JP2007241495A - Printer, image processor, printing method, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always print even an image of a person with high picture quality. <P>SOLUTION: A section of the eyes of a person is detected from among image data to be printed, and a grayscale value (white side grayscale value) representing the white section of the eye and a grayscale value (black side grayscale value) representing the black section of the eye are extracted. Then, conversion characteristics are generated so that the white side grayscale value can be converted into a value which is larger than the target value of the white, and that the black side grayscale value can be converted into a value which is smaller than the target value of the black, and the image data of the section of the eye are corrected according to the conversion characteristics. Thus, the white becomes clearly white, and the black becomes clearly black, so that the person can be printed with good impression. Thus, it can be prevented from being misunderstood that the picture quality of the whole image is lower than the actual since the person is not projected with good impression, and it is possible to print the image with high quality where the performance of the printer has been exhibited. Also, a while balance may be set on the basis of the white section of the eye. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for printing an image taken including a person.

  Various household printers such as inkjet printers are widely used as image output devices because they have the advantage of easily printing color images without requiring a large-scale device. . Also, in such a printer, in addition to simply printing, in order to be able to print high-quality images, it is possible to increase the number of ink types used, improve image processing technology, Various types of technologies have been developed, such as making it possible to form multi-sized dots in printers that print dots and print images (for example, Patent Document 1 and Patent Document 2). As a result, it is now possible to print an image taken with a digital camera with a sufficiently high image quality that is comparable to a color photograph printed from a so-called silver salt film.

JP-A-10-175318 Japanese Patent Laid-Open No. 2000-6445

  However, when an image including a person is printed, a satisfactory image may not be obtained even though a sufficiently high-quality image is actually obtained. There was a problem that it might be misunderstood as if it were not.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a technique capable of always printing a sufficiently high-quality image even for an image including a person.

In order to solve at least a part of the problems described above, the first printing apparatus of the present invention employs the following configuration. That is,
A printing apparatus that receives image data of an image taken including at least a person and prints the image,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye part, a white-eye side gradation value representing a gradation value representing a white-eye part and a black-eye side gradation value representing a gradation value representing a black-eye part; ,
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. Conversion characteristic setting means for setting the conversion characteristic of the gradation value to be converted into
Image data correction means for correcting the image data of the eye part according to the set conversion characteristics;
And an image printing means for printing the image based on the corrected image data.

Further, the first printing method of the present invention corresponding to the printing apparatus described above is
A printing method for receiving image data of an image taken including at least a person and printing the image,
A first step of analyzing the image data to detect a portion of the image data in which a human eye is reflected;
A second step of extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing a white-eye part and a black-eye side gradation value that is a gradation value representing a black-eye part;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A third step of setting gradation value conversion characteristics such that
A fourth step of correcting the image data of the eye portion according to the set conversion characteristic;
And a fifth step of printing the image based on the corrected image data.

  In the first printing apparatus and the first printing method of the present invention, when the image data is received, the white-eye portion and the black-eye portion are detected from the portion where the human eye is reflected, and the white-eye portion is detected. A representative tone value (black eye side tone value) and a tone value representative of the black eye portion (black eye side tone value) are extracted. Next, the white-eye side tone value is converted to a value larger than the preset white-eye side target value, and the black-eye side tone value is a value smaller than the preset black-eye side target value. The conversion characteristic of the gradation value that can be converted to is set. Then, after correcting the image data of the eye according to the conversion characteristics, the image is printed based on the obtained image data.

  In this way, when an image showing a person is printed, the face of the person can always be printed with a favorable impression, so that a high-quality image with sufficient performance of the printing apparatus can be printed. It becomes possible. The reason why this is possible will be described supplementarily. If a person appears in the printed image, the viewer's attention tends to be attracted to the face of the person. And if the person's face happens to be in a state that doesn't look good, even if the other parts are printed with sufficient image quality, the impression of the entire image will deteriorate, and the print image quality will not be sufficient. It was found that it was misunderstood like. Furthermore, the impression of a person's face is greatly influenced by the impression of the eyes, and if the white or black eyes are cloudy, the impression of the entire face is deteriorated. On the other hand, it was found that the impression of the entire face was improved when the white eyes were clearly white and the black eyes were clearly black. As is clear from these findings, if the image data is corrected so that the part of the image where the eyes are visible is detected and the white part is printed white and the black part is printed black, Can be printed with a good impression. For this reason, since it is not misunderstood as if the printing image quality is not sufficient, it is possible to obtain a high-quality image in which the performance of the printing apparatus is sufficiently exhibited.

  In the printing apparatus of the present invention, the image data of the eye portion may be corrected as follows. That is, a plurality of white-eye target values for correcting the white-eye color are stored in advance, and one white-eye target value can be selected from these. Then, when the eye portion is detected, the image data of the eye portion may be corrected using the conversion characteristic set using the selected white eye side target value.

  In this way, the white eye color can be corrected to a more preferable color when necessary, so that the performance of the printing apparatus can be sufficiently drawn and a higher quality image can be printed.

Further, in order to solve at least a part of the above-described problems of the conventional technology, the second configuration of the present invention employs the following configuration. That is,
A printing apparatus that receives image data of an image taken including at least a person and prints the image,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye part, a white eye side gradation value which is a gradation value representing the white eye part;
Conversion characteristic setting means for setting the conversion characteristic of the gradation value so that the white-eye side gradation value matches a preset reference white gradation value;
A tone correction unit that corrects the tone of the image data by converting the tone value of the image data according to the set conversion characteristics;
An image printing means for printing the image based on the image data whose color tone has been corrected.

Further, the second printing method of the present invention corresponding to the printing apparatus described above is
A printing method for receiving image data of an image taken including at least a person and printing the image,
A printing method for receiving image data of an image taken including at least a person and printing the image,
Analyzing the image data to detect a portion of the image data in which a human eye is reflected (A);
A step (B) of extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A step (C) of setting a gradation value conversion characteristic so that the white-eye side gradation value matches a preset reference white gradation value;
(D) correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics;
And a step (E) of printing the image based on the image data in which the color tone is corrected.

  In the second printing apparatus and the second printing method of the present invention, printing is performed in a state where the image data of the entire image is corrected so that the white-eye gradation value matches the reference white gradation value. The

  By doing so, not only can the white eye be printed with a preferable color, but a preferable image can be printed by correcting the color tone of the entire image by taking a so-called white balance. At this time, the color tone of the entire image is corrected so that the white of the eye becomes the reference white, and only the white eye portion can be corrected to a color set differently from the reference white. .

Further, in order to print an image by the above-described first printing apparatus or the first printing method of the present invention, the image data is subjected to predetermined image processing to correct the white and black eye colors to preferable colors. If attention is paid to the point that processing is required, the present invention can be grasped as an image processing apparatus and an image processing method as follows. That is, the first image processing apparatus of the present invention is
An image processing apparatus that receives image data of an image captured including at least a person and performs predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion; ,
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. Conversion characteristic setting means for setting the conversion characteristic of the gradation value to be converted into
The present invention includes an image data correction unit that corrects image data of the eye portion according to the set conversion characteristics.

