Patent Publication Number: US-2009237679-A1

Title: Image processing device and method for image processing

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to an image processing technology for deforming an image. 
     2. Related Art 
     An image processing technology for deforming and reducing a human face included in a digital image is known as disclosed in JP-A-2004-318204. An image processing device disclosed in JP-A-2004-318204 is configured to set a portion of an image of a face (portion representing an image of a cheek) as a correction area, to divide the correction area into a plurality of sub-areas in accordance with a determined pattern, and to expand or reduce the image at a magnification set sub-area by sub-area so as to deform the facial shape. 
     The image processing technology of correcting the image by setting the correction area, however, requires a large amount of arithmetic operation such as setting the correction area, expanding or reducing the sub-areas and so on. Thus, the amount of arithmetic operation may often be excessively large. The above problem is not limited to a case of deforming the human face, and is common to processes for deforming an image in general. 
     SUMMARY 
     An advantage of some aspects of the invention is to reduce an amount of arithmetic operation required by an image deformation process for deforming an image. 
     Another advantage of some aspects of the invention is to at least partially address the above problem. The invention can be implemented as following embodiments or applications. 
     First Application 
     An image processing device including a deformation area setting unit configured to set an extension area and a reduction area in an image, and a deformation processing unit configured to extend the extension area in a particular direction, the deformation processing unit being configured to reduce the reduction area in the particular direction at a constant reduction rate. 
     According to the first application, the image processing device deforms the image by extending and reducing the image in one direction so that an amount of arithmetic operation required by the image deformation process can be reduced. The image processing device sets the reduction rate to be constant in the reduction area so as to suppress a feeling of wrongness of the deformed image caused by a change of the reduction rate within the reduction area. 
     Second Application 
     The image processing device according to the first application, wherein the deformation processing unit is configured to assign a first extension rate and a second extension rate to a first position and a second position in the extension area, respectively, the second position being nearer to the reduction area than the first position, the second extension rate being smaller than the first extension rate. 
     According to the second application, the extension rate of the second position that is nearer to the reduction area is smaller than the extension rate of the first position that is distant from the reduction area. Thus, as a change of the magnification between the reduction area and the extension area is suppressed, the image processing device can suppress a feeling of wrongness of the deformed image. 
     Third Application 
     The image processing device according to the second application, wherein the deformation processing unit is configured to extend the extension area in the particular direction at an extension rate monotonously increasing with a distance in the particular direction from the reduction area. 
     The image processing device makes the extension rate monotonously increase with the distance in the particular direction from the reduction area so as to reduce a change rate of the extension rate in the particular direction in the extension area. Thus, the image processing device can suppress a feeling of wrongness of the deformed image caused by an abrupt change of the extension rate in the particular direction. 
     Fourth Application 
     The image processing device according to the first application, wherein the image includes a human face, and the deformation area setting unit is configured to set the reduction area in such a way that the reduction area includes the human face. 
     In general, if an amount of deformation of a facial shape is not uniform, the deformed image produces a feeling of wrongness. According to the fourth application, as the reduction area in which the reduction rate is constant includes the human face, the face can be more uniformly deformed. Thus, the image processing device can suppress a feeling of wrongness of the deformed image. 
     The invention can be implemented in various forms such as a method and a device for image processing, an image output device and a method for outputting an image using the above method and device for image processing, a computer program for implementing the above methods and functions of the above devices, a storage medium on which the above computer program is recorded, a data signal including the above computer program and implemented in a carrier wave, and so on. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a schematic block diagram of a printer of a first embodiment. 
         FIG. 2  illustrates an example of a user interface screen including a list of images. 
         FIG. 3  is a flowchart of a facial shape correction print process performed upon the printer performing facial shape correction printing. 
         FIGS. 4A-4C  illustrate an example of the facial shape correction process in which an image corresponding to a thumbnail TN 1  shown in  FIG. 2  is corrected. 
         FIG. 5  is a flowchart of a deformation process performed at a step S 400 . 
         FIGS. 6A-6C  show a model of the deformation process in a case where a direction of deformation is horizontal. 
         FIGS. 7A-7C  illustrate a facial shape correction process in which an image corresponding to a thumbnail image TN 2  shown in  FIG. 2  is corrected. 
         FIGS. 8A and 8B  illustrate a facial shape correction process of a second embodiment in which an image corresponding to a thumbnail image TN 1  shown in  FIG. 2  is corrected. 
         FIG. 9  is a schematic block diagram of a printer of a third embodiment. 
         FIG. 10  is a flowchart of a facial shape correction print process of the third embodiment. 
         FIGS. 11A and 11B  illustrate a facial shape correction process of the third embodiment in which the image corresponding to the thumbnail image TN 1  shown in  FIG. 2  is corrected. 
         FIGS. 12A and 12B  illustrate a facial shape correction process in which an image corresponding to a thumbnail image TN 3  shown in  FIG. 2  is corrected. 
         FIG. 13  is a schematic block diagram of a printer of a fourth embodiment. 
         FIG. 14  is a flowchart of a facial shape correction print process of the fourth embodiment. 
         FIGS. 15A and 15B  illustrate a facial shape correction process of the fourth embodiment in which the image corresponding to the thumbnail image TN 3  shown in  FIG. 2  is corrected. 
         FIG. 16  is a schematic block diagram of a printer of a fifth embodiment. 
         FIG. 17  is a flowchart of a facial shape correction print process of the fifth embodiment. 
         FIGS. 18A-18C  illustrate a facial shape correction process of the fifth embodiment in which the image corresponding to the thumbnail image TN 1  shown in  FIG. 2  is corrected. 
