including a large amount of the color component to be erased and having a large amount of change for each pixel, all the color components to be erased are erased. As a result, the image data is stored as image data that does not retain the features of the original image.

That is, a method of erasing a specific color component when storing color image data is not practical because of lack of versatility.
It was necessary to store image data for all color components. Therefore, especially when a large amount of color image data is processed, an enormous amount of image data is transferred to the memory, so that the memory area cannot be used effectively. In some cases it caused a situation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and minimizes the amount of color component image data determined to be invalid for color image data composed of a plurality of color components. By remembering
An object of the present invention is to provide an image processing apparatus and a method thereof that enable effective use of a memory area without performing excessive data storage.

[0009]

As one means for achieving the above object, the image processing apparatus of the present invention has the following arrangement.

That is, there are provided input means for inputting image data composed of a plurality of color components, compression means for compressing the image data, and storage means for storing the image data compressed by the compression means. An image processing apparatus, comprising: a determination unit that determines whether or not the image data should be stored in the storage unit for each color component; and a storage mode of the image data in the storage unit according to a determination result by the determination unit And control means for controlling

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

First Embodiment Apparatus Configuration FIG. 1 is a block diagram showing the configuration of an image processing system according to this embodiment. In the figure, 1 is a scanner circuit for taking in an image, 2 is a printer device for printing out an image, 3 is a facsimile circuit capable of transmitting and receiving an image, 4 is a page created by a host 6 and transmitted through an interface circuit 5 This is a PDL circuit that develops description language (PDL) data into a bitmap image. The interface circuit 5 performs bidirectional communication between the host 6 and image data. Reference numeral 7 denotes an input / output control circuit, and a buffer memory circuit 8
Also, it controls writing and reading to and from a storage device 10 such as an MO drive or a hard disk via the image conversion circuit 9. A determination circuit 11 determines whether or not an image is stored in a storage device, which is a feature of the present embodiment. Reference numeral 12 denotes a system control circuit that controls the entire image processing system and includes a CPU and the like.
The overall control is performed according to the program stored in the OM 13. Reference numeral 14 denotes an MMI (Man-Machine Interface) circuit such as an operation unit for inputting various settings and the like regarding the image processing system by the user. [Outline of Input / Output Operation] Hereinafter, an input / output operation of image data in the image processing system of the present embodiment having the above configuration will be described.

First, the input processing of image data will be described.

When an image reading instruction is given to the scanner circuit 1 under the control of the system control circuit 12, the scanner circuit 1 reads an image as digital image data. The read image data is stored in the buffer memory circuit 8 under the control of the input / output control circuit 7.

On the other hand, the read image data is also supplied to the determination circuit 11 via the input / output control circuit 7. In the determination circuit 11, a feature is extracted for each color component of the image data, and is compared with, for example, a condition set in advance by a user's setting, to determine whether or not to store for each color component. . And the system control circuit 12
The following instruction is given to the input / output control circuit 7 based on the determination result. That is, for the color component determined to be stored, the image data is read out from the buffer memory circuit 8 and supplied to the image compression circuit 9, subjected to compression processing and the like, and then stored in the storage device 10. For the color components not determined to be stored, the subsequent processing is interrupted so that the image data of the buffer memory circuit 8 is not stored in the storage device 10.

Here, when there are a plurality of original images,
For example, it is determined by a document placement sensor of the automatic document feeder provided in the scanner circuit 1 whether or not there is a document image to be read, and if so, the operation described above is repeated. At this time, the plurality of image data are stored in the storage device 1
However, the address of each image data is managed by the system control circuit 12.

Next, output processing of image data in the present image processing system will be described.

The system control circuit 12 reads out the image data stored in the storage device 10 by instructing the input / output control circuit 7 and supplies it to the image conversion circuit 9 to perform decompression processing. To memorize. Thereafter, the image data read from the buffer memory circuit 8 is supplied to the printer device 2 to perform print output. If there are a plurality of image data, the above-described operation is repeated to print out.

Here, if only a part of the image data read from the storage device 10 is to be printed out, the processing is terminated by the above operation, but if a plurality of copies are to be printed out, the image data stored in the storage device 10 is to be output. Are read out in the order in which they are stored. For example, when the rotation sort is designated by the MMI circuit 14, the printout is performed after the rotation process is appropriately performed. Note that the rotation sort means, for example, that when a plurality of copies are superimposed and printed out, for example, rotation discharge is alternately performed for each copy in order to easily determine a break between the copies. In the present embodiment, when execution of rotation sorting is specified by the MMI circuit 14, the rotation processing is performed by the system control circuit 12 controlling the input / output control circuit 7.

