JP2001358954A - Method and device for image processing and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing method by which an image included in a picture can excellently be reproduced. SOLUTION: The image processing method that processes colors by using a color processing condition depending on the distribution of colors when an image type of an object picture indicates an image, has a 1st mode where object pictures of the image existing in a picture are collectively processed and a 2nd mode where different images are independently processed. The method is characterized in that when the 1st mode is set, the color processing condition is set from the color distribution of all the object pictures identified as the image included in the picture and when the 2nd mode is set, the color distribution is obtained from the different images included in the picture and the color processing condition is set to each image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing method, apparatus, and recording medium for performing color processing according to the color distribution of an image.

[0002]

2. Description of the Related Art When an output image based on image data is satisfactorily output by a printer or a display, color correction processing, color conversion processing, It is necessary to perform color processing such as binarization processing. In general, for printing an image created by a computer application and displaying the image on a display, a device driver or a device converts a drawing instruction group from the application into an image of the drawing instruction, creates image data of the entire page, and performs printing and display.

A group of drawing commands constituting a document is issued to a device driver, for example, an image drawing command for a photographic image portion, a text drawing command for a text portion, and a graphics drawing command for a graphics portion. Color processing suitable for the object is performed for each type, and the object is converted into an image that can be output by an output device.

At this time, the color matching processing is switched to "color processing giving priority to vividness" for the graphics part, "colorimetric matching" for the text part, and "color processing giving priority to tint" for the photograph part. Good output can be obtained for all objects on the entire page.

In recent years, depending on the system or application, a "source color space" is specified for these objects, and a device driver can obtain higher quality output using the specified contents. ing. For example, when a scanner input image is pasted on a document, when a color profile describing the device characteristics of the scanner is specified in an image drawing instruction of the image, or when color calibration or the like is performed on a display, an editor A color profile describing the characteristics of the monitor used to reproduce the apparent color of the monitor can be specified. These color profiles are, for example, ICC profiles. As a system that can use these color profiles, Microsoft Corporation Wind
ows ICM, Apple Inc.'s ColorSync and the like are known.

[0006]

However, even with such a detailed color matching processing system, if the original image itself is inferior in a photographic image, it is naturally beautiful and high quality. No output can be obtained. For example, if the exposure of an image taken by a digital camera that has become widespread in recent years is also inappropriate, in the conventional system, the image of the inappropriate exposure is faithfully printed in an inappropriate state, and is not necessarily good. I was dissatisfied that it was not output. To improve this, the user has performed image correction processing such as non-linear color balance processing for correcting the exposure of the original image on the entire original image using image retouching software or the like.

However, a user who does not have a high level of knowledge and experience has to repeat trial and error to set an appropriate correction process, which takes a very long time.

In addition, a DTP in which a photograph that has not been subjected to correction processing and is pasted in document data that already exists is pasted.
If you want to perform image correction only on the photographic part of the original image for something like a document, specify the image part from the original image, perform image correction processing with cut image retouching software, and It was necessary to perform the complicated work of pasting it on a computer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to perform color processing suitable for the type of an object image included in an input image.

In particular, it is an object of the present invention to improve the reproducibility of an image included in an input image.

[0011]

In order to achieve the above object, the present invention comprises the steps of: inputting a drawing instruction indicating an object image forming an image; identifying an image type of the object image based on the drawing instruction; If the image type is an image, color processing conditions are set according to the color distribution of the object image, and color processing is performed on the object image identified as the image using the set color processing conditions. An image processing method, comprising: a first mode in which object images of an image existing in an image are collectively processed; and a second mode in which different images are independently processed. Is set, the color processing condition is set from the color distribution of all object images identified as images contained in the image, and the second If the mode is set, it obtains a color distribution for different image contained in the image, and sets the color processing condition for each said image.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic example of a system according to the present embodiment.

The host computer 100 includes a printer 105 such as an ink jet printer and a monitor 1.
06 is connected. The host computer 100
Application software 101 such as a word processor, spreadsheet, Internet browser, etc., and various drawing commands (image drawing command, text drawing command, graphics drawing command) indicating an output image issued by the application to the OS 102 are received from the OS and processed. The software includes a printer driver 103 for creating print data, a monitor driver 104 for processing various drawing commands issued by the application and displaying the same on a monitor 106, and a color matching module 111 for performing a color matching process in response to an application request. .

The host computer 100 includes a central processing unit CPU 108 and a hard disk driver HD1 as various hardware on which the software can operate.
07, a random access memory RAM 109, a read only memory ROM, and the like.

As an embodiment shown in FIG. 1, for example, a Windows 9 of Microsoft Corporation is installed in a personal computer of an IBM AT compatible machine which is widely used.
5 is used as an OS (Operating System), an arbitrary printable application is installed, and a monitor and a printer are connected.

