JP2006015514A - Image processing method and image processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform color reproduction suiting a user's personal taste when a photographic image is printed and outputted by index printing a plurality of images different in colors (brightness, hue, chroma and the like) to an object displayed on the user's monitor by using a plurality of objects (a person's face, sky, green, flowers and the like). <P>SOLUTION: The image processing method sets an image processing table or parameters for one object or one scene by treating that by a plurality of different image processing and printing and selecting one optional one. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing method and an image processing apparatus, and is capable of printing out image data such as digital photographs in a color desired by each user.

  In recent years, with the development of ink-jet printing technology, it has become possible to print out images taken with a high-pixel digital camera better than before.

  However, when a digitized photo image is printed out by a printer, the output image is not always printed in a color preferred by the user. In particular, blue, green, skin color, and the like are called memory colors, and are colors that greatly divide user preferences. In other words, if the memory color is slightly shifted, the impression of the image often changes greatly.

  For example, even in a blue sky color in a photograph, a bright cyan blue color is preferred, and a deep magenta blue color is preferred. In addition, regarding the skin color, the skin color preferred by the user may differ depending on the country, region, generation, and subject. That is, with only one color look-up table and color function parameters, only one color can be printed out, and it is difficult to express colors desired by all users with a printer.

  Recently, photo images are often taken into a personal computer and edited while looking at a monitor. You can also view images taken with a digital camera connected to a TV. However, when printing such an image, it is very difficult to adjust the color displayed on the monitor to match the color of the printed material, and it is difficult to reproduce the color desired by the user.

  This is because the color seen by each user varies greatly depending on the type of monitor and the display setting value, and such a difference is an adverse effect on the individual user's favorite color reproduction.

  Furthermore, there are cases where it is desired to match the print color with the color of a photograph as a model. In this case, it is necessary to adjust the sample sample and the print sample to the same color under the same light source. On the other hand, there are cases where it is necessary to output a certain color such as a color mark for business use. In this case as well, for example, the print sample of the color patch and the color target must be adjusted to the same color under the same light source.

  In such a problem, in Patent Document 1, the user instructs to convert an arbitrary color to another designated color, and performs color conversion processing such as hue division masking processing on the input image signal based on the designation information. Propose that.

However, in the method as disclosed in Patent Document 1, there is a possibility that even if an arbitrary color is designated as another color, a color in the vicinity thereof is not converted into a desired color.
JP-A-11-298745

  For this reason, the present invention is characterized in that an image processing table or parameters are set by printing a plurality of different image processes on one object or scene and selecting any one of them. To do.

  The plurality of different images to be printed are images obtained by changing any or all of a signal representing brightness of the object or scene, a signal representing color, and a signal representing vividness.

  The image processing is repeated a plurality of times for a plurality of different objects or scenes of the same system color, and an image processing table or parameters are set by a learning function.

  The image processing is performed on each of a plurality of different objects or scenes of other system colors.

  The signal representing brightness is luminance or lightness, the signal representing color is hue, and the signal representing vividness is saturation.

  In this embodiment, a signal representing brightness is treated as luminance, but it is obvious that brightness may be used.

  The present invention uses a plurality of objects (person's face, sky, green, flowers, etc.) and a plurality of images having different colors (lightness, hue, saturation, etc.) with respect to the objects displayed on the user's monitor. It is an object of the present invention to provide an image processing method and an image processing apparatus that perform index printing, and a user selects one of them, and reproduces a user's personal favorite color when outputting a photographic image or the like. .

  For example, an image of a scene having an object such as a human face, a green plant, a blue sky, or such a scene is prepared, and an image whose hue, saturation, and luminance are changed is index-printed. The image prepared here may be stored in advance in the application 101 or the printer driver 103, or may be set to use an original image taken by the user. The user can compare multiple images that have been index printed, compare them with the images displayed on their monitor, or compare them with a model photo or color standard to find an image with the best color for each object or scene. Select one.