The above operation is repeated until the last copy is printed out.

In the present embodiment, if the image data being processed is determined to be a specific image by the determination circuit 11, a limit is imposed on the accumulation of the image data in the storage device 10. That fact may be stored in the storage device 10 as supplementary information. This additional information is, for example,
The fact that the image data has been restricted has been
It can be used to notify the user via.

In the above description, an example has been described in which image data is read out in accordance with the order of storage. However, the present embodiment is not limited to this example. For example, image data is output in a different order from the time of input. Is also good. For example,
In the case of creating a pamphlet by saddle-stitching printing paper, etc.,
It is necessary to perform print output in a different order. The feature determination process for each color component in the determination circuit 11, which is a feature of the present embodiment, will be described in detail below.

In the present embodiment, R (red), G (green), B
(Blue) luminance data in the input / output control circuit 7
A system in which density data of (cyan), M (magenta), Y (yellow), and K (black) are converted, the CMYK data is stored in the storage device 10, and then output by the printer device 2 will be described.

FIG. 2 shows a circuit configuration in which the determination circuit 11 checks the amount of change in the input CMYK image data and determines whether or not the storage of the image data in the storage device 10 is permitted. It is. In the present embodiment, C
The determination process is performed for each of the MYK color components by the same method. Therefore, for example, the circuits shown in FIG. 2 may be provided for each of the CMYK color components, and the simultaneous processing may be performed.

In FIG. 2, the input image data is 2
Input to two flip-flops (FF) 21 and 22;
Image data of one pixel is output each time the video clock VCLK rises. Therefore, the FFs 21 and 22
Is delayed by the VCLK cycle, the output signals of the FF21 and the FF22 are image data of pixels adjacent to each other.

Each time the image data is transferred, the difference adder 23 sequentially adds the absolute value of the difference between the output signals of the FFs 21 and 22. Also, the difference adder 2
The difference accumulated value output from 3 is sent to the comparator 24.
The comparator 24 compares the accumulated difference value with a preset threshold value, and when the accumulated difference value exceeds the threshold value,
The level is output to the FF 25.

The output value of the FF 25 is initialized to an H level by a vertical synchronization signal VSYNC which is a trigger signal for transferring image data for each color component. The VSYNC in the present embodiment is output from the input / output control circuit 7 only once every time image data is transferred for each color. FF25
Outputs a storage permission signal for permitting storage of the image data in the storage device 10. This storage permission signal indicates that the storage is not permitted at the H level and that the storage is permitted at the L level. After the start of the transfer of the image data, if the output of the comparator 24 does not become H level, the FF 25 keeps outputting H level and does not permit the image storage. On the other hand, when the output value of the comparator 24 becomes H level, the FF 25 outputs L level and permits image storage. That is, in the present embodiment, when the accumulated value of the change amount of the image signal is equal to or more than the predetermined value, it is determined that a valid image signal is input, and the storage in the storage device 10 is permitted. On the other hand, when the cumulative value of the change amount of the image signal is equal to or less than the predetermined value, it is determined that an invalid image signal is input, and the storage in the storage device 10 is not permitted.

The output signal of the FF 21 is also sent to the average value calculation section 26. In the average value calculator 26, F
The image data sent from F21 is sequentially added in synchronization with VCLK, the rising edge of VCLK is counted, the number of pixels is calculated, and the average value (image average value) of the image data is calculated and output. Note that the average value calculation unit 26 also uses the VS
By being initialized by the YNC, an image average value of the same color component is output.

The storage permission signal output from the FF 25 is
It is input to the input / output control circuit 7 via the system control circuit 12. In the input / output control circuit 7, when the storage permission signal changes to L level, the image data is transferred to the image compression circuit 9, subjected to image compression, and then stored in the storage device 10. On the other hand, when the storage permission signal remains at the H level, the input / output control circuit 7 does not transfer the image data to the image compression circuit 9 and the final value of the image average value output from the average value calculation unit 26 (all Is output to the storage device 10 in an uncompressed state.