Further, the first image processing method of the present invention corresponding to the above-described image processing apparatus is as follows:
An image processing method for receiving image data of an image captured including at least a person and performing predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected (1);
A step (2) of extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing a white-eye part and a black-eye side gradation value that is a gradation value representing a black-eye part;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A step (3) of setting a conversion characteristic of the gradation value so as to be converted into
And a step (4) of correcting the image data of the eye portion in accordance with the set conversion characteristic.

Furthermore, the second image processing apparatus of the present invention corresponding to the second printing apparatus of the present invention described above is
An image processing apparatus that receives image data of an image captured including at least a person and performs predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye part, a white eye side gradation value which is a gradation value representing the white eye part;
Conversion characteristic setting means for setting the conversion characteristic of the gradation value so that the white-eye side gradation value matches a preset reference white gradation value;
The gist of the present invention is to provide a tone correction means for correcting the tone of the image data by converting the tone value of the image data in accordance with the set conversion characteristics.

The second image processing method of the present invention corresponding to the above image processing apparatus is
An image processing method for receiving image data of an image captured including at least a person and performing predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a human eye is reflected (a);
Extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A step (c) of setting a gradation value conversion characteristic so that the white-eye side gradation value matches a preset reference white gradation value;
And a step (d) of correcting the tone of the image data by converting the gradation value of the image data in accordance with the set conversion characteristics.

  In these image processing apparatuses and image processing methods according to the present invention, when image data is received, a portion in which an image of a person's eyes is detected is detected in the image, and the image data is corrected so that a white eye portion has a preferable color. can do. Therefore, if an image is printed or displayed using the obtained image data, an image showing a person can always be output as a high-quality image.

Furthermore, the present invention can be realized using a computer by causing a computer to read a program for realizing the above-described printing method or image processing method and executing a predetermined function. Therefore, the present invention includes the following program or a mode as a recording medium on which the program is recorded. That is, the program of the present invention corresponding to the first printing method described above is
A program for realizing, using a computer, a method for receiving image data of an image photographed including at least a person and printing the image,
A first function for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A second function of extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A third function for setting the conversion characteristic of the gradation value so as to be converted into
A fourth function for correcting the image data of the eye portion according to the set conversion characteristic;
The main point is to realize the above by a computer.

The recording medium of the present invention corresponding to the above program is
A recording medium which records image data of an image photographed including at least a person and prints the image so as to be readable by a computer,
A first function for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A second function of extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A third function for setting the conversion characteristic of the gradation value so as to be converted into
A fourth function for correcting the image data of the eye portion according to the set conversion characteristic;
The gist is that a program for realizing the above is recorded by a computer.

The program of the present invention corresponding to the second printing method described above is
A program for realizing, using a computer, a method for receiving image data of an image photographed including at least a person and printing the image,
A function (A) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (B) for extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A function (C) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
A function (D) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics;
The gist is to realize a function (E) for printing the image based on the image data whose color tone is corrected by a computer.

The recording medium of the present invention corresponding to the above program is
A recording medium which records image data of an image photographed including at least a person and prints the image so as to be readable by a computer,
A function (A) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (B) for extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A function (C) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
A function (D) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics;
The gist of the invention is that a program for realizing a function (E) for printing the image on the basis of the image data whose color tone is corrected is recorded by a computer.

Furthermore, the program of the present invention corresponding to the first image processing method described above is
A program for realizing, using a computer, a method for receiving image data of an image captured including at least a person and performing predetermined image processing,
A function (1) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (2) for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing the white-eye portion and a black-eye side gradation value that is a gradation value representing the black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A function (3) for setting the conversion characteristic of the gradation value so as to be converted into
The gist of the present invention is that the function (4) for correcting the image data of the eye portion is realized by a computer in accordance with the set conversion characteristics.

The recording medium of the present invention corresponding to the above program is
A recording medium that records image data of an image photographed including at least a person and performs predetermined image processing in a computer-readable manner,
A function (1) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (2) for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A function (3) for setting the conversion characteristic of the gradation value so as to be converted into
The gist of the invention is that a program for realizing the function (4) for correcting the image data of the eye portion by a computer according to the set conversion characteristic is recorded.

The program of the present invention corresponding to the second image processing method described above is
A program for realizing, using a computer, a method for receiving image data of an image captured including at least a person and performing predetermined image processing,
By analyzing the image data, a function (a) for detecting a portion of the image data where a human eye is reflected;
A function (a) for extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing the white-eye part;
A function (c) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
The gist is to realize a function (d) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics.

The recording medium of the present invention corresponding to the above program is
A recording medium that records image data of an image photographed including at least a person and performs predetermined image processing in a computer-readable manner,
By analyzing the image data, a function (a) for detecting a portion of the image data where a human eye is reflected;
A function (a) for extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing the white-eye part;
A function (c) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
The gist of the invention is to record a program for realizing a function (d) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics.

  If these programs are read into a computer and the various functions described above are realized, even an image showing a person can always be printed as a high-quality image.

Hereinafter, in order to clarify the contents of the present invention described above, examples will be described in the following order.
A. Summary of Examples:
B. Device configuration:
B-1. overall structure:
B-2. Internal configuration:
B-2-1. Internal configuration of the scanner unit:
B-2-2. Internal configuration of the printer unit:
C. Image printing process:
D. Eye color correction processing:
E. Variation:
(1) First modification:
(2) Second modification:

A. Summary of Examples:
Prior to detailed description of the embodiment, an outline of the embodiment will be described with reference to FIG. FIG. 1 is an explanatory diagram showing an overview of a printing apparatus 10 according to the present embodiment. The illustrated printing apparatus 10 is provided with a print head 12 that ejects ink droplets, and an image is formed by ejecting ink droplets and forming ink dots while reciprocating the print head 12 on the print medium P. Is a so-called inkjet printer.

  Such inkjet printers have improved in print quality year by year, and nowadays, it is possible to print a sufficiently high-quality image that is comparable to a photo baked from a silver salt film. . However, when printing an image including a person, for some reason, it may not be felt that the image has sufficient print quality. Therefore, as a result of investigating the cause of such a situation, if a person appears in the printed image, the viewer's attention tends to be attracted to the face part of the person. It was found that if the image was taken out of the image, the image quality of the entire image would not be sufficient even if the other parts were printed with sufficient image quality. Furthermore, the impression of a person's face is greatly influenced by the impression of the eyes, and if the white or black eyes are cloudy, the impression of the entire face is deteriorated. On the other hand, it was found that the impression of the entire face is improved when the white eyes are clearly white and the black eyes are clearly black.

  Based on such knowledge, the printing apparatus 10 according to the present embodiment can always print an image with sufficient image quality, as shown in FIG. Modules such as “extraction module”, “conversion characteristic setting module”, and “image data correction module” are mounted. The “module” is a series of processing that is internally performed by the printing apparatus 10 to print an image, focusing on the function. Therefore, the “module” can be realized as a part of the program, or can be realized by using a logic circuit having a specific function, or can be realized by combining them. .