         FIGS. 19A and 19B  illustrate an example of a facial arrangement identification process performed at a step S 200  shown in  FIG. 3 . 
         FIG. 20  illustrates an example of a facial arrangement identification process performed at a step S 800   d  shown in  FIG. 17 . 
         FIG. 21  illustrates another example of the facial arrangement identification process performed at the step S 800   d  shown in  FIG. 17 . 
         FIG. 22  illustrates still another example of the facial arrangement identification process performed at the step S 800   d  shown in  FIG. 17 . 
         FIG. 23  illustrates yet another example of the facial arrangement identification process performed at the step S 800   d  shown in  FIG. 17 . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Embodiments of the invention will be described in following paragraphs in order.
     A. First Embodiment   B. Second Embodiment   C. Third Embodiment   D. Fourth Embodiment   E. Fifth Embodiment   F. Facial Arrangement Identification   G. Facial Area Deformation   H. Modifications   

     A. First Embodiment 
       FIG. 1  is a schematic block diagram of a printer  100  of the first embodiment of the invention. The printer  100  is a color inkjet printer adapted for so-called direct printing configured to print an image on the basis of image data obtained from a memory card MC and so on. The printer  100  has a printer controller  110  configured to control each of portions of the printer  100 , an operation section  120  constituted by buttons and a touch-panel, a display unit  130  constituted by a liquid crystal display device, a print engine  140 , and a card interface  150 . The printer  100  may further have an interface configured to perform data communication with other devices (e.g., a digital still camera or a personal computer). 
     The print engine  140  is a printing mechanism configured to perform printing on the basis of print data. The card interface  150  is an interface for exchanging data with the memory card MC loaded into a card slot  152 . The memory card MC of the first embodiment stores image data being RGB data. The printer  100  may obtain the image data stored in the memory card MC through the card interface  150 . 
     The printer controller  110  has functional blocks that are a facial shape correction processor  200 , a display processor  310 , and a print processor  320 . The printer controller  110  is constituted as a computer having a CPU, a ROM and a RAM (which are not shown). The CPU is configured to work as the above functional blocks  200 ,  310  and  320  by running programs stored in the ROM or the RAM. 
     The display processor  310  is configured to control the display unit  130  so as to display a processing menu or a message on the display unit  130 . The print processor  320  is configured to generate the print data from the image data, and to control the print engine  140  so as to print an image based on the print data. 
     The facial shape correction processor  200  has a deformation direction setting unit  210 , a facial arrangement identification unit  220  and a directional correction process unit  230 . The directional correction process unit  230  has a corresponding pixel number table generator  232  and a corresponding pixel arrangement process unit  234 . The directional correction process unit  230  is configured to perform a facial shape correction process by using an image buffer  410  and a corresponding pixel number table  420  both included in a process buffer  400  that is an area for temporary memory arranged in the RAM. A function of each of the above portions will be described later. 
     The printer  100  is configured to print an image on the basis of image data stored in the memory card MC. If the card slot  152  is loaded with the memory card MC, the display controller  310  displays on the display unit  130  a user interface screen including a list of images stored in the memory card MC.  FIG. 2  shows an example of the user interface screen including the list of the images. The list of the images of the embodiment is implemented by using thumbnail images included in the image data (image files) stored in the memory card MC. The user interface screen shown in  FIG. 2  includes eight thumbnail images TN 1 -TN 8  and five buttons BN 1 -BN 5 . The deformation direction setting unit  210  corresponds to a deformation area setting unit. The directional correction process unit corresponds to a deformation processing unit. 
     If a user selects one of the images on the user interface screen shown in  FIG. 2  and presses the ordinary print button BN 3 , the printer  100  performs ordinary printing, i.e., print the selected image as usual. Meanwhile, if the user selects one of the images on the user interface screen and presses the facial correction print button BN 4 , the printer  100  performs a facial shape correction process on the selected image so as to reduce a width of a face of the selected image, and prints the corrected image. As shown in  FIG. 2 , e.g., the thumbnail image TN 1  is selected and the facial correction print button BN 4  is pressed. Thus, the printer  100  performs the facial shape correction process on the image corresponding to the thumbnail image TN 1 , and prints the corrected image. 
       FIG. 3  is a flowchart showing a flow of a facial shape correction print process that the printer  100  performs for facial shape correction printing. The CPU of the printer controller  110  may perform the facial shape correction print process in response to a user&#39;s operation on the facial correction button print BN 4  on the user interface screen shown in  FIG. 2 .  FIGS. 4A-4C  illustrate an example of the facial shape correction process in which an image IG 1  corresponding to the thumbnail image TN 1  is corrected and a corrected image IT 1  is produced. 
     At a step S 100 , the facial shape correction unit  200  (shown in  FIG. 1 ) obtains an image to be corrected by the facial shape correction process. More specifically, the facial shape correction unit  200  reads from the memory card MC the image (object image) corresponding to the thumbnail image TN 1  selected by the user on the user interface screen shown in  FIG. 2 , and stores the object image in the image buffer  410 . Hereinafter, the image to be corrected by the facial shape correction process may be called the “original image”. 
     At a step S 200 , the facial arrangement identification unit  220  (shown in  FIG. 1 ) analyzes the original image so as to identify an arrangement of the human face in the original image. More specifically, the facial arrangement identification unit  220  detects the human face and identifies an inclination of the detected face to the image. As for the first embodiment, long and short sides of the image are in horizontal and vertical directions, respectively. Thus, the inclination of the face is a degree between a top-to-bottom direction of the face and the vertical direction (i.e., the short side direction) of the image. A specific method for identifying the facial arrangement will be described later. As detecting the human face while identifying the facial arrangement, the facial arrangement identification unit  220  has a function of a “face detector”. As long as the facial arrangement may be identified, the face detector may detect at least one organ included in the face, or may detect a whole head. As being determined to the face, the top-to-bottom or left-to-right direction of the face may be called a direction preset to the face. 