  At this time, for example, if a color lookup table or color processing parameters are set in the selection result of only one person image, a sufficiently good image is not always obtained for other person images. Initially, if the reddish skin color is set to yellow, the originally yellowish image may have a further yellowish skin color in that setting. Therefore, in order to obtain a good color for the user in various skin color images, it is necessary to perform color selection processing a plurality of times using various skin color images and set a color lookup table and color processing parameters.

  So, for example, using an image with a flesh-colored object, you can index print multiple images with either or all of brightness, hue, and saturation, select one of them, and select a color lookup table or color Set processing parameters. This selection process is repeated by using different images of the same system color, that is, images having skin-colored objects different from the images. Each time, the learning function changes the color look-up table or color processing parameters, and sets the user's most preferable color each time selection processing is performed. By doing so, it is possible to print in a preferable color without exception in any image.

  The user's favorite color can be selected by looking at the color of the printed sample and selecting the most suitable color for the image, or the color closest to the user's television or monitor. . Alternatively, the closest color may be selected by comparing with a model photograph or color mark.

  An object of the present invention is to provide an image processing method and an image processing apparatus capable of printing out image data such as a digital photograph in a color desired by each user.

  In more detail, the present invention can solve the above problems by the following configuration.

  (1) An image characterized by printing a plurality of different image processes on one object or scene, and setting an image processing table or parameters by selecting any one of them. Processing method.

  (2) The plurality of different images to be printed are images obtained by changing any or all of a signal representing brightness of the object or scene, a signal representing color, and a signal representing vividness. The image processing method according to (1).

  (3) The signal representing brightness is luminance or lightness, the signal representing hue is hue, and the signal representing vividness is saturation, The image processing method according to 2).

  (4) The image processing method is characterized in that the image processing is repeated a plurality of times for a plurality of different objects or scenes of the same system color, and an image processing table or parameter is set by a learning function.

  (5) The image processing method according to (1), wherein the image processing is performed on a plurality of different objects or scenes of other colors.

  (6) An image in which an image processing table or parameters are set by printing a plurality of different image processes on one object or scene and selecting any one of them. Processing equipment.

  (7) The plurality of different images to be printed are images obtained by changing any or all of a signal representing brightness of the object or scene, a signal representing color, and a signal representing vividness. The image processing apparatus according to (6).

  (8) The signal representing brightness is luminance or lightness, the signal representing color is hue, and the signal representing vividness is saturation, The image processing apparatus according to 7).

  (9) The image processing according to (6), wherein the image processing is repeated a plurality of times for a plurality of different objects or scenes of the same system color, and an image processing table or parameters are set by a learning function. apparatus.

  (10) The image processing apparatus according to (6), wherein the image processing is performed on a plurality of different objects or scenes of other colors.

  According to the present invention, a user's favorite color is set by selecting one of a plurality of index-printed images as an important color for a photograph called a memory color. At this time, by performing selection processing using a plurality of different images of the same system color using the learning function, it is possible to output a user's favorite color in various images.

  As a result, a printer that has been able to have only one type of color space so far can print colors preferred by each user.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 1 is a block diagram showing a schematic configuration of a printing system according to an embodiment of the present invention. This system generally includes a host computer 100, a printer 106, and a monitor 105. That is, for example, an inkjet printer 106 and a monitor 105 are connected to the host computer 100 so as to be capable of bidirectional communication.

  The host computer 100 has an OS (Operating System) 102, and is issued by an application 101 such as a word processor, spreadsheet, image processing, and Internet browser that performs respective processing under the management of the OS 100. Processes various drawing command groups (image drawing commands, text drawing commands, graphics drawing commands) indicating output images to generate print data, and similarly processes various drawing command groups issued by the application 101. The monitor driver 104 for displaying on the monitor 105 is provided as similar software.

  The host computer 100 also includes a central processing unit CPU 108, a hard disk driver HD 107, a random access memory (RAM) 109, a read only memory (ROM) 110, and the like as various hardware that can be operated by the above-described software. That is, the CPU 108 executes signal processing for processing according to the above-described software, and the hard disk and the ROM 110 that are driven by the hard disk driver 107 store these various software in advance, and read them out as necessary. To be used. The RAM 109 is used as a work area for executing signal processing by the CPU 108.