  In the printing apparatus 10 according to the present embodiment, when image data of an image to be printed is received, the following image processing is performed by each module, and then the print head 12 is driven onto the print medium P. Print the image. First, the “eye part detection module” detects a part in which a person's eyes are reflected by analyzing the received image data. Next, the “gradation value extraction module” determines, from the detected eye part, the gradation value representing the white eye part (white eye side gradation value) and the gradation value representing the black eye part (black eye side gradation). Values) are extracted and supplied to the “conversion characteristic setting module”. In the “conversion characteristic setting module”, the target gradation value of the white eye (white eye side target value) and the target gradation value of the black eye (black eye side target value) are preset, and the white eye side gradation value and When the black eye side tone value is received, the following tone value conversion characteristics are set. That is, conversion characteristics are set such that the white-eye side tone value is converted to a value larger than the white-eye side target value, and the black-eye side tone value is converted to a value smaller than the black-eye side target value. The “image data correction module” corrects the image data of the eye according to the conversion characteristics thus set. At this time, the image data of only the eye portion may be corrected, or the image data of the entire image may be corrected. Next, the “image printing module” generates a signal for driving the print head 12 based on the corrected image data, and the image is printed on the print medium P by driving the print head 12. The

  If the image is printed in this way, when printing an image including a person, the white eye portion is clearly white and the black eye portion is clearly black, so the face should be printed with a favorable impression. As a result, any image can be printed with sufficiently high image quality. Below, such a printing apparatus 10 is demonstrated in detail based on an Example.

B. Device configuration :
B-1. overall structure :
FIG. 2 is a perspective view showing the external shape of the printing apparatus 10 according to the present embodiment. As illustrated, the printing apparatus 10 according to the present exemplary embodiment includes a scanner unit 100, a printer unit 200, an operation panel 300 for setting operations of the scanner unit 100 and the printer unit 200, and the like. The scanner unit 100 has a scanner function of reading a printed image and generating image data, and the printer unit 200 has a printer function of receiving image data and printing an image on a print medium. . Further, if an image (original image) read by the scanner unit 100 is output from the printer unit 200, a copy function can be realized. That is, the printing apparatus 10 according to the present embodiment is a so-called scanner / printer / copy combined apparatus (hereinafter referred to as an SPC combined apparatus) that can independently realize a scanner function, a printer function, and a copy function.

  FIG. 3 is an explanatory diagram showing a state in which the document table cover 102 provided on the upper part of the printing apparatus 10 is opened in order to read the document image. As shown in the drawing, when the document table cover 102 is opened upward, a transparent document table glass 104 is provided, and various mechanisms to be described later for realizing the scanner function are mounted therein. . When reading a document image, as shown in the figure, the document table cover 102 is opened, the document image is placed on the document table glass 104, the document table cover 102 is closed, and then the buttons on the operation panel 300 are operated. . In this way, it is possible to immediately convert the document image into image data.

  The scanner unit 100 is entirely housed in an integrated case, and the scanner unit 100 and the printer unit 200 are coupled by a hinge mechanism 204 (see FIG. 4) on the back side of the printing apparatus 10. ing. For this reason, by lifting the front side of the scanner unit 100, it is possible to rotate only the scanner unit 100 at the hinge portion.

  FIG. 4 is a perspective view illustrating a state in which the front side of the scanner unit 100 is lifted and rotated. As shown in the figure, in the printing apparatus 10 of the present embodiment, the upper surface of the printer unit 200 can be exposed by lifting the front side of the scanner unit 100. Inside the printer unit 200, various mechanisms to be described later for realizing the printer function, a control circuit 260 to be described later for controlling the operation of the entire printing apparatus 10 including the scanner unit 100, and the scanner unit 100 are further described. And a power supply circuit (not shown) for supplying power to the printer unit 200 and the like. Also, as shown in FIG. 4, an opening 202 is provided on the upper surface of the printer unit 200, and replacement of consumables such as ink cartridges, paper jam handling, and other minor repairs are performed. Can be performed easily.

B-2. Internal configuration:
FIG. 5 is an explanatory diagram conceptually showing the internal configuration of the printing apparatus 10 of this embodiment. As described above, the printing apparatus 10 includes the scanner unit 100 and the printer unit 200, and various configurations for realizing the scanner function are mounted in the scanner unit 100. Is equipped with various configurations for realizing the printer function. Hereinafter, the internal configuration of the scanner unit 100 will be described first, and then the internal configuration of the printer unit 200 will be described.

B-2-1. Internal configuration of the scanner unit:
The scanner unit 100 includes a transparent platen glass 104 on which a document image is set, a document platen cover 102 for holding the set document image, a reading carriage 110 for reading the set document image, and a reading carriage 110. The driving belt 120 is configured to move in the reading direction (main scanning direction), the driving motor 122 supplies power to the driving belt 120, the guide shaft 106 that guides the movement of the reading carriage 110, and the like. The operations of the drive motor 122 and the reading carriage 110 are controlled by a control circuit 260 described later.

  When the driving motor 122 is rotated under the control of the control circuit 260, the movement is transmitted to the reading carriage 110 via the driving belt 120, and as a result, the reading carriage 110 is guided to the guide shaft 106 while being driven by the driving motor 122. It moves in the reading direction (main scanning direction) according to the rotation angle. Further, the drive belt 120 is constantly adjusted to be in a moderately tensioned state by the idler pulley 124. Therefore, if the drive motor 122 is rotated in the reverse direction, the reading carriage 110 is moved in the reverse direction by a distance corresponding to the rotation angle. It can also be moved.

  Inside the reading carriage 110, a light source 112, a lens 114, a mirror 116, a CCD sensor 118, and the like are mounted. Light from the light source 112 is applied to the platen glass 104 and reflected by a document image set on the platen glass 104. The reflected light is guided to the lens 114 by the mirror 116, collected by the lens 114, and detected by the CCD sensor 118. The CCD sensor 118 includes a linear sensor in which photodiodes that convert light intensity into an electrical signal are arranged in a row in a direction orthogonal to the moving direction (main scanning direction) of the reading carriage 110. Therefore, by moving the reading carriage 110 in the main scanning direction and irradiating the original image with light from the light source 112 and detecting the reflected light intensity by the CCD 118, an electrical signal corresponding to the original image can be obtained.

  Further, the light source 112 is composed of light emitting diodes of three colors of RGB, and can sequentially irradiate light of R color, G color, and B color at a predetermined cycle. In the CCD 118, reflected light of R color, G color, and B color is sequentially detected. In general, the red portion of the image reflects R light, but hardly reflects G or B light, so the R reflected light represents the R component of the image. Similarly, the reflected light of G color represents the G component of the image, and the reflected light of B color represents the B component of the image. Accordingly, if the original image is irradiated while switching the light of three colors of RGB at a predetermined cycle and the reflected light intensity is detected by the CCD 118 in synchronization therewith, the R component, G component and B component of the original image can be detected. It is possible to read a color image. Note that since the reading carriage 110 is moved even while the color of the light emitted by the light source 112 is switched, the position of the image for detecting each component of RGB corresponds to the movement amount of the reading carriage 110 strictly. However, this deviation can be corrected by image processing after reading each component.