     As shown in  FIG. 4A , e.g., a face FG 1  positioned almost in the middle of the original image IG 1  is detected, and the inclination of the face FG 1  is identified. As shown in  FIG. 4A , the top-to-bottom direction of the face FG 1  almost coincides with the vertical direction of the image IG 1 . Thus, the inclination of the face identified at the step S 200  is almost zero degrees. 
     At a step S 300  shown in  FIG. 3 , the deformation direction setting unit  210  sets a direction of deformation, i.e., an extension and a reduction, in the facial shape correction process on the basis of the facial arrangement identified at the step S 200 . More specifically, if the inclination of the face obtained at the step S 200  is smaller than 45 degrees, the direction of deformation is set in the horizontal direction of the image. Meanwhile, if the inclination of the face is greater than 45 degrees, the direction of deformation is set to be vertical. If the inclination of the face is 45 degrees, the direction of deformation is set in a standard direction (e.g., horizontal) that has been determined in advance. It the image data includes Exif information, the direction of deformation may be set on the basis of position change information included in the Exif information instead of in the standard direction. If the inclination of the face is in a determined range including 45 degrees (e.g., 43-47 degrees), the direction of deformation may be set in the standard direction or on the basis of the position change information. 
     As described later, the top-to-bottom direction of the face is identified as a direction perpendicular to a direction connecting two pupils of the detected face. Thus, the direction of deformation is set in one of the horizontal and vertical directions of the image that makes a smaller degree with the direction connecting the pupils. 
     If the image includes a plurality of faces, the direction of deformation is set by preferably using a greater one of the faces. That is, if the inclination of the greater face is smaller than 45 degrees and the inclination of the smaller face is greater that 45 degrees, the direction of deformation is set to be horizontal. If the image includes a plurality of faces, though, the direction of deformation may be set by using other methods. The direction of deformation may be set on the basis of the inclination of the face closest to zero or ninety degrees, or on the basis of a direction of an arrangement of the plural faces. 
     As shown in  FIG. 4A , e.g., the inclination of the face FG 1  is almost zero degrees so that the direction of deformation is set in the horizontal direction of the image IG 1  at the step S 300  (shown in  FIG. 3 ). 
     At a step S 400 , the directional correction process unit  230  (shown in  FIG. 1 ) performs a directional correction process for reducing and extending the original image in the direction of deformation so as to produce a corrected image. More specifically, the directional correction process unit  230  reduces and extends in the direction of deformation a reduction area of a determined width arranged in the middle of the direction of deformation and extension areas arranged outside the reduction area, respectively. The width of the reduction area may be set on the basis of a width of the face detected at the step S 200 , or a length of the original image in the direction of deformation. The reduction area may be set to, e.g., two and a half times as wide as the face, or to half as long as the direction of deformation. 
     on an image where a person is photographed, as usual, the person is arranged in the middle of the image. Thus, by arranging the reduction area in the middle of the original image, the human face included in the image is deformed and slims down. Although the first embodiment is given a reduction rate determined beforehand (e.g., 90 percent), the user may instruct to change the reduction rate. An extension rate of the extension area is properly set on the basis of the width and the reduction rate of the reduction area. A specific configuration of the directional deformation process will be described later. 
     As for the first embodiment, as shown in  FIG. 4A , a reduction area SG is arranged in the middle of the horizontal direction (direction of deformation) of the original image, and an extension area EG is arranged at each of the left and right outsides of the reduction area SG. Due to the directional correction process, as shown in  FIG. 4B , the reduction area SG of the original image IG 1  is deformed to a reduction area SM having a reduced length in the direction of deformation, and each of the extension areas EG of the original image IG 1  is deformed to an extension area EM having an extended length in the direction of deformation. Thus, a face FM 1  of a deformed image IM 1  is slimmer than the face FG 1  of the original image IG 1 . 
       FIG. 5  is a flowchart of the directional deformation process performed at the step S 400 .  FIGS. 6A-6C  shows a model of the directional deformation process in a case where the direction of deformation is horizontal.  FIG. 6A  shows an arrangement of pixels before the directional deformation process, i.e., before the correction.  FIG. 6B  shows an example of the corresponding pixel number table  420 . FIG.  6 C shows an arrangement of pixels of an image that has been directionally deformed (deformed image). 
     At a step S 410 , the directional correction process unit  230  judges in which direction, horizontal or vertical, the direction of deformation has been set. If the direction of deformation is horizontal, the flow moves on to a step S 422 . If the direction of deformation is vertical, the flow moves on to a step S 442 . 
     At the step S 422 , a corresponding pixel number table generator  232  of the directional correction process unit  230  makes the corresponding pixel number table  420 . The corresponding pixel number table  420  is a table representing the number of pixels of the deformed image each of which corresponds to each of pixels of the original image. The corresponding pixel number table generator  232  determines the number of the corresponding pixels of the deformed image (corresponding pixel number) on the basis of the reduction rate and the extension rate (magnification) set in each of areas of the image arranged in the horizontal direction. Then, the corresponding pixel number table generator  232  stores the determined corresponding pixel number in the corresponding pixel number table  420  so as to make the corresponding pixel number table  420 . As for the first embodiment, if the direction of deformation is horizontal, the image is deformed to be left-to-right symmetric. Thus, it is enough for the corresponding pixel number table  420  to have a half as many as the whole number of the pixels in the horizontal direction, so that a memory size required for the directional deformation process may be reduced. 