The concept of the process of storing image data in the above-described embodiment is shown in the flowchart of FIG.

Referring to FIG. 1, image data read by the scanner circuit 1 is input in step S101, and it is determined in step S102 whether the image data is to be stored in the storage device 10 in the determination circuit 11. That is, the amount of change in the image data of each color component is acquired, and when the amount of change exceeds a predetermined value, the image data is determined to be stored and a storage permission signal is output at L level. Then, in step S103, the image compression circuit 9 performs a predetermined compression process on the image data, and then stores the image compression data in the storage device 10 in step S105. On the other hand, if the change amount of each color component is equal to or less than the predetermined value in step S102, the image data is not stored and a storage permission signal is output at H level, and the process proceeds to step S104. In step S104, the average value of the image data of each color component generated in the determination circuit is adopted as the image data, and the average value is stored in the storage device 10 in step S105.

As described above, the image data of the color component having a large change amount is compressed and stored, and the image data of the color component having a small change amount is stored only with the average value. Regarding the component image data, the amount of data to be stored can be minimized. [Storage Data Structure] FIG. 4 shows an example of a data structure stored in the storage device 10. In the present embodiment, the case where the image compression data is transferred to the storage device 10 as described above,
In some cases, the image average value is transferred, but it is necessary to be able to grasp this distinction in image units. Therefore, in the present embodiment, image data is stored in a data structure accompanied by image management information as shown in FIG. FIG. 4 (a)
Indicates the structure of the first and second image data stored in the storage device 10. According to FIG. 4A, the first image data is compressed and held in the order of C, M, Y, and K components, and the second image data is stored in the M
As for the components, it is understood that the image average value data 302 is stored instead of the image compression data. Here, the image average value data 302 is an average value of the M component in the second image data 2, and its capacity corresponds to one pixel. That is, in FIG. 4A, only the M component in the second image data is prohibited from being stored in the storage device 10 by the determination circuit 11, and the other components are permitted. Here, FIG. 4B shows the details of the data structure of the compressed image data storage area 301 of the C component in the first image data shown in FIG. Similarly, the second
FIG. 4C shows details of the image average value data 302 of the M component in the image data. Each of FIGS. 4B and 4C has an image management area indicating whether the stored image data is compressed image data or image average value data.

When outputting the image data stored in the storage device 10 as described above, the color component in which the image data compressed by the image compression circuit 9 is stored is subjected to a corresponding decompression process to perform image expansion. Data is output, and all the pixels are uniformly output as the average value for the color component in which the average value data is stored. Even if an image is recorded on a recording medium in the printer device 2 based on the image data of each color component reproduced in this way, for example, the pixel value of the color component with little image change is averaged. Therefore, the color of the entire recorded image can be maintained, and is substantially equal to the original image read by the scanner circuit 1.

As described above, according to the present embodiment,
The amount of change for each color component of the image data stored in the storage device 10 is extracted, and it is not effective to determine whether to compress and store the image data or to store only the average value based on the result. The image data amount of the color component can be minimized, and the storage capacity of the storage device 10 can be effectively used.

<Second Embodiment> Hereinafter, a second embodiment according to the present invention will be described.
An embodiment will be described.

In the first embodiment described above, an example in which the present invention is applied to an image processing system has been described. In the second embodiment, an example in which the present invention is applied to an image processing apparatus that encodes read color image data, stores the encoded color image data in a storage unit, and outputs the encoded image data will be described.

FIG. 5 is a side sectional view of a color copying machine as an example of the image processing apparatus according to the second embodiment. In FIG. 1, reference numeral 201 denotes a platen glass on which a document 202 to be read is placed. The original 202 is illuminated 20
Then, an image is formed on the CCD 208 by the optical system 207 via the mirrors 204 to 206. Further, the mirror 204 and the illumination 203 are mechanically driven by the motor 209.
The mirror unit 210 including the
5, the second mirror unit 211 including the speed V / 206 has a speed V /
2, the entire surface of the document 202 is scanned.

Reference numeral 212 denotes an image processing unit which processes the read color image as an electric signal for each color component and outputs the processed signal as a print signal.

Reference numerals 213 to 216 denote semiconductor lasers for the respective color components. The semiconductor lasers are driven by the respective print signals output from the image processing unit 212, and the laser beams emitted by the respective semiconductor lasers are transmitted by polygon mirrors 217 to 220. A latent image is formed on the photosensitive drums 225 to 228.