B-2-2. Internal configuration of the printer unit:
Next, the internal configuration of the printer unit 200 will be described. The printer unit 200 includes a control circuit 260 that controls the overall operation of the printing apparatus 10, a print carriage 240 that prints an image on a print medium, a mechanism that moves the print carriage 240 in the main scanning direction, and printing. A mechanism for feeding media is mounted.

  The print carriage 240 includes an ink cartridge 242 that stores K ink, an ink cartridge 243 that stores various inks of C ink, M ink, and Y ink, a print head 241 provided on the bottom surface side, and the like. The print head 241 is provided with an ink discharge head for discharging ink droplets for each ink. When the ink cartridges 242 and 243 are mounted on the print carriage 240, each ink in the cartridge is supplied to the ink discharge heads 244 to 247 of each color through an introduction pipe (not shown).

  The mechanism that moves the print carriage 240 in the main scanning direction includes a carriage belt 231 for driving the print carriage 240, a carriage motor 230 that supplies power to the carriage belt 231, and an appropriate tension is constantly applied to the carriage belt 231. And a carriage guide 233 for guiding the movement of the print carriage 240, an origin position sensor 234 for detecting the origin position of the print carriage 240, and the like. When the carriage motor 230 is rotated under the control of the control circuit 260 described later, the print carriage 240 can be moved in the main scanning direction by a distance corresponding to the rotation angle. Further, if the carriage motor 230 is rotated in the reverse direction, the print carriage 240 can be moved in the reverse direction.

  The mechanism for feeding the print medium includes a platen 236 that supports the print medium from the back side, a paper feed motor 235 that feeds the paper by rotating the platen 236, and the like. By rotating the paper feed motor 235 under the control of the control circuit 260 described later, the print medium can be fed in the sub-scanning direction by a distance corresponding to the rotation angle.

  The control circuit 260 has a CPU, a ROM, a RAM, a D / A converter that converts digital data into an analog signal, and a peripheral device interface PIF for exchanging data with peripheral devices. It is composed of The control circuit 260 controls the overall operation of the printing apparatus 10, and controls these operations while exchanging data with the light source 112, the drive motor 122, and the CCD 118 mounted on the scanner unit 100.

  Further, the control circuit 260 drives the carriage motor 230 and the paper feed motor 235 to supply the drive signals to the ink discharge heads 244 to 247 of the respective colors while performing the main scanning and the sub scanning of the printing carriage 240, thereby generating ink droplets. Control to discharge is also performed. The drive signals supplied to the ink ejection heads 244 to 247 are generated by reading image data from the computer 20, the digital camera 30, the external storage device 32, etc., and performing image processing to be described later. Of course, it is also possible to generate a drive signal by performing image processing on the image data read by the scanner unit 100. In this way, under the control of the control circuit 260, the ink droplets are ejected from the ink ejection heads 244 to 247 to form the ink dots of the respective colors on the printing medium while the print carriage 240 is moved in the main scan and the sub scan. It is possible to print an image. Of course, instead of performing image processing in the control circuit 260, the ink ejection heads 244 to 247 receive data on which image processing has been performed from the computer 20, and perform main scanning and sub-scanning of the print carriage 240 according to this data. Can also be driven.

  The control circuit 260 is also connected to the operation panel 300 so as to be able to exchange data. By operating various buttons provided on the operation panel 300, detailed operation modes of the scanner function and the printer function are set. It is possible to set. Further, it is possible to set a detailed operation mode from the computer 20 via the peripheral device interface PIF.

  FIG. 6 is an explanatory diagram showing a state in which a plurality of nozzles Nz for ejecting ink droplets are formed on the ink ejection heads 244 to 247 of each color. As shown in the figure, four sets of nozzle rows for ejecting ink droplets of each color are formed on the bottom surface of the ink ejection head for each color, and 48 nozzles Nz have a nozzle pitch k in one nozzle row. They are arranged in a staggered pattern at intervals. A drive signal is supplied from the control circuit 260 to each of these nozzles Nz, and each nozzle Nz discharges an ink droplet of each ink according to the drive signal.

  As described above, the printer unit 200 of the printing apparatus 10 prints an image by supplying drive signals to the ink discharge nozzles and discharging ink droplets according to the drive signals to form ink dots on the print medium. ing. Control data for driving the ink discharge nozzles is generated by performing predetermined image processing on the image data prior to image printing. Hereinafter, a process (image printing process) of performing image processing on image data to generate control data, and printing an image by forming ink dots based on the obtained control data will be described.

C. Image printing process:
FIG. 7 is a flowchart illustrating a flow of image printing processing performed for printing an image by the printing apparatus 10 according to the present exemplary embodiment. Such a process is a process executed by the control circuit 260 mounted on the printing apparatus 10 using functions such as a built-in CPU, RAM, and ROM. Hereinafter, it demonstrates according to a flowchart.

  When the image printing process is started, the control circuit 260 first reads the image data to be printed (step S100). Here, it is assumed that the image data is RGB image data expressed by gradation values of R, G, and B colors.

  Next, a process of converting the resolution of the read image data into a resolution (printing resolution) for printing by the printer unit 200 is performed (step S102). When the resolution of the read image data is lower than the print resolution, the image data is converted to a higher resolution by performing interpolation calculation between adjacent pixels and setting new image data. Conversely, when the resolution of the read image data is higher than the print resolution, the image data is converted to a lower resolution by thinning out the image data at a certain rate from between adjacent pixels. In the resolution conversion process, the read resolution is converted into the print resolution by generating or thinning out the image data at an appropriate ratio with respect to the read image data.

  When the resolution of the image data is converted to the print resolution in this way, the control circuit 260 starts a process (eye color correction process) for correcting the color of white eyes and black eyes of the image data (step S104). That is, when a person is shown in the image, the face of the person is corrected to a clear white color, and the black eye is corrected to a clean black color so that the face is printed with a favorable impression. As described above, processing for correcting the image data is performed. As described above, in an image showing a person, if the face of the person is not printed with a good impression, the image may be misunderstood as if the image quality is poor. The impression of the face is greatly influenced by the impression of the eyes, and the impression of the face can be greatly improved by correcting the colors of the white and black eyes to the preferred colors. As a result, it is possible to realize that the entire image is printed with sufficiently high image quality. Details of the eye color correction processing will be described later in detail.

  When the eye color correction process is completed, the control circuit 260 of the printing apparatus 10 performs a color conversion process on the corrected image data (step S106). Here, the color conversion process is a process of converting image data expressed in R, G, and B colors into image data expressed by gradation values of C, M, Y, and K colors. The color conversion process is performed by referring to a three-dimensional numerical table called a color conversion table (LUT).

  FIG. 8 is an explanatory diagram conceptually showing a color conversion table (LUT) referred to for color conversion processing. Here, it is assumed that the gradation value of each color of RGB can take a value from 0 to 255. As shown in FIG. 8, considering a color space in which gradation values of R, G, and B colors are taken on three orthogonal axes, all RGB image data are cubes whose length is one side with the origin at the top. It can be associated with a point inside (color solid). This can be thought of as follows if you change your view. That is, when a color solid is subdivided into a grid perpendicular to each axis of RGB and a plurality of grid points are generated in the color space, the coordinate values of each grid point can be read as RGB image data. Therefore, if a combination of C, M, Y, and K gradation values is stored in advance in each grid point, the RGB image data can be converted into each color by reading the gradation value stored in the grid point. It is possible to convert the image data (CMYK image data) represented by the gradation value.