     The corresponding pixel number table generator  232  can determine the corresponding pixel number by, e.g., binary-digitizing a decimal portion of the magnification by using a half tone process so as to determine an arrangement pattern of “0”s and “1”s, and by adding an integer portion of the magnification to the value “0” or “1” of the arrangement pattern. The corresponding pixel number table generator  232  can use a known method such as dithering or error diffusion for the half tone process. The corresponding pixel number table generator  232  can use an arrangement pattern stored beforehand for the decimal portion of each of the magnifications. At the step S 422 , the corresponding pixel number table generator  232  may use a corresponding pixel number table that has been made beforehand instead of making the corresponding pixel number table. 
     As shown in  FIG. 6 , e.g., the magnifications in the horizontal direction are set to 0.6, and 1.6 for every five pixels from the middle of the original image. Thus, for each of three pixels Px 1 , Px 3  and Px 5  of the initial five pixels Px 1 -Px 5 , the corresponding pixel number is set to one. For each of the remaining two pixels Px 2  and Px 4 , the corresponding pixel number is set to zero. For each of all the next five pixels Px 6 -Px 10  for which the magnification is set to one, the corresponding pixel number is set to one. For each of three pixels Px 11 , Px 13  and Px 15  of the outmost five pixels of the original image for which the magnification is set to 1.6, the corresponding pixel number is set to two. For each of the remaining two pixels Px 12  and Px 14  of the outmost five pixels, the corresponding pixel number is set to one. 
     At a step S 424  shown in  FIG. 5 , the corresponding pixel arrangement process unit  234  (shown in  FIG. 1 ) rearranges the pixels on a line of the original image stored in the image buffer  410 . The line is a process unit for processing an image, and is a linear area extended in the horizontal direction that is as long as the whole pixel number in the horizontal direction, and is as wide as one pixel. Depending on a method for storing the image in the image buffer  410 , however, a linear area extending in the vertical direction may be treated as the line. 
     The corresponding pixel arrangement process unit  234  (shown in  FIG. 1 ) rearranges the pixels stored in the image buffer  410  outwards from the middle of the image in accordance with the corresponding pixel number stored in the corresponding pixel number table  420 . The corresponding pixel arrangement process unit  234  can rearrange the pixels in condition that pixels not yet rearranged remain in the image buffer  410  by rearranging the pixels outwards from the middle of the image. Thus, the corresponding pixel arrangement process unit  234  can rearrange the pixels by using the single image buffer  410  so that a memory size required for the directional deformation process may be reduced. 
     As shown in  FIG. 6C , e.g., the pixels Px 1 , Px 3 , Px 5 -Px 10  for each of which the corresponding pixel number is set to one are rearranged from the middle of the image in order. Then, in accordance with the corresponding pixel number, the pixels Px 11 , Px 12 , Px 13 , Px 14  and Px 15  are rearranged to two pixels, one pixel, two pixels, one pixel and two pixels, respectively. The middle and outmost areas of the original image of five pixels are reduced at a magnification of 0.6 times and extended at a magnification of 1.6 times, respectively. As for the first embodiment, as shown in  FIGS. 6A-6C , the magnification of each of the areas in the horizontal direction is set in such a way that the number of the pixels after the rearrangement is a bit greater than the number of the pixels of the original image. Thus, the deformed image is longer than the original image in the direction of deformation. 
     At a step S 426  shown in  FIG. 5 , the directional correction process unit  230  judges if the rearrangement of the pixels is completed for all the lines of the original image. In a case where the rearrangement of the pixels is completed for all the lines of the original image, the directional deformation process shown in  FIG. 5  ends, and the flow moves back to the facial shape correction print process shown in  FIG. 3 . Meanwhile, in a case where the rearrangement of the pixels is not completed, the flow moves back to the step S 424 , and the steps S 424  and S 426  are repeated until the rearrangement of the pixels is completed for all the lines. 
     At the step S 442 , the corresponding pixel number table generator  232  makes the corresponding pixel number table  420  similarly as at the S 422 . In a case where the direction of deformation is vertical, the corresponding pixel number table  420  is made in accordance with the number of the pixels arranged in the vertical direction. As a method for determining the number of the corresponding pixels is a same as that of the step S 422 , its explanation is omitted. 
     At a step S 444 , the directional correction process unit  230  arranges a line of the original image in a storage area of the deformed image set in the image buffer  410  with reference to the corresponding pixel number table  420 . More specifically, in the storage area of the deformed image of the image buffer  410 , the directional correction process unit  230  adds one line of the original image stored in the image buffer  410  as a line of the corresponding pixel number. 
     At a step S 446 , the directional correction process unit  230  judges if the arrangement of all the lines of the original image is completed. In a case where the arrangement of all the lines is completed, the directional deformation process shown in  FIG. 5  ends, and the flow moves back to the facial shape correction print process shown in  FIG. 3 . Meanwhile, in a case where the arrangement of the lines is not completed, the flow moves back to the step S 444 , and the steps S 444  and S 446  are repeated until the arrangement of all the lines is completed. 
     After the flow comes back from the directional deformation process shown in  FIG. 5 , at a step S 500  shown in  FIG. 3 , the directional correction process unit  230  trims the deformed image. As for the first embodiment, as shown in  FIG. 4B , the directionally deformed image is made longer than the original image in the direction of deformation. Thus, a trimming process, i.e., cutting away edge portions in the direction of deformation of the deformed image is performed so that the deformed image becomes a corrected image having a same length as the original image. As shown in  FIG. 4B , left and right edge portions of the deformed image IM 1  are cut away so that the corrected image IT 1  having a same length as the original image IG 1  in the horizontal direction is produced. 