  As an embodiment shown in FIG. 1, for example, a Windows (registered trademark) XP of Microsoft Corporation is used as an OS for a personal computer of an AT compatible machine of IBM, which is widely used, and arbitrary printing processing is possible. For example, you can install an application and connect a monitor and a printer.

  In the print system having the above-described configuration, the user can also perform graphic data such as text data and graphics that are classified into text such as characters based on the display image displayed on the monitor 105 by the application 101 and similarly through processing by the application. It is possible to create image data including graphics data classified into a class, image image data classified into a natural image, and the like.

  When the user instructs the print output of the created image data, the application 101 makes a print output request to the OS 102, and configures the graphics data portion as a graphics drawing command and the image image data portion as an image drawing command. The drawing command group indicating the output image is issued to the OS 102. In response to this, the OS 102 receives an application print output request and issues a drawing command group to the printer driver 103 corresponding to the printer that performs the printing.

  The printer driver 103 processes the print request and drawing command group input from the OS 102, creates print data in a form that can be printed by the printer 106, and transfers the print data to the printer 106. In this case, when the printer 106 is a raster printer, the printer driver 103 sequentially performs image correction processing on the rendering command from the OS 102 and sequentially rasterizes it into the RGB 24-bit page memory, and rasterizes all the rendering commands. After that, the contents of the RGB 24-bit page memory are converted into a data format printable by the printer 106, for example, CMYK data, and transferred to the printer.

  FIG. 2 is a diagram illustrating processing performed by the printer driver 103. The processing of the printer driver 103 is roughly divided into image correction processing and printer correction processing.

  The image correction process 120 performs an image correction process on the color information including the luminance signals R, G, and B included in the drawing command group input from the OS 102. Specifically, automatic gradation correction processing described later is performed based on the color information of red (R), green (G), and blue (B). On the other hand, the printer correction processing unit 121 first rasterizes the color information drawing command corrected by the image correction processing 120 and generates a raster image in an R, G, B 24-bit page memory. Then, cyan (C), magenta (M), yellow (Y), and black (K) data depending on the color reproducibility of the printer that performs printing for each predetermined pixel is generated and transferred to the printer 106.

  Next, a color selection function that is a process of the image correction process 120 will be described.

  The present invention prints a plurality of images in which the brightness, saturation, and hue of a specific color in an image are changed, and selects one to be considered as a user's preference from among the images. Provided is a method and an apparatus that can set a color conversion table or parameters based on the results and print an optimum color for the user.

  Image data is usually represented by RGB data. Each color has 1 BYTE, that is, 256 gradations, and a color is expressed by a combination of three colors. However, when this RGB data is used, there is an aspect in which it is difficult for the user to intuitively understand the degree and change of color. Therefore, if the RGB data of the three primary colors are handled with three-dimensional polar coordinates such as luminance (Y), saturation (S), and hue (H), it becomes very easy to understand. Here, how to convert RGB data to YSH data will be described.

First, RGB data is converted into a luminance value (Y) representing brightness and color difference values (Cb) and (Cr) representing color. The conversion formula is
Y = 0.299 * R + 0.587 * G + 0.114 * B
Cb = BY
Cr = R−Y
It is represented by

となる。 Further, from the YCbCr data, the equations for obtaining the saturation (S) and the hue (H) are as follows:

It becomes.

  Image processing is performed based on the luminance (Y), saturation (S), and hue (H) thus obtained. This series of data conversion is shown in FIG. It is also clear that RGB data can be obtained again by back-calculating the above calculation from YSH data.

  First, FIG. 4 shows a human face photograph as a first object. Centered on the original image (E in FIG. 4), an image (D in FIG. 4) in which only the flesh color hue (H) is increased and the flesh color is rotated in the yellow direction, and only the flesh color hue (H) is obtained. An image obtained by lowering and rotating the skin color in the red direction (F in FIG. 4), and an image in which the brightness (Y) value of the skin color region is increased in each image (DF in FIG. 4) (AC in FIG. 4) ), Which have been subjected to a total of six types of image processing, are prepared and displayed on a monitor.