  For example, if the R component of the image data is RA, the G component is GA, and the B component is BA, this image data is associated with point A in the color space (see FIG. 8). Therefore, a cube dV containing point A is detected from small cubes that subdivide the color solid into a lattice shape, and the gradation values of the CMYK colors stored in the lattice points of the cube dV are read out. Then, if the interpolation calculation is performed from the gradation values of these grid points, the gradation value at the point A can be obtained. As described above, the color conversion table LUT is a three-dimensional number in which a combination of gradation values of CMYK colors (CMYK image data) is stored at each grid point indicated by a combination of gradation values of RGB colors. It can be considered as a table, and by referring to the color conversion table, RGB image data can be quickly converted into CMYK image data.

  When the color conversion process is completed as described above, the control circuit 260 starts the halftone process (step S108 in FIG. 7). Halftone processing is the following processing. The CMYK image data obtained by the color conversion process is image data expressed in the range of gradation value 0 to gradation value 255 for each color of C, M, Y, and K. In contrast, since the printer unit 200 prints an image by forming dots, the CMYK image data expressed by 256 gradations is converted into image data (dot data) expressed by the presence / absence of dot formation. Processing is required. Halftone processing is processing for converting image data of CMYK colors into dot data in this way.

  As a method for performing the halftone process, various methods such as an error diffusion method and a dither method can be applied. The error diffusion method is to determine whether or not dots are formed for a certain pixel, so that the error in gradation expression that occurs in that pixel is diffused to the surrounding pixels and the error diffused from the surroundings is eliminated. This is a method of determining the presence or absence of dot formation for each pixel. In the dither method, a threshold value randomly set in the dither matrix and image data of each color of CMYK are compared for each pixel, and it is determined that a dot is formed in a pixel having a larger image data. This is a technique for obtaining dot data for each pixel by determining that a dot is not formed for a larger pixel. As the halftone method, any one of the error diffusion method and the dither method can be used, but the printing apparatus 10 of the present embodiment performs the halftone process using the dither method.

  FIG. 9 is an explanatory diagram illustrating an enlarged part of the dither matrix. In the illustrated matrix, threshold values that are uniformly selected from the range of gradation values 0 to 255 are randomly stored in a total of 4096 pixels, 64 pixels in the vertical and horizontal directions. Here, the threshold gradation value is selected from the range of 0 to 255. In this embodiment, the image data of each color of CMYK after color conversion is 1-byte data, and the gradation value is 0 to 255. It corresponds to the possibility of taking a value. Note that the size of the dither matrix is not limited to 64 pixels in the vertical and horizontal directions as illustrated in FIG. 9, and can be set to various sizes including those having different numbers of vertical and horizontal pixels. It is.

  FIG. 10 is an explanatory diagram conceptually showing a state in which the presence / absence of dot formation is determined for each pixel while referring to the dither matrix. This determination is made for each color of CMYK, but in the following, in order to avoid complicated explanation, image data of each color of CMYK is simply referred to as image data without being distinguished.

  When determining the presence or absence of dot formation, first, the gradation value of the image data for the pixel of interest (the pixel of interest) as the object of determination is compared with the threshold value stored at the corresponding position in the dither matrix. . The thin broken arrow shown in the figure schematically represents that the image data of the pixel of interest is compared with the threshold value stored at the corresponding position in the dither matrix. If the image data of the pixel of interest is larger than the threshold value of the dither matrix, it is determined that a dot is formed for that pixel. On the other hand, when the threshold value of the dither matrix is larger, it is determined that no dot is formed in the pixel. In the example shown in FIG. 10, the image data of the pixel at the upper left corner of the image is “97”, and the threshold value stored at the position corresponding to this pixel on the dither matrix is “1”. Accordingly, for the pixel at the upper left corner, the image data is larger than the threshold value of the dither matrix, and therefore it is determined that a dot is formed on this pixel. An arrow indicated by a solid line in FIG. 10 schematically represents a state in which it is determined that a dot is to be formed in this pixel and the determination result is written in the memory.

  On the other hand, for the pixel on the right side of this pixel, the image data is “97”, and the threshold value of the dither matrix is “177”. Since the threshold value is larger, it is determined that no dot is formed for this pixel. Thus, by comparing the image data with the threshold value set in the dither matrix, it is possible to determine whether or not dots are formed for each pixel. In the halftone process (step S108 in FIG. 7), by applying the above-described dither method to the image data of each color of C, M, Y, and K, the presence or absence of dot formation is determined for each pixel, and the dot data Process to generate.

  As shown in FIG. 7, in the image printing process, when halftone processing is performed to generate dot data for each color of CMYK, interlace processing is started (step S110). The interlace process is a process in which the print head 241 rearranges the dot data in the order in which dots are formed and supplies them to the ink discharge heads 244 to 247 for each color. That is, as shown in FIG. 6, the nozzles Nz provided in the ink discharge heads 244 to 247 are provided with an interval of the nozzle pitch k in the sub-scanning direction. When droplets are ejected, dots are formed at intervals of the nozzle pitch k in the sub-scanning direction. Therefore, in order to form dots in all the pixels, the relative position between the print carriage 240 and the print medium is moved in the sub-scanning direction, and new dots are formed in the pixels between the dots separated by the nozzle pitch k. Necessary. As described above, when an image is actually printed, dots are not formed in order from the upper pixel on the image. Furthermore, for pixels in the same row in the main scanning direction, instead of forming dots in a single main scan, the dots are divided into a plurality of main scans in response to image quality requirements. In this main scanning, dots are also widely formed on the pixels at the skipped positions.

  For these reasons, prior to actually starting dot formation, the dot data obtained for each color of C, M, Y, and K is rearranged in the order in which the ink ejection heads 244 to 247 form dots. Processing is required. Such a process is a process called interlace.

  As shown in FIG. 7, when the interlacing process is completed, a process for actually forming dots on the print medium (dot forming process) is started according to the dot data rearranged by the interlace process (step S112). That is, while the carriage motor 230 is driven to cause the print carriage 240 to perform main scanning, the rearranged dot data is supplied to the ink ejection heads 244 to 247. As a result, ink droplets are ejected from the ink ejection heads 244 to 247 according to the dot data, and dots are appropriately formed in each pixel.

  When one main scan is completed, the paper feed motor 235 is driven to feed the print medium in the sub-scanning direction, and then the carriage motor 230 is driven again to cause the print carriage 240 to perform the main scan. The dot data whose order has been rearranged is supplied to the ink discharge heads 244 to 247 to form dots. By repeating such an operation, dots of each color of C, M, Y, and K are formed on the print medium with an appropriate distribution according to the gradation value of the image data, and as a result, the image is printed. Is done.