     At a step S 600  shown in  FIG. 3 , the print processor  320  performs a color conversion process, a half tone process and so forth on the corrected image so as to produce print data. The print processor  320  provides the print engine  140  with the produced print data so as to print an image on which the facial shape correction process has been performed. 
       FIGS. 7A-7C  illustrate an example of the facial shape correction process in which an image IG 2  corresponding to the thumbnail image TN 2  shown in  FIG. 2  is corrected.  FIG. 7A  shows the original image IG 2  before the facial shape correction process.  FIG. 7B  shows the deformed image IM 2  that has been directionally deformed at the step S 400 .  FIG. 7C  shows the corrected image IT 2  that has been trimmed at the step S 500 . 
     As shown in  FIG. 7A , as a top-to-bottom direction of a face FG 2  of the original image IG 2  almost coincides with the horizontal direction of the image IG 2 , the inclination of the face is identified to be almost 90 degrees at the step S 200 . Thus, at the step S 300  (shown in  FIG. 3 ), the direction of deformation is set to the vertical direction of the original image IG 2 . 
     As shown in  FIG. 7 , e.g., as the direction of deformation is vertical, a reduction area SGv is arranged in the middle of the vertical direction of the original image IG 2 . High and low outmost areas SGv of the image IG 2  above and below the reduction area SGv are set to be extension areas. Then, at the step S 400 , the original image IG 2  is directionally deformed so that the deformed image IM 2  shown in  FIG. 7B  is produced. Due to the directional deformation process, a reduction area SMv of the deformed image IM 2  is made shorter than the reduction area SGv of the original image IG 2  in the direction of deformation (vertical direction). An extension area EMv of the deformed image IM 2  is made longer than the extension area EGv of the original image  1 G 2  in the vertical direction. Thus, also in a case where the top-to-bottom direction of the face FG 2  is in the horizontal direction of the original image IG 2 , a face FM 2  of the deformed image IM 2  is made slimmer than the face FG 2  of the original image IG 2 . After the deformed image IM 2  is produced, as shown in  FIG. 7C , top and bottom end portions of the deformed image IM 2  are cut away so that the deformed image IM 2  is trimmed and the corrected image IT 2  having a same length as the original image IG 2  in the vertical direction is produced at the step S 500 . 
     According to the first embodiment, as described above, the direction of deformation is set on the basis of the facial arrangement of the original image and the original image is extended and reduced in the direction of deformation, so that the human face may be made slim regardless of the direction of the face. 
     According to the first embodiment, in a case where the direction of deformation is horizontal, i.e., equal to the direction of the line that is the image processing unit, the reduction and extension areas may be arranged symmetric with respect to the middle of the image so that the memory size required for the deformation in the direction of the line may be reduced. 
     As for the first embodiment, after the corrected image is produced at the step S 500  of the trimming process, the print data is produced at the step S 600 . Instead, the print data may be produced after the process for each of the lines is completed at the step S 424  or S 444  (shown in  FIG. 5 ). In that case, if the direction of deformation is horizontal, pixels of both ends of each of the lines are cut away so that the image is trimmed. Meanwhile, if the direction of deformation is vertical, the directional deformation process is performed from the line initially processed in order, and then stopped after a determined number of the lines are processed so that the image is trimmed. Thus, one of the end portions of the deformed image in the vertical direction has been cut away in the trimmed corrected image. 
     B. Second Embodiment 
       FIGS. 8A and 8B  illustrate a facial shape correction process of the second embodiment in which the image IG 1  corresponding to the thumbnail image TN 1  shown in  FIG. 2  is corrected. The second embodiment is different from the first embodiment shown in  FIG. 4  in a way of extending the extension area. Other than that, the second embodiment equals the first embodiment. 
     As for the second embodiment, as shown in FIG. BA, three extension areas EG 1 -EG 3  are arranged at each of the left and right outsides of the reduction area SG. Extension rates of these extension areas EG 1 -EG 3  are set to increase in order from the middle of the direction of deformation towards the outside. Thus, as for a deformed image IM 1   a  shown in  FIG. 8B , an image of an extension area EM 1   a  on a side of the reduction area SM is deformed little, and an image of an outmost extension area EM 3   a  is significantly deformed. 
     As for the second embodiment, as described above, the extension rate of the extension area EG 1  on the side of the reduction area SG is made so small that a feeling of wrongness between the reduction area SM and the extension area EM 1   a  of the deformed image IM 1   a  caused by difference of the magnification is reduced. The extension rate of the outmost extension area EG 3  is made so great that the deformed image IM 1   a  may be long enough in the direction of deformation. The deformed image IM 1   a  can be prevented from producing a blank at an end portion of the direction of deformation, thereby. 
     As for the second embodiment, the three extension areas of different extension rates EG 1 -EG 3  are arranged outside the reduction area SG. Generally speaking, though, it is enough that the extension rate at a position close to the reduction area is smaller than the extension rate at a position distant from the reduction area. The extension rate need not monotonously increase with the distance from the reduction area. As the extension rate at the position close to the reduction area is made small in this way, the feeling of wrongness produced between the reduction area and the extension area of the deformed image can be reduced. 
     C. Third Embodiment 
       FIG. 9  is a schematic block diagram of a printer  100   b  of the third embodiment. The printer  100   b  is different from the printer  100  of the first embodiment in that a facial shape correction processor  200   b  has a reduction area width setting unit  240   b . Other than that, the printer  100   b  equals the printer  100  of the first embodiment. 