Reference numerals 221 to 224 denote developing units for developing latent images with toners of K, Y, C, and M, respectively. The developed toners of the respective colors are transferred to recording paper to form full-color images. Print output is made.

The recording paper fed from one of the paper cassettes 229 to 231 and the manual feed tray 232 is attracted onto the transfer belt 234 via the registration rollers 233 and is conveyed. Synchronous with this paper feed timing, the toner of each color is developed in advance on the photosensitive drums 225 to 228, and the toner is transferred to the recording paper as the recording paper is transported.

The recording paper to which the toner of each color has been transferred is separated and conveyed from the transfer belt 234, the toner is fixed on the recording paper by the fixing device 235, and is discharged to the discharge tray 236.

In FIG. 5, reference numerals 201 to 211 denote components relating to image reading, and correspond to the scanner circuit 1 shown in FIG. 1 in the first embodiment. FIG.
The image processing unit 212 corresponds to each of the circuit configurations 8 to 12 including the image input / output control circuit 7 and the storage device 10 shown in FIG. Further, reference numerals 213 to 236 in FIG. 5 indicate a configuration for printing and outputting an image, and correspond to the printer device 2 shown in FIG.

That is, in the image processing apparatus shown in the second embodiment, the amount of change for each color component constituting the image data is extracted in the same manner as in the first embodiment, and the image data is compressed according to the result. By determining whether to store the image data or only the average value, it is possible to minimize the image data amount of the ineffective color component and to effectively use the storage capacity of the storage device 10.

Third Embodiment Hereinafter, a third embodiment according to the present invention will be described.
An embodiment will be described.

In the third embodiment, an example in which the present invention is applied to a general-purpose information processing device or system will be described.

FIG. 6 shows a block configuration of an information processing apparatus according to the third embodiment. Referring to FIG. 1, reference numeral 101 denotes a CPU that controls the entire apparatus (system); 102, a ROM that stores a boot program and a BIOS; and 103, a RAM that is used as a work area of the CPU 101. Deployed or secured. Reference numeral 104 denotes a control program corresponding to a series of processing procedures, reference numeral 105 denotes a buffer area used as a temporary storage location of image data when an image is captured or printed, and reference numeral 106 denotes a control program including the control program 104. Is an operating system (OS) that controls the OS.

Reference numeral 107 denotes an image scanner for reading an image, and reference numeral 108 denotes a large-capacity storage device such as a hard disk drive or a magneto-optical disk drive corresponding to the storage device 9 shown in FIG. 1 in the first embodiment. Note that the storage device 108 also stores the OS 106 and the like. Reference numeral 109 denotes a configuration for reading data from a portable storage medium, such as a floppy disk drive. The control program 104 is stored in one of the floppy disk set in the floppy disk drive 109 and the hard disk drive 108.

Reference numeral 110 denotes a VRAM for developing a bitmap image to be displayed on a display screen, and 111 denotes a VRA.
It is a display for displaying the bitmap image developed on M110.

Reference numeral 112 denotes a keyboard for inputting various information, and 113 denotes a pointing device for designating a desired position displayed on the display screen or selecting one of various menus. It is. A printer 114 outputs image data to a recording medium,
Reference numeral 15 denotes an interface for connecting to another host computer via a network or the like.

The operation in the configuration shown in FIG. 6 is almost the same as in the first embodiment. However, the processing executed by the input / output control circuit 7 in the first embodiment is performed by the CPU 10
1 is performed in accordance with the control program 104. That is, the control program 104 is a program for realizing the processing described in the first embodiment, and can be supplied from the outside via the floppy disk drive 109, for example. The compressed image data according to the third embodiment is stored and held in, for example, the hard disk drive 108.

As described above, in the information processing apparatus shown in the third embodiment, the amount of change for each color component constituting the image data is extracted similarly to the first embodiment.
By determining whether the image data is compressed and stored or only the average value is stored based on the result, the image data amount of the invalid color component is minimized, and the storage capacity in the storage device 10 is effectively reduced. Can be used.

<Other Embodiments> Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus including one device (for example, For example, the present invention may be applied to a copying machine, a facsimile machine, and the like.