In the host computer 100, text data classified into text such as characters, graphics data classified into graphics such as figures, natural images, etc. are displayed by the application 101 based on a display image in response to a user instruction. Output image data is created by using image image data classified as. When printing out the output image data, the application 101 issues a print output request to the OS 102,
The graphics data part is a graphics drawing instruction,
The image image data portion issues a drawing command group indicating an output image composed of an image drawing command. The OS 102 receives the output request and issues a drawing command group to the printer driver 103 corresponding to the output printer. The printer driver 103 processes the input drawing command group, creates print data printable by the printer 105, and transfers the print data to the printer 105. When the printer 105 is a raster printer, the printer driver 103 sequentially rasterizes the drawing commands from the OS into the RGB 24-bit page memory, rasterizes all the drawing commands, and then converts the drawing commands to RGB.
The contents of the 24-bit page memory are converted into a data format printable by the printer 105, for example, CMYK data, and transferred to the printer.

Next, a printing process performed by the printer driver 103 will be described.

The printing process performed by the printer driver 103 is roughly classified into the following five processes.

1. Identification Processing By determining the type of an object image drawing command input from the OS 102, it is determined whether the object indicated by the drawing command is a photographic image portion, a text portion, or a graphics portion.

2. Image Correction Processing The image correction processing corrects the color balance that has been lost due to the influence of shooting conditions and the like. A luminance histogram is created for the photographic image, and a nonlinear color balance correction condition is obtained.
Then, the color balance, contrast, and saturation of the photographic image are satisfactorily corrected by performing nonlinear color balance correction on the photographic image.

3. Color matching processing This processing is performed by the color matching module 111 using a source profile corresponding to the input color information included in the drawing command and a printer profile corresponding to the printer, and converts the input color information into printer color information dependent on the printer. Convert.

When a profile is added to the header part of the function of the drawing command, the added profile is used as the source profile. If no profile is added, the host computer 100
Or a profile corresponding to the setting by the printer driver is used.

The color gamut of a printer is narrower than the color gamut of a monitor. Therefore, the color indicated by the input color information may not be able to be faithfully reproduced by the printer. Therefore,
In the color matching processing, the input color information is converted into printer color information indicating colors within the color reproduction range of the printer by using a color matching processing method corresponding to the type of image indicated by the input color information. This conversion is realized by performing a color matching process using a printer profile.

4. Rasterization processing Based on color information on which image correction processing and color matching processing have been performed, R
GB raster data is generated and sequentially rasterized in an RGB 24-bit page memory.

[5] Printer color processing Brightness / density conversion processing, masking processing, gamma processing, N-value processing (quantization processing) for RGB raster data
Is performed, and C corresponding to the recording material CMYK used in the printer is used.
Convert to MYK data.

FIGS. 2 and 3 show an example of a user interface for designating the setting of color processing conditions for an image in a page. FIG. 2 is a diagram illustrating an example of an instruction for setting independent color processing conditions for each drawing command corresponding to an object image of an image included in the same page (photo data correction items on a user interface). FIG. 3
Is an example of an instruction for setting the same color processing condition for an object image of an image included in the same page (setting a collective item in a page on the user interface to an effective state).

The process flow of the printer driver when the in-page batch item is set will be described below with reference to FIGS. 4 and 5.

The printer driver requests the application or the OS twice for print data (drawing command group) constituting the print page image. In response to the first and second requests, the application issues all drawing command group sets necessary to output a page.

FIG. 4 shows the first print data processing flow, and FIG. 5 shows the second print data processing flow.

In the first print data processing flow, print data is analyzed to collect information necessary for image correction processing, and preparations for execution of image correction processing are made. In the second print data processing flow, image correction processing is performed only on a portion of the image drawing command determined to require image correction processing, using the prepared result of the image correction processing execution prepared earlier, and color matching is performed. The processing is performed, the drawing command is rasterized in the page memory, a print image is created, and the print image is transferred to the printer.

The first print data processing flow shown in FIG. 4 will be described.

In step S10, drawing commands are received one by one from the application or the OS. In step S20, the contents of the drawing command are analyzed, and the type of the object image indicated by the drawing command is identified. If the drawing command is different from the image drawing command such as text or graphics, it is determined that the type of the object image is not a photograph, and the process proceeds to S30, and then proceeds to S80.

In S20, if the print data is an image drawing command, the flow advances to S40. The image correction process used in the present embodiment is a process for correcting a color balance that has been destroyed due to the influence of shooting conditions and the like. Therefore, the target is a photographic image in which color gradation is regarded as important. In general, photographic images are often 24-bit RGB object images, and have a smaller bit depth (for example,
In many cases, the original image is not a photograph, and the image image of the (8-bit palette) is not appropriate as a correction processing target. For this reason, in S50, the process refers to the header of the function of the image drawing command, and proceeds to S60 only when the bit depth of the image is 24 bits or more.