       FIG. 10  is a flowchart of a facial shape correction print process of the third embodiment. The flowchart shown in  FIG. 10  is different from the flowchart of the facial shape correction print process of the first embodiment in that a step S 700  is added between the steps S 300  and S 400 . 
     At the step S 700 , the reduction area width setting unit  240   b  sets a width of the reduction area of the original image on the basis of the facial arrangement identified at the step S 200 . More specifically, the reduction area width setting unit  240   b  sets the width of the reduction area so that the face in which the arrangement has been identified at the step S 200  is included in the reduction area. 
       FIG. 11  illustrates a facial shape correction process in which the image IG 1  corresponding to the thumbnail image TN 1  shown in  FIG. 2  is corrected.  FIG. 12  illustrates a facial shape correction process in which the image IG 3  corresponding to the thumbnail image TN 3  shown in  FIG. 2  is corrected.  FIG. 11  is a same drawing as  FIG. 4 . In  FIG. 12 , the original image IG 3  to be corrected in the facial shape correction process is different from the original image IG 1  shown in  FIG. 11 . 
     As shown in  FIG. 11 , if the face FG 1  of the original image IG 1  is positioned in the middle of the original image IG 1 , the width of the reduction area SG is set on the basis of the width of the face FG 1 . Thus, as for the example shown in  FIG. 11 , the reduction area SG and the extension area EG are set similarly to the first embodiment. The original image IG 1  is directionally deformed similarly to the first embodiment. Each of the widths of the reduction area SG and the extension area EG is a same as that of the first embodiment shown in  FIG. 4 . 
     Meanwhile, as shown in  FIG. 12A , the original image IG 3  corresponding to the thumbnail image TN 3  shown in  FIG. 2  equals the original image IG 1  shown in  FIG. 11  in that the top-to-bottom direction of the human face almost coincides with the vertical direction, and the inclination of the face is almost zero degrees. Thus, at the step S 300  (shown in  FIG. 3 ), the direction of deformation is set in the horizontal direction of the original image IG 3 . Meanwhile, the person is positioned out of the middle and close to the left side in the horizontal direction of the original image IG 3 . Thus, at the step S 700 , the length of a reduction area SGb is set to be so wide as to include a human face FG 3  in the direction of deformation (horizontal). 
     After the directional deformation process is performed, as shown in  FIG. 12B , the reduction area SGb of a deformed image IM 3   b  is shorter than the reduction area SGb of the original image IG 3  in the horizontal direction. And an extension area EMb of the deformed image IM 3   b  is longer than the extension area EGb of the original image IG 3  in the horizontal direction. Thus, the deformed image IM 3   b  includes a human face FM 3   b  deformed to be slimmer than the human face FG 3  of the original image IG 3 . 
     As for the third embodiment, as described above, the width of the reduction area positioned in the middle of the direction of deformation is set in accordance with the position of the human face. Thus, if the human face is positioned around the middle, the original image is directionally deformed similarly to the first embodiment so that the human face is made slimmer than the face of the original image. If the face is positioned out of the middle, the reduction area is set to be wide. Thus, even if the face is positioned out of the middle of the image, the face can be deformed to be slimmer than the face of the original image. 
     According to the third embodiment, as described above, the width of the reduction area is set in accordance with the position of the face so that the face can be deformed to be slimmer than the face of the original image, even if the face is positioned out of the middle of the image. As the reduction area is set in accordance with the position of the face, the extension area is set across from an end portion of the reduction area to an end portion of the image. It may be said that a starting position of the extension area is arranged in accordance with the position of the face. 
     As for the third embodiment, the image is extended and reduced symmetrically with respect to the middle of the image similarly to the first embodiment. Thus, if the direction of deformation coincides with the direction of the line, pixels of the deformed image can be arranged before the arrangement of the pixels of the original image is changed, so that the memory size required for the directional deformation process can be reduced. 
     As for the third embodiment, the reduction area is set to be so wide as to include the face of the original image. Generally speaking, though, it is enough that the face is prevented from being extended in the direction of deformation. In that case, a non-deformed area that is neither reduced nor extended may be arranged next to and outside the reduction area, so that the non-deformed area may include the human face. In that case, the non-deformed area is arranged symmetrically with respect to the middle of the image so that the memory size required for the directional deformation process can be reduced. In a case where the facial shape of the deformed image produces no feeling of wrongness even if the extension area includes a portion of the face, the extension area may include the portion of the face. 
     D. Fourth Embodiment 
       FIG. 13  is a schematic block diagram of a printer  100   c  of the fourth embodiment. The printer  100   c  is different from the printer  100  of the first embodiment in that a facial shape correction processor  200   c  has a reduction area position setting unit  240   c . Other than that, the printer  100   c  equals the printer  100  of the first embodiment. 
       FIG. 14  is a flowchart of a facial shape correction print process of the fourth embodiment. The flowchart shown in  FIG. 14  is different from the flowchart of the facial shape correction print process of the first embodiment shown in  FIG. 3  in that a step S 700   c  is added between the steps S 300  and S 400 . 
     At the step S 700   c , the reduction area position setting unit  240   c  sets a position of the reduction area of the original image on the basis of the facial arrangement identified at the step S 200 . More specifically, the reduction area position setting unit  240   c  sets an area having a width calculated on the basis of the width of the face (erg., 2.5 times as wide as the face) centered with respect to the face in which the arrangement has been identified at the step S 200 . If the original image includes a plurality of faces, the reduction area is set for each of the faces. If inclinations of the plural faces are divided by a border of 45 degrees, no reduction area is set for one of the faces having a top-to-bottom direction close to the direction of deformation. 