  In the image printing process of the present embodiment described above, the image data is corrected so that the white portion of the person is clearly white and the black portion is clearly black. For this reason, a person's face is printed with a good impression, and as a result, it is possible to print a high-quality image in which the performance of the printing apparatus 10 is sufficiently exhibited. Hereinafter, the details of the eye color correction process performed to correct the white and black eye colors during the above-described image printing process will be described.

D. Eye color correction processing:
FIG. 11 is a flowchart showing the flow of eye color correction processing performed during the image printing processing of this embodiment. As shown in the figure, in the eye color correction process, first, the image data to be printed is analyzed to detect a part where a person's eyes are reflected (step S200). The portion where the eye is reflected can be roughly detected as follows.

  First, the contour portion of the object is extracted from the image data. When extracting the contour, use a two-dimensional filter such as a median filter to remove noise, enhance the contrast and edges, and then binarize, and use the resulting binarized image for the boundary of the object. Extract as Next, processing is performed that excludes the extracted contours that are apparently not eyes. For example, an object with a large proportion of straight lines in the extracted contour is highly likely to be a so-called artifact, and is unlikely to be an eye. In this way, objects that can be clearly judged not to be eyes are excluded, and objects that are considered to be “eyes”, “mouth”, “nose”, and the like are extracted from the shape of the outline of the remaining objects.

  If these objects are really “eyes”, “mouth”, “nose”, etc., they should be in a predetermined positional relationship with each other. For example, when an object that seems to be an "eye" is extracted, if the object is really an "eye", there should be an object that looks like an "eye" in the same position at the same height. It is. In addition, an object that looks like a “nose” should exist at a position descending from the position of the center of the second eye, and an object that looks like a “mouth” should exist further below. In this way, by extracting an object that seems to be “eyes”, “mouth”, “nose”, etc. from the contour, and finally considering the mutual positional relationship from among the extracted objects, finally “eyes” It is possible to detect a portion where is shown.

  FIG. 12 shows a state in which a portion where “eye” is reflected is detected based on the positional relationship between “eyes”, “nose”, and “mouth” extracted as described above. In step S200 of FIG. 11, the process of detecting a part in which a person's eyes are reflected from the image is performed as described above.

  Next, it is determined whether an eye part has been detected (step S202). That is, depending on the image to be printed, there are cases where the eyes are detected and cases where the eyes are not detected. In step S200, it is determined whether or not the eyes are detected. If the eye portion is not detected (step S202: no), the eye color correction process shown in FIG. 12 is terminated and the process returns to the image printing process shown in FIG.

  On the other hand, when an eye part is detected (step S202: yes), a histogram of image data is acquired for the eye part (step S204). Next, by analyzing the histogram, a gradation value representing the white-eye portion (white-eye side gradation value) and a gradation value representing the black-eye portion (black-eye side gradation value) are acquired (step S206). ).

  FIG. 13 is an explanatory diagram illustrating a histogram of image data acquired for the eye portion. As shown in the figure, the histogram of the eye portion has peaks at two locations, a bright portion corresponding to the so-called white eye (high tone value) and a dark portion corresponding to the so-called black eye (low tone value). It has a shape to have. In more detail, the black eye part is composed of a pupil part and an iris part around it. The color of the iris is almost black if it is an Eastern person, but in the case of a Western person, the color of the iris is not limited to black and may be blue or gray. In the process of correcting the eye color, it can be corrected by considering it as a black eye part including the iris, or it can be corrected considering only the pupil part as a black eye, but in this embodiment, only the pupil part is corrected. Suppose it is the black eye part. Also, in this embodiment, the average gradation value of the white eye part is used as the white eye side gradation value, and the average gradation value of the black eye (here, pupil) is used as the black eye side gradation value. To do. In step S206 in FIG. 11, processing for obtaining the white-eye side tone value and the black-eye side target value is performed by performing the above analysis on the detected histogram of the eye portion. Here, since the image data is assumed to be RGB image data, the white-eye side tone value and the black-eye side tone value are acquired for each color of RGB.

  Next, a conversion characteristic for converting the gradation value of the image data is generated based on the white-eye gradation value and the black-eye gradation value thus obtained (step S208). Here, the conversion characteristic is a characteristic line in which the gradation value of the image data before conversion is associated with the gradation value of the image data after conversion. By setting appropriate conversion characteristics in advance, it is possible to quickly convert image data.

  FIG. 14 is an explanatory diagram showing a state in which conversion characteristics are set based on the white-eye side tone value and the black-eye side tone value. In setting the conversion characteristics, a target tone value (white eye side target value) for the white eye portion and a target tone value (black eye side target value) for the black eye portion are set in advance. A tone value larger than the white eye side tone value is converted to a value larger than the white eye side target value, and a tone value smaller than the black eye side tone value is converted to a value smaller than the black eye side target value. In this way, the gradation value conversion characteristics are set. The thick solid line shown in the figure indicates the conversion characteristics set in this way. In the eye color correction process of this embodiment, the white eye side target value is set to the gradation value 255, and the black eye side target value is set to the gradation value 0. Therefore, a conversion characteristic is set such that a gradation value larger than the white-eye side gradation value is converted into a gradation value 255, and a gradation value smaller than the black-eye side gradation value is converted into a gradation value 0. The In step S208 of FIG. 11, as described above, tone value conversion characteristics are generated for each of the RGB color components in accordance with the white-eye side tone value and the black-eye side tone value. FIG. 15 is an explanatory diagram conceptually showing how the gradation value conversion characteristics are generated for each of the RGB color components.

  Next, a process of correcting the image data of the eye portion according to the generated conversion characteristics is performed (step S210 in FIG. 11). In other words, the image data of the pixels included in the detected eye portion is read, and then the “gradation value after conversion” when the gradation value of this image data is “gradation value before conversion” is converted. Obtain according to characteristics. In FIG. 15, the manner in which “the gradation value after conversion” is acquired from “the gradation value before conversion” according to the conversion characteristics is indicated by a one-dot chain line arrow. If the gradation value of the uncorrected image data is replaced with the “converted gradation value” thus obtained, the corrected image data can be obtained. As described above, since the average gradation value of the white eye portion is used as the white eye side gradation value, by converting the gradation value in this way, half of the white eye portion is converted to pure white. The other half can also be converted to white. Similarly, with regard to the black eye side gradation value, half of the black eye can be converted to black, and the remaining half can be converted to black. Furthermore, if the iris part is a blackish color, it is converted to black by this conversion, while if the iris color is blue or green, it can be converted so that it is not affected much. it can. When the correction of the image data is completed by performing such an operation on all the pixels constituting the eye part (step S210), the eye color correction process shown in FIG. 11 is terminated and the image printing process of FIG. Return to.

  According to the image printing process of the present embodiment described above, the human eye part is detected from the image data to be printed, and the white part is corrected to be white and the black part is corrected to black. Can be printed. As described above, when a person is included in the print image, if the person's face is not captured with a good impression, the print image quality may be misunderstood. If you print the image with a clear white and black eyes, you can make the face of the person look good and avoid being misunderstood as if the image quality is not high. Can do. As a result, it is possible to print a high-quality image in which the performance of the printing apparatus 10 is sufficiently exhibited.