Another object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instructions of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0059]

As described above, according to the present invention, an excessive amount of color image data composed of a plurality of color components is minimized by minimizing the amount of image data of color components determined to be invalid. This makes it possible to effectively use the memory area without performing complicated data storage.

[0060]

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration of a determination circuit according to the present embodiment.

FIG. 3 is a flowchart illustrating a storage process according to the embodiment.

FIG. 4 is a diagram illustrating an example of a data structure in a storage device according to the present embodiment.

FIG. 5 is a side sectional view of an image processing apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of an information processing apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanner circuit 2 Printer device 7 Input / output control circuit 8 Buffer memory circuit 9 Image conversion circuit 10 Storage device 11 Judgment circuit

Claims (15)

[Claims] An input unit configured to input image data composed of a plurality of color components; a compression unit configured to compress the image data; and a storage unit configured to store the image data compressed by the compression unit. An image processing apparatus, comprising: a determination unit that determines whether or not the image data should be stored in the storage unit for each color component; and a storage mode of the image data in the storage unit according to a determination result by the determination unit An image processing apparatus, comprising: control means for controlling the image processing. 2. The control unit according to claim 1, wherein the image data compressed by the compression unit is determined for the color component determined to be stored by the determination unit, and the color data determined to not be stored is determined for the color component determined not to be stored. 2. The image processing apparatus according to claim 1, wherein control is performed such that an amount of image data smaller than the color component determined to be stored is stored in the storage unit. 3. The image processing apparatus according to claim 2, wherein the determining unit includes an extracting unit configured to extract a feature for each color component included in the image data.
3. The image processing apparatus according to claim 2, wherein it is determined whether the image data should be stored in the storage unit. 4. The image processing apparatus according to claim 3, wherein the extraction unit extracts a change amount of the image data for each color component. 5. The image processing apparatus according to claim 1, wherein the determination unit determines that the image data should be stored for a color component whose change amount of the image data extracted by the extraction unit exceeds a predetermined value. 5. The image processing device according to 4. 6. The image processing apparatus according to claim 4, wherein the determination unit determines that image data should not be stored for a color component whose change amount of the image data extracted by the extraction unit is equal to or less than a predetermined value. The image processing apparatus according to any one of the preceding claims. 7. The determination unit further includes an average value calculation unit that calculates an average value of image data for each color component, and the control unit determines that the color component determined not to be stored in the determination unit. 7. The image processing apparatus according to claim 1, wherein the average value calculated by the average value calculation means is stored in the storage device. 8. An output control means for controlling an output order of the image data stored in the storage means, and an output for outputting the image data on a recording medium in accordance with the output order controlled by the output control means. 8. An image processing apparatus according to claim 7, comprising: 9. The image processing apparatus according to claim 8, wherein the output control unit outputs all pixels uniformly as the average value for the color component whose average value is stored in the storage unit. apparatus. 10. An image processing apparatus according to claim 1, wherein said image data is composed of color components of cyan, magenta, yellow, and black. 11. An inputting step of inputting image data composed of a plurality of color components, a determining step of determining whether or not the image data is to be stored in a storage unit for each color component, and storing in the determining step. A compression step of compressing the image data of the color component determined to be required; and the image data of the color component determined not to be stored in the determination step, the color determined to be stored. And a storage step of storing the image data compressed in the compression step and the image data converted in the conversion step for each color component. Characteristic image processing method. 12. The method according to claim 1, wherein, in the determining step, a feature for each color component constituting the image data is extracted, and it is determined whether or not the image data should be stored according to the feature. 12. The image processing method according to item 11. 13. In the determining step, a change amount of the image data is extracted for each color component, and it is determined that image data should be stored for a color component whose change amount exceeds a predetermined value. The image processing method according to claim 12, wherein: 14. The image processing apparatus according to claim 1, wherein in the converting step, the image data is converted into an average value thereof.
2. The image processing device according to 1. 15. A computer-readable memory storing a program code for image processing, wherein a code for an input step of inputting image data composed of a plurality of color components, and whether the image data should be stored in a storage means. A code of a determination step of determining whether or not each color component is not included; a code of a compression step of compressing image data of a color component determined to be stored in the determination step; and a code of a compression step of not storing in the determination step. The image data of the color component determined to be, the code of a conversion step of converting the data amount to be smaller than the color component determined to be stored, the image data compressed in the compression step, A code for a storage step of storing the image data converted in the conversion step for each color component. Memory.