       FIGS. 15A and 15B  illustrate the facial shape correction process in which the image IG 3  corresponding to the thumbnail image TN 3  shown in  FIG. 2  is corrected.  FIG. 15A  shows the original image IG 3  before the facial shape correction process.  FIG. 15B  shows a deformed image IM 3   c  that has been directionally deformed at the step S 400 . 
     As the inclination of the face in the image IG 3  shown in  FIG. 15A  is almost zero degrees, as described above, the direction of deformation is set in the horizontal direction of the image IG 3 . Meanwhile, the human face FG 3  is positioned out of the middle and off to the left side in the horizontal direction of the image IG 3 , i.e., the direction of deformation. Thus, at the step S 700   c , the reduction area is set to an area SGc centered with respect to the face FG 3 . At each of the left and right outsides of the reduction area SGc, extension areas EGLc and EGRc are arranged, respectively. 
     In a case where the center of the reduction area SGc is arranged close to the one end portion of the image, as described above, the pixels are rearranged from the center of the reduction area SGc towards the outside at the step S 424  shown in  FIG. 5 . In that case, the size of the corresponding pixel number table  420  corresponds to the number of the pixels between the center of the reduction area SGc and the other end portion of the image. 
     After the directional deformation process is performed, as shown in  FIG. 15B , the deformed image IM 3   c  has a reduction area SMc that is shorter than the reduction area SGc of the original image IG 3  in the horizontal direction, and extension areas EMLc and EMRc which are longer than the extension areas of the original image. Thus, the human face FM 3   c  of the deformed image IM 3   c  is deformed to be slimmer than the face FG 3  of the original image IG 3 . The reduction area SGc of the original image IG 3  is made narrower than in the case where the reduction area SGc is positioned in the middle of the image IG 3 . Thus, even in a case where the face FG 3  is positioned at the end portion of the image IG 3 , the whole extension area formed by combining the left and right extension areas EGLc and EGRc can be made wide enough. Thus, even if no blank is produced at the end portion of the deformed image IM 3   c  in the direction of deformation, the extension rates of the extension areas EGLc and EGRc can be set to be lower so that a chance of a feeling of wrongness of the corrected image caused by an increase of the extension rate can be reduced. 
     As for the fourth embodiment, as described above, the reduction area centered with respect to the face is set so that the face included in the reduction area is deformed to be slim. Thus, even if a person is positioned at an end portion of the image, the face can be deformed to be slim. The center of the reduction area can be set to the position of the face so that the extension area can be made wide enough. A chance of a feeling of wrongness of the corrected image caused by increase of the extension rate can be reduced, thereby. 
     As for the fourth embodiment, as shown in  FIG. 15 , the extension areas EGLc and EGRc are arranged at both end portions of the direction of deformation. Depending on the position of the face, though, the extension area may be arranged at one end portion. If a distance between the position of the face and the end of the image is shorter than a determined length (e.g., one twentieth of the length in the direction of deformation), no extension area may be positioned on the side of that end of the image. 
     E. Fifth Embodiment 
       FIG. 16  is a schematic block diagram of a printer  100   d  of the fifth embodiment. The printer  100   d  is different from the printer  100   c  of the fourth embodiment shown in  FIG. 13  in that a deformation direction setting unit  210   d  and a reduction area width setting unit  240   d  have different functions from those of the printer  100   c , and that a facial shape correction processor  200   d  has a face area deformation processor  250   d . Other than that, the printer  100   d  equals the printer  100   c  of the fourth embodiment. 
       FIG. 17  is a flowchart of a facial shape correction print process of the fifth embodiment. The flowchart shown in  FIG. 17  is different from the flowchart of the facial shape correction print process of the fourth embodiment shown in  FIG. 14  in that the two steps S 300  and S 700   c  are replaced by S 300   d  and S 700   d , respectively, and that a step S 800   d  is added between the steps S 200  and S 300   d.    
       FIG. 18  illustrates the facial shape correction process in which the image IG 1  corresponding to the thumbnail image TN 1  shown in  FIG. 2  is corrected.  FIG. 18A  shows the original image IG 1  before the facial shape correction process.  FIG. 18B  shows an image ID 1  that has been deformed in a face area deformation process (described later) at the step S 800   d .  FIG. 18C  shows a deformed image IF 1  directionally deformed at the step S 400 . 
     At the step S 800   d  shown in  FIG. 17 , the face area deformation processor  250   d  sets a face area to be deformed on the basis of the facial arrangement identified at the step S 200 . The face area deformation processor  250   d  makes correspondences between points in the face area after the deformation and points in the face area before the deformation (mapping) so as to deform the image in the face area. The face area deformation process using the mapping process will be described later. 
     As shown in  FIG. 18A , e.g., a face area TA is set to overlap the face FG 1 . Then, the shape of the face FG 1  in the original image IG 1  is deformed in the deformation process using the mapping process. As shown in  FIG. 18B , the deformation process makes cheeks of a human face FD 1  in the deformed image ID 1  slimmer than those of the face FG 1  in the original image IG 1 . 
     Contrary to the step S 300  of the fourth embodiment, if the inclination of the face is smaller than 45 degrees at the step S 300   d  shown in  FIG. 17 , the deformation direction setting unit  210   d  sets the direction of deformation to the vertical direction. Meanwhile, if the inclination of the face is greater than 45 degrees, the deformation direction setting unit  210   d  sets the direction of deformation to the horizontal direction. At the step S 700   d , then, the reduction area width setting unit  240   d  sets the position of the reduction area on the basis of the arrangement of the face area in the direction of deformation. 