  For example, the hue (H) is converted to ± 10 ° for the hue (H) and +20 for the luminance (Y).

  The person images on which the above six kinds of skin colors are drawn are arranged in parallel on one or a plurality of sheets for index printing. The user compares a plurality of printed images and selects one of the images A to F that he considers most preferable. The selection result is input on the screen (FIG. 4) displayed on the monitor 105. As shown in FIG. 4, a check box may be provided, and a selection image may be checked, or a selection symbol may be directly input to the designation field using a keyboard. In FIG. 4, the selection process is performed by checking image A.

  In this way, when an image having one object is used and the user's preference is set for colors such as skin color and green, those results are transferred to the image correction processing 120. Here, parameters for locally moving a color space represented by RGB data or YCbCr data according to the selection result, or for performing function processing on input RGB data are determined. In the present invention, a method for setting a color lookup table for locally moving the color space will be described.

  From the selection result, a skin color luminance change amount, a hue change amount, and a saturation change amount are obtained. In FIG. 4, the luminance change amount +20, the hue change amount −10, and the saturation change amount 0 from the above. Based on these, only the skin color area in the YCbCr space is moved locally and smoothly to the desired color area.

  First, a specific point that is the center of the skin color region is moved in a plane within the color difference value CbCr plane based on the hue change amount and the saturation change amount, and then the luminance value (Y) is converted from the luminance change amount, and the specific point is preferable. Move to the set skin color. Along with this, by moving the skin color area around the specific point with an inclination distribution, the skin color area other than the specific point is also moved in the preferred direction, and other areas that are not the skin color are not moved. To do.

  Alternatively, the luminance may be converted first, and then the skin color region may be moved in the order of hue and saturation. The means for moving the skin color region in a preferred direction may be made variable in the image or the processing system.

  Thus, the Y'Cb'Cr 'color space can be obtained by locally moving the YCbCr color space.

  A series of operations are performed for each color (green, blue, etc.), and the color lookup table is set by moving the YCbCr space locally for each object.

  Next, FIG. 5 shows a human image having a skin color different from that of FIG. 4 as an object of the same system color. The image used here is an image that has passed through the color lookup table set above. Also in FIG. 5, as in FIG. 4, an image (D in FIG. 5) in which the skin color is rotated in the yellow direction by increasing the value of only the flesh color hue (H) around the original image (E in FIG. 5), the skin color An image obtained by reducing the value of only the hue (H) of the skin and rotating the skin color in the red direction (F in FIG. 5), and an image in which the luminance Y value of the skin color region is increased in each image (DF in FIG. 5) Images having been subjected to a total of six types of image processing (A to C in FIG. 5) are prepared and displayed on a monitor.

  From the selection result of FIG. 5, the color space conversion process is performed again on the color lookup table set in the selection process of FIG. Here, using a learning function using a neural network, the color lookup table is set by performing selection processing a plurality of times with different images of the same system color.

  The same processing is performed for other colors such as green and blue images, and a learning function is used for each color to create one color lookup table that can finally reproduce the user's preferred colors.

  The order of the colors to be set is shown as an example in which the skin color is first performed this time, but the order may be changed depending on the importance and the device. In addition, the selection process may be performed using other colors such as red and yellow, and colors related to the gray axis such as white and black.

  By the way, although the process is performed in the YCbCr color space, for example, the RGB color space can be processed in the L * a * b * color space based on sRGB. In this case, the lightness L * is used instead of the luminance.

  Further, although the process of changing the luminance, hue, and saturation is performed in the YCbCr color space, the process of adding and subtracting the R, G, and B signals independently in the RGB color space may be performed.

  The converted Y'Cb'Cr 'color space data is converted into RGB data to obtain an R'G'B' lookup table. The series of data conversion processes is shown in FIG. The RGB data forming the original image is interpolated with reference to the R′G′B ′ look-up table thus created, and converted image data is created. At this time, the interpolation method may be a generally well-known cubic interpolation method or a tetrahedral interpolation method.

  Further, a method of converting the RGB data of the original image functionally by setting parameters as described above without using a lookup table is also conceivable.