  Further, when correcting the image data of the eye portion, the correction is performed according to the conversion characteristics as shown in FIG. In the actual image, the color of the eye is also slightly different depending on the location, but by correcting according to the conversion characteristics in this way, it is possible to correct it to a natural feeling while leaving the color difference depending on the location. It becomes. In addition, as described above, since the conversion characteristics can be easily generated from the gradation values representing the white and black portions, the image data can be easily corrected.

E. Modified example:
There are several variations of the eye color correction process of the present embodiment described above. Hereinafter, these modifications will be briefly described.

(1) First modification:
In each of the eye color correction processes described above, it has been described that more than half of the white eye portion is corrected to be pure white. However, a plurality of target white eye colors may be set and a more preferable white eye color may be selected from these.

  FIG. 16 is an explanatory diagram conceptually showing a state in which a plurality of target white eye colors are set in the eye color correction processing of the first modified example. As shown in the figure, target values for R, G, and B components are set for each color of the white of the eye, and when a desired color is selected, conversion characteristics for each component are set accordingly. You may make it.

  FIG. 17 is an explanatory diagram conceptually showing how the conversion characteristics are set according to the color of the selected white eye in the eye color correction process of the first modification. As shown in the drawing, the tone value larger than the white-eye side tone value (the tone value representing the white-eye portion) is larger than the selected white-eye target value (white-eye side target value). Thus, the conversion characteristics may be set. If the image data of the eye portion is corrected in accordance with such conversion characteristics, the white eye portion is printed with almost the target color selected, and the black eye portion is printed with clear blackness. Can be corrected. Further, if the image data is corrected in this way, the correction is performed in a state in which the light and darkness included in the image of the eye portion is inherited (that is, the brighter portion is brighter and the darker portion is darker) Images can be printed.

(2) Second modification:
In the various eye color correction processes described above, the image data is corrected only for the eye portion. However, in the case of correcting the white of the eye to white, the color tone of the entire image may be corrected by taking a white balance based on the color of the white eye.

  FIG. 18 is a flowchart showing the flow of eye color correction processing in the second modification. The eye color correction process of the second modified example is almost the same as the eye color correction process described above with reference to FIG. 11, but in addition to the conversion characteristics for correcting the eye part, the color tone of the image is corrected. The difference is that the conversion characteristic is set, and the image data of the entire image is corrected according to the conversion characteristic for color tone correction. Hereinafter, the eye color correction process of the second modification will be briefly described with the difference as a center.

  Also in the eye color correction process of the second modified example, as in the eye color correction process described above with reference to FIG. 11, first, image data is analyzed to detect a portion where a person's eyes are reflected. Processing is performed (step S250). Next, it is determined whether or not the eye part has been detected (step S252). If the eye part has not been detected (step S252: no), the eye color correction of the second modified example shown in FIG. The process ends. On the other hand, when the eye part has been detected (step S252: yes), a histogram of the image data is acquired at the eye part (step S254), and the acquired histogram is analyzed to obtain the white eye side floor. The tone value and the black eye side tone value are acquired (step S256).

  In the eye color correction process of the second modification example, the conversion characteristics used for correcting the eye portion and the color tone of the entire image are calculated based on the white eye side tone value and the black eye side tone value thus obtained. Conversion characteristics for correction are set (step S258).

  FIG. 19 is an explanatory diagram conceptually showing a state in which conversion characteristics used for correcting the eye portion and conversion characteristics for correcting the color tone of the entire image are set. The conversion characteristics for correcting the eye portion are indicated by solid lines in the figure. As shown in the figure, in the conversion characteristics for the eye portion, a gradation value larger than the white-eye side gradation value is converted into a gradation value 255, and a gradation value smaller than the black-eye side gradation value is converted to a gradation value 0. It is set to a characteristic that converts to. On the other hand, the conversion characteristic for tone correction is that the gradation value larger than the white-eye side gradation value is converted to the gradation value 255, and the gradation value is smaller in the gradation value range smaller than the white-eye side gradation value. As the value becomes smaller, the characteristic is set such that the gradation value decreases linearly from the gradation value 255 to the gradation value 0.

  The image data of the eye part is corrected according to the conversion characteristics for the eye part thus set (step S260). As a result, it is possible to print the white part clearly and white and the black part clearly black.

  On the other hand, the image data of portions other than the eyes are corrected according to the conversion characteristics for color tone correction (step S262). As a result, it is possible to correct the color tone of the entire image so that the portion of the white eye is completely white. Thus, when the image data is corrected according to the conversion characteristics set for the eye portion and the non-eye portion, the eye color correction processing of the second modification shown in FIG. 18 is finished, and the image printing of FIG. Return to processing.

  In the eye color correction process of the second modification described above, the color of the whole image can be corrected at the same time as correcting the color of the white of the eye to pure white. This point will be supplementarily described. For example, in an image shot in the evening or an image shot using a yellow light source, the white eye may be colored due to the influence of the color of the light source. As described above, in an image shot using a colored light source, the color tone of the entire image is shifted to the color tone side of the light source. In order to accurately correct such a color shift, it is not always easy because it is necessary to know what color light source was used for photographing. However, since the white eye of a person is usually close to white, it can be considered that the color of the white eye portion is almost the color of the light source. Therefore, if the entire image is corrected so that the white of the eye becomes a pure white color, the influence of the light source can be corrected and the image can be corrected to the correct color. As a result, a higher quality image can be printed.

  In the second modification described above, the color of the white part may be selectable as in the first modification described above. That is, the image data is corrected using the same characteristics as the conversion characteristics of the first modification shown in FIG. 17 for the eyes, and the parts other than the eyes are those of the second modification shown in FIG. The image data may be corrected using the conversion characteristics. FIG. 20 is an explanatory diagram conceptually showing a state in which conversion characteristics for correcting a white-eye portion to a desired white color and conversion characteristics for correcting the color tone of the entire image are set. If the image data of the eye portion and the image data of the entire image are corrected according to such conversion characteristics, the image quality of the whole image is corrected by correcting the color tone of the entire image while correcting the white eye portion to the desired white. It is possible to print a clear image.

  Although the printing apparatus of the present embodiment has been described above, the present invention is not limited to all the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.