     As shown in  FIG. 18B , the direction of deformation is set to the vertical direction of the image. A reduction area SD is set longer than the face area TA in the vertical direction (direction of deformation). The face area TA is arranged below the forehead of the person as described later. Thus, an upper end of the reduction area SD is arranged outside of an upper end of the face area TA. Then, extension areas EDU and EDD are arranged above and below the reduction area SD, respectively. 
     After the position of the reduction area SD is set at the step S 700   d  (shown in  FIG. 17 ), the reduction area and the extension areas arranged outside of the reduction area are directionally deformed at the step S 400 , so that the deformed image is produced. 
     As for the deformed image IF 1  that has been directionally deformed, as shown in  FIG. 18C , a reduction area SF is shorter than the reduction area SD of the image ID 1  in the vertical direction. Extension areas EFU and EFD are longer than the corresponding extension areas EDU and EDD of the image ID 1 , respectively, in the vertical direction. As described above, the face FD 1  deformed to be longer than is wide in the face area deformation process (step S 800   d ) is made shorter in the vertical direction in the directional deformation process (step S 400 ). Thus, even if the facial shape is corrected so much in the face area deformation process that the face is deformed to be yet longer than is wide, a ratio between lengths of the face in the top-to-bottom and left-to-right directions may be made nearly equal to the corresponding ratio of the original image IG 1 . Thus, even if an effect of the face area deformation process is enhanced, the face may be prevented from looking longer than is wide so that an image without a feeling of wrongness can be produced. 
     As for the fifth embodiment, as described above, even the face that has been deformed to be longer than is wide can be directionally deformed so that a length and width ratio of the face being close to that of the original face can be obtained. Thus, the image on which the face area deformation process has been performed can reduce a feeling of wrongness. 
     F. Facial Arrangement Identification 
       FIGS. 19A and 19B  shows an example of the facial arrangement identification process performed at the step S 200  shown in  FIG. 3 . In  FIG. 19 , an image IG 8  corresponding to a thumbnail image TN 8  shown in  FIG. 2  is processed. 
     For obtaining the facial arrangement, the facial arrangement identification unit  220  detects a rough position of the face from the image at first. In  FIG. 19A , e.g., an area FA representing the rough position of the face has been detected. The facial arrangement identification unit  220  detects the area FA (hereinafter may be called “detected face area FA”) by using a known method for detecting a face such as a pattern matching by using a template (refer to JP-A-2004-318204). The detected face area FA is a rectangular area including eyes, a nose and a mouth of the human face. 
     Next, the facial arrangement identification unit  220  identifies positions of left and right pupils by analyzing the detected face area FA. Then, the facial arrangement identification unit  220  identifies a central line DF as a line that characterizes the position and the top-to-bottom direction of the face. The line DF is perpendicular to a line EP that connects the positions of the left and right pupils, and passes a center between the left and right pupils. 
     G. Facial Area Deformation 
       FIGS. 20-23  illustrate an example of the face area deformation process performed at the step S 800   d  shown in  FIG. 17 . In  FIGS. 20-23 , the image IGB corresponding to the thumbnail image TN 8  shown in  FIG. 2  is processed similarly as in  FIGS. 19A and 19B . 
     As for the face area deformation process, the face area deformation processor  250   d  sets a mapping deformation area TA in which the deformation process using mapping is performed on the basis of the facial arrangement identified at the step S 200 . As shown in  FIG. 20 , the mapping deformation area TA is set as an area that covers between below the chin and above the eyebrows in the top-to-bottom direction. The mapping deformation area TA is set as an area that covers a whole outline of the face in the left-to-right direction. 
     In order to set the mapping deformation area TA, at first, the direction of the detected face area FA is arranged in accordance with the inclination of the face so that a face area MA is set. The face area MA in which the inclination has been arranged is extended in directions upper and lower than the line EP connecting the pupils and leftward and rightward directions of the central line DF, at a determined magnification for each of the above directions, so that the mapping deformation area TA is set. 
     The mapping deformation area TA is divided into a plurality of sub-areas as shown in  FIG. 21 . Then, as shown in  FIG. 22 , a mapping process is performed in such a way that lattice points before the deformation shown by white dots move to lattice points after the deformation shown by white dots. By setting values of pixels on the basis of the mapping process, as shown in  FIG. 23 , the image in the mapping deformation area TA is deformed and an image ID 8  in which the face has been deformed to be slim is produced by the face area deformation process. 
     In general, the face area deformation process may be another type of deformation process as long as the image is deformed in a deformation area. For example, an image in the middle of the deformation area may be reduced along the line EP, and an image at an end portion of the deformation area may be extended along the line EP. 
     H. Modifications 
     The invention is not limited to the examples or the embodiments described above, and may be implemented in various forms, such as following modifications. 
     H1. First Modification 
     Although the extension area of the third to fifth embodiments described above are extended at a constant extension rate in the direction of deformation, the extension rate can be changed in accordance with the distance from the reduction area, similarly to the second embodiment. 
     H2. Second Modification 
     Although being applied to the deformation process of a facial shape as for the above embodiments, the invention can be applied to a deformation process different from the deformation process of the facial shape. The invention can be generally applied to a deformation process of an object included in an image. 
     H3. Third Modification 
     Although being applied to the printer as for the above embodiments, the invention can be applied to any device as long as it is configured to perform a directional deformation process on an original image. The invention can be applied to, e.g., a personal computer or a digital still camera as long as it is configured to perform an image deformation process. 
     H4. Fourth Embodiment 
     As for the above embodiments, some portions implemented by hardware may be implemented by software, and vice versa. 
     The present application claims the priority based on a Japanese Patent Application No. 2008-076268 filed on Mar. 24, 2008, the disclosure of which is hereby incorporated by reference in its entirety.