  In this way, the skin color, green, and blue of the original image can be converted into a favorite color set by the user and printed without adversely affecting other colors. As another utility, characteristics unique to a device such as a digital still camera or a monitor used by a user can be absorbed on the printer side by using this processing. This processing flow is shown in FIG.

  The user may compare the printed index image and select one suitable for his / her memory color, or if he wants to match the print color with the monitor color, he / she can display the image on the monitor and You can select one of the prints that matches your monitor. When it is desired to print the same color as the model photo, the model photo and the index print may be compared under the same light source, and one of the index prints may be selected. Furthermore, it may be set so that color patches can be index printed for business use and printed in accordance with various color standards as compared with color targets.

<Other embodiments>
As described above, 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.) but also to an apparatus composed of a single device (for example, a copying machine, a facsimile machine). May be.

  In addition, a program code of software for realizing the functions of the embodiment is provided in an apparatus or a computer in the system connected to the various devices so as to operate the various devices so as to realize the functions of the above-described embodiments. What is implemented by operating the various devices in accordance with a program stored in a computer (CPU or MPU) of the system or apparatus supplied is also included in the scope of the present invention.

  Further, in this case, the program code of the software itself realizes the functions of the above-described embodiments, and the program code itself and means for supplying the program code to the computer, for example, a storage storing the program code The medium constitutes the present invention.

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

  Further, by executing the program code supplied by the computer, not only the functions of the above-described embodiments are realized, but also the OS (operating system) in which the program code is running on the computer, or other application software, etc. It goes without saying that the program code is also included in the embodiment of the present invention even when the functions of the above-described embodiment are realized in cooperation with the embodiment.

  Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, a CPU provided in the function expansion board or function storage unit based on an instruction of the program code However, it is needless to say that the present invention also includes a case where the function of the above-described embodiment is realized by performing part or all of the actual processing.

1 is a block diagram illustrating a configuration of a print system according to an embodiment of the present invention. It is a figure which shows the process of the printer driver in the said system. It is a figure which shows the structure of signal conversion mainly in the brightness | luminance, saturation, and hue process performed as an image correction process among the processes of the said printer driver. It is a figure showing the index screen which selects the skin color in the said system. It is a figure showing the index screen which selects the green in the said system. It is a figure showing the processing flow of the said system.

Explanation of symbols

100 Host computer 101 Application 102 OS (Operating system)
103 Printer Driver 104 Monitor Driver 105 Monitor 106 Printer 107 HD
108 CPU
109 RAM
110 ROM
120 Image correction processing 121 Printer correction processing

Claims (10)

  An image processing method characterized in that an image processing table or parameters are set by printing a plurality of different image processes on one object or scene and selecting any one of them.   The plurality of different images to be printed are images obtained by changing any or all of a signal representing brightness of the object or scene, a signal representing color, and a signal representing vividness. Item 8. The image processing method according to Item 1.   3. The image according to claim 1, wherein the signal representing brightness is luminance or brightness, the signal representing color is hue, and the signal representing vividness is saturation. Processing method.   The image processing method is characterized in that the image processing table or parameter is set by a learning function by repeating a plurality of times for a plurality of different objects or scenes of the same system color.   The image processing method according to claim 1, wherein the image processing is performed on a plurality of different objects or scenes of other system colors.   An image processing apparatus, wherein an image processing table or a parameter is set by printing a plurality of different image processes on one object or scene, and selecting any one of them.   The plurality of different images to be printed are images obtained by changing any or all of a signal representing brightness of the object or scene, a signal representing color, and a signal representing vividness. Item 7. The image processing apparatus according to Item 6.   The image according to claim 6 or 7, wherein the signal representing brightness is luminance or lightness, the signal representing color is hue, and the signal representing vividness is saturation. Processing equipment.   The image processing apparatus according to claim 6, wherein the image processing is repeated a plurality of times for a plurality of different objects or scenes of the same system color, and an image processing table or a parameter is set by a learning function.   The image processing apparatus according to claim 6, wherein the image processing is performed on each of a plurality of different objects or scenes of other system colors.

Images