Next, in S60, the contents of the object image passed by the image drawing command are sampled. In the correction logic used in the present embodiment, it is sufficient to obtain an outline of the luminance histogram of the object image. Therefore, when the object image has a certain size or more, it is not necessary to sample all the pixels. The quality of the result does not change even if sampling is performed while thinning is performed. Therefore, in S60, the processing speed is increased by determining the sampling thinning rate based on the size of the object image and performing the thinning sampling.

For example, if the size of the object image is 100
If it is x100 pixels, a luminance histogram is created by sampling all pixels. If it is 200x200 pixels, processing is performed every other line, and sampling is performed every other line in each processing line.

For example, when the width of the object image is W, the height is H, and the vertical and horizontal thinning rates are SkipX and SkipY, the method is as follows: SkipX = (W / 100) +1 SkipY = (H / 100) +1 Can obtain the thinning rate.

The method of obtaining the thinning rate is not limited to this, and a value suitable for the correction logic to be used may be applied.

Next, in S70, the result of the sampling process created in S60 and the drawing command information included in the image drawing command are stored in the hard disk or RAM.
Etc. to a temporary storage device.

In step S80, steps S10 to S8 are performed until the above-described processing is completed for all drawing commands in the page.
The processing up to 0 is repeated, and when the processing of all the print data is completed, the process proceeds to S90.

Next, in S90, the correction parameters used in the above-described image correction processing are calculated from the luminance histograms for all the images in the page, and the calculation results are stored in the temporary storage device.

The correction parameters are described in, for example, Japanese Patent Application No. 10-1.
As described in No. 77272, a highlight point and a shadow point in all images obtained from the luminance histogram are obtained, and are calculated based on the highlight point and the shadow point.

With the above, the first print data processing flow shown in FIG. 4 is completed, and the printer driver requests the OS or the application to transmit the second print data.

FIG. 5 shows the second print data processing flow.

As in the first print data processing flow, S
At step 200, print data (drawing command) is received one by one from the application or the OS. At step S210, the contents of the drawing command are analyzed. If the drawing command is not an image drawing command such as text or graphics, the process proceeds to S220 and S260. A color matching process according to the type of the advanced object is performed, and rasterization is performed on the page memory in S270.

In the case of an image drawing command in S210, the process proceeds to S230.

In S240, it is determined from the information stored in the temporary storage in S90 whether or not a correction process for the image drawing command in the current page is necessary. If it is determined in step S240 that the correction process is not necessary, the process proceeds to step S260, where the color matching process is performed.
At 70, rasterization is performed on the page memory.

If it is determined in S240 that the correction process is necessary, the process proceeds to S250. In step S250, an image correction process is performed on the object image requested to be drawn by the image drawing command using the information stored in the temporary storage device in step S90.

In step S250, the object image that has been subjected to the correction processing is subjected to color matching processing of "color priority" which is a color matching processing corresponding to a photograph in step S260, and rasterized in a page memory in step S270.

In step S280, it is determined whether or not processing of all print data in the page has been completed.
The processing of 0-S280 is repeated.

If it is determined in step S280 that the processing of all print data in the page has been completed, the process proceeds to step S280.
In step 290, the printer performs color processing for the print image data created in the page memory, and converts the print image data into an image that can be output by the printer.

In step S300, the print image converted into an image that can be output by the printer is processed into print data that can be processed by the printer and transferred. Normally, a raster printer compresses data for each raster line and packs it into a simple printer command for transfer.

According to the present embodiment, it is possible to perform image correction processing on an image included in an input image according to a color distribution.

Further, by processing the images existing in one page at a time, the same correction processing can be performed on all of the divided images by the application.

Next, as shown in FIG. 2, a description will be given of the flow of processing of the printer driver when the in-page batch item is not set. Steps for performing the same processing as in FIGS. 4 and 5 will not be described.

In the first print data processing flow, the brightness histogram created in S70 of FIG. 4 is managed independently for each object. Then, in S90, a correction parameter is created independently for each object.

In the second print data processing flow, in S250 of FIG. 5, the correction processing is performed using the correction parameters created in S90 corresponding to the object to be corrected.

(Modification) In the above embodiment, the print request is issued twice to the application. However, the drawing command input in the first print request is stored so that the second print request is not required. It does not matter.

Further, in the above-described embodiment, the mode in which the image correction processing is performed in the printer driver has been described. However, the present invention can naturally be performed by the monitor driver. Moreover,
The image correction processing can be performed by a color correction application.

Although the above embodiment has been described using a raster driver as a printer driver, the present invention can also be applied to a printer driver compatible with a page description language such as post-crypt.

In addition to manually instructing whether or not to perform the image correction processing on the user interface of the printer driver, the correction processing may be performed according to a drawing command in a page.

