Image processing apparatus, image processing method, image processing program, and storage medium

Abstract

There is disclosed an image processing apparatus which applies an adjusting process to an image that includes a pixel to be processed. The image processing apparatus extracts an image area with a predetermined size including the pixel to be processed. The apparatus calculates a variation associated with the pixel to be processed from signal values of pixels included in the image area. The apparatus calculates a variation time count in the image area from the signal values of the pixels included in the image area. The apparatus calculates adjusting levels Fz 1, Fz 2 , and Fe from the variation time count and the variation using a definition unit which defines correspondence among the variation time count, the variation, and the adjusting levels, and applies an adjusting process to a signal value of the pixel to be processed by the calculated adjusting levels. Note that the definition unit defines the correspondence so that the adjusting levels Fz 1, Fz 2 , and Fe progressively change in accordance with different variation time counts or different variations.

What is claimed is: 
     
       1. An image processing apparatus, which applies an adjusting process to an image that includes a pixel to be processed, said apparatus comprising:
 an extraction unit adapted to extract an image area with a predetermined size including