It is explanatory drawing which showed the outline | summary of the printing apparatus of a present Example. It is a perspective view which shows the external appearance shape of the printing apparatus of a present Example. FIG. 6 is an explanatory diagram showing a state in which a document table cover provided on the upper part of the printing apparatus is opened to read a document image. It is the perspective view which showed a mode that the front side of the scanner part was lifted and rotated. It is explanatory drawing which showed notionally the internal structure of the printing apparatus of a present Example. It is explanatory drawing which showed a mode that the several nozzle which discharges an ink drop to the ink discharge head of each color was formed. 3 is a flowchart illustrating a flow of image printing processing performed to print an image with the printing apparatus according to the present exemplary embodiment. It is explanatory drawing which showed notionally the color conversion table referred for a color conversion process. It is explanatory drawing which expanded and illustrated a part of dither matrix. It is explanatory drawing which showed notionally the mode that the presence or absence of dot formation was judged for every pixel, referring a dither matrix. It is a flowchart which shows the flow of the eye color correction process performed in the image printing process of a present Example. It is explanatory drawing which shows a mode that the part in which the person's eyes were reflected in the image was detected. It is explanatory drawing which illustrated the histogram of the image data acquired about the eye part. It is explanatory drawing which shows a mode that the conversion characteristic is set based on the white-eye side gradation value and the black-eye side gradation value. It is explanatory drawing which showed notionally the conversion characteristic of the gradation value produced | generated for every RGB color component according to the white-eye side gradation value and the black-eye side gradation value. It is explanatory drawing which showed notionally the mode that multiple colors of the target white eye were set in the eye color correction process of the 1st modification. It is explanatory drawing which showed notionally the mode that a conversion characteristic was set according to the color of the selected white eye in the eye color correction process of a 1st modification. It is a flowchart which shows the flow of the eye color correction process in a 2nd modification. FIG. 10 is an explanatory diagram conceptually showing a state in which conversion characteristics used for correcting an eye portion and conversion characteristics for correcting the color tone of an entire image are set in a second modification. In the 2nd modification, it is explanatory drawing which showed notionally the other aspect which has set the conversion characteristic which correct | amends the part of a white eye to favorite white, and the conversion characteristic which corrects the color tone of the whole image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 12 ... Ink discharge head, 100 ... Scanner part,
200: Printer unit, 240: Print carriage, 241: Print head,
242 ... Ink cartridge, 243 ... Ink cartridge,
260 ... control circuit, 300 ... operation panel

Claims (13)

A printing apparatus that receives image data of an image taken including at least a person and prints the image,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion; ,
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. Conversion characteristic setting means for setting the conversion characteristic of the gradation value to be converted into
Image data correction means for correcting the image data of the eye part according to the set conversion characteristics;
An image printing unit that prints the image based on the corrected image data. The printing apparatus according to claim 1,
The conversion characteristic setting means includes
White-eye target value storage means for storing a plurality of white-eye target values;
A white-eye target value selecting means for selecting one target value from the plurality of stored white-eye target values;
A printing apparatus which is means for setting the conversion characteristics such that the white-eye side tone value is converted to a value larger than the selected white-eye target value. A printing apparatus that receives image data of an image taken including at least a person and prints the image,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
White-eye side tone value extracting means for extracting a white-eye side tone value that is a tone value representative of the white-eye portion from the detected eye portion;
Conversion characteristic setting means for setting the conversion characteristic of the gradation value so that the white-eye side gradation value matches a preset reference white gradation value;
A tone correction unit that corrects the tone of the image data by converting the tone value of the image data according to the set conversion characteristics;
A printing apparatus comprising: an image printing unit that prints the image based on the image data in which the color tone is corrected. An image processing apparatus that receives image data of an image captured including at least a person and performs predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
Gradation value extracting means for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion; ,
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. Conversion characteristic setting means for setting the conversion characteristic of the gradation value to be converted into
An image processing apparatus comprising: image data correcting means for correcting image data of the eye portion according to the set conversion characteristic. An image processing apparatus that receives image data of an image captured including at least a person and performs predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected;
White-eye side tone value extracting means for extracting a white-eye side tone value that is a tone value representative of the white-eye portion from the detected eye portion;
Conversion characteristic setting means for setting the conversion characteristic of the gradation value so that the white-eye side gradation value matches a preset reference white gradation value;
An image processing apparatus comprising: a color tone correcting unit that corrects a color tone of the image data by converting a gradation value of the image data according to the set conversion characteristic. A printing method for receiving image data of an image taken including at least a person and printing the image,
A first step of analyzing the image data to detect a portion of the image data in which a human eye is reflected;
A second step of extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing a white-eye part and a black-eye side gradation value that is a gradation value representing a black-eye part;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A third step of setting gradation value conversion characteristics such that
A fourth step of correcting the image data of the eye portion according to the set conversion characteristic;
And a fifth step of printing the image based on the corrected image data. A printing method for receiving image data of an image taken including at least a person and printing the image,
Analyzing the image data to detect a portion of the image data in which a human eye is reflected (A);
A step (B) of extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A step (C) of setting a gradation value conversion characteristic so that the white-eye side gradation value matches a preset reference white gradation value;
(D) correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics;
And a step (E) of printing the image based on the image data in which the color tone is corrected. An image processing method for receiving image data of an image captured including at least a person and performing predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a person's eyes are reflected (1);
A step (2) of extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing a white-eye part and a black-eye side gradation value that is a gradation value representing a black-eye part;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A step (3) of setting a conversion characteristic of the gradation value so as to be converted into
An image processing method comprising: (4) correcting the image data of the eye portion according to the set conversion characteristics. An image processing method for receiving image data of an image captured including at least a person and performing predetermined image processing,
Analyzing the image data to detect a portion of the image data in which a human eye is reflected (a);
Extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A step (c) of setting a gradation value conversion characteristic so that the white-eye side gradation value matches a preset reference white gradation value;
And (d) correcting the color tone of the image data by converting the gradation value of the image data in accordance with the set conversion characteristics. A program for realizing, using a computer, a method for receiving image data of an image photographed including at least a person and printing the image,
A first function for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A second function of extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing a white-eye portion and a black-eye side gradation value that is a gradation value representing a black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A third function for setting the conversion characteristic of the gradation value so as to be converted into
A fourth function for correcting the image data of the eye portion according to the set conversion characteristic;
A program that implements a computer. A program for realizing, using a computer, a method for receiving image data of an image photographed including at least a person and printing the image,
A function (A) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (B) for extracting a white-eye side gradation value, which is a gradation value representing the white-eye part, from the detected eye part;
A function (C) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
A function (D) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics;
A program for realizing, by a computer, a function (E) for printing the image based on the image data whose color tone has been corrected. A program for realizing, using a computer, a method for receiving image data of an image captured including at least a person and performing predetermined image processing,
A function (1) for detecting a portion of the image data in which human eyes are reflected by analyzing the image data;
A function (2) for extracting, from the detected eye portion, a white-eye side gradation value that is a gradation value representing the white-eye portion and a black-eye side gradation value that is a gradation value representing the black-eye portion;
The white eye side tone value is converted to a value larger than a preset white eye side target value, and the black eye side tone value is a value smaller than the preset black eye side target value. A function (3) for setting the conversion characteristic of the gradation value so as to be converted into
A program for realizing, by a computer, the function (4) for correcting the image data of the eye portion in accordance with the set conversion characteristics. A program for realizing, using a computer, a method for receiving image data of an image captured including at least a person and performing predetermined image processing,
By analyzing the image data, a function (a) for detecting a portion of the image data where a human eye is reflected;
A function (a) for extracting, from the detected eye part, a white-eye side gradation value that is a gradation value representing the white-eye part;
A function (c) for setting gradation value conversion characteristics so that the white-eye side gradation value matches a preset reference white gradation value;
A program for realizing, by a computer, a function (d) for correcting the color tone of the image data by converting the gradation value of the image data according to the set conversion characteristics.

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