The correction parameter is not a luminance histogram, but a highlight point and a shadow point may be obtained and calculated from, for example, a hiss and a gram of each of the RGB color components. Also, it may be calculated from other values such as an average value and an intermediate value instead of the highlight point and the shadow point.

When there is a function for determining whether or not the object images of the images in the image are originally the same image, if the in-page batch item is not set, this function is used for the same page. May be grouped, and a correction parameter may be set for each grouping. As a function of determining, for example, a function of determining whether the vertical and horizontal dimensions of the object image of each image are the same, and determining the same image if they are the same can be considered.

The present invention can be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.) or to an apparatus composed of one device (for example, a copying machine or a facsimile machine). May be.

Further, in order to realize the functions of the above-described embodiment, software for realizing the functions of the above-described embodiment is installed in an apparatus or a computer in a system connected to the various devices so as to operate the various devices. The present invention also includes programs executed by supplying the above-described program code and operating the various devices according to a program stored in a computer (CPU or MPU) of the system or apparatus.

In this case, the software program code itself implements the functions of the above-described embodiment, and the program code itself and means for supplying the program code to a computer, for example, the program code The stored storage medium constitutes the present invention.

As a storage medium for storing the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-R
An OM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the supplied program code, not only the functions of the above-described embodiment are realized, but also the program code can be executed by an OS running on the computer or other application software. It goes without saying that such a program code is also included in the embodiment of the present invention when the functions of the above-described embodiment are implemented jointly.

Further, the supplied program code is stored in a memory provided in a function expansion board of the computer or a function expansion unit connected to the computer, and then stored in the function expansion board or the function storage unit based on the instruction of the program code. It is needless to say that the present invention includes a case where a provided CPU or the like performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0069]

According to the present invention, an object image of an image included in an image can be reproduced well.

For example, even if the same image image is complicatedly divided by an application, it can be reproduced well by using a mode in which object images of images existing in the image are collectively processed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a system configuration to which the present invention is applied.

FIG. 2 is a view showing a user interface in a case where it is specified that correction processing is individually performed on an image in a page.

FIG. 3 is a view showing a user interface in a case where it is specified that correction processing is performed on all images in a page at once.

FIG. 4 is a flowchart illustrating a first print data processing flow;

FIG. 5 is a flowchart illustrating a second print data processing flow.

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Claims (8)

[Claims] 1. A drawing instruction indicating an object image constituting an image is input, and an image type of the object image is identified based on the drawing instruction. If the image type is an image, a color distribution of the object image is determined. An image processing method for setting a color processing condition according to the following, and performing color processing on the object image identified as the image using the set color processing condition, wherein the object image of the image existing in the image is provided. And a second mode for processing different images independently. When the first mode is set, an image included in the image is provided. Setting the color processing condition from the color distribution of all object images identified as, and if the second mode is set, it is included in the image Consisting calculated color distribution for each image, an image processing method characterized by setting the color processing condition for each said image. 2. The image processing method according to claim 1, wherein the color distribution is a luminance histogram. 3. The image processing method according to claim 2, wherein a color matching process according to the image type is performed on the color-processed image signal. 4. The image processing method according to claim 1, wherein the color distribution is obtained according to an image signal sampled under a sampling condition corresponding to a size of the object image. 5. The image processing apparatus according to claim 1, wherein the object image of the image is an object image represented in a bitmap format, and is an image whose gradation is important.
The image processing method described in the above. 6. An input unit for inputting a drawing command indicating an object image forming an image, an identification unit for identifying an image type of the object image based on the drawing command, and when the image type is an image, A color processing unit that sets color processing conditions according to the color distribution of the object image and performs color processing on the object image identified as the image using the set color processing conditions. A first mode for collectively processing object images of images existing in an image, and a second mode for independently processing different images, wherein the first mode is set. The color processing conditions are set from the color distributions of all object images identified as images included in the image, If de is set, obtains a color distribution for different image contained in the image, the image processing apparatus characterized by setting the color processing condition for each said image. 7. The image processing apparatus according to claim 6, further comprising image forming means for forming an image on a recording medium based on the color-processed image signal. 8. A recording medium on which a computer-readable program is recorded, wherein the program inputs a drawing command indicating an object image forming an image, and the image of the object image is input based on the drawing command. When the image type is an image, a color processing condition is set according to a color distribution of the object image, and the set color processing condition is set for the object image identified as the image. A program for realizing an image processing method of performing color processing using the image processing method, by setting the color processing condition from the color distribution of all object images identified as images included in the image, A first mode in which object images of images existing in the image are collectively processed; A program for realizing a second mode for independently processing different images by obtaining a color distribution for each different image included and setting the color processing conditions for each image is recorded. Recording medium characterized by the above-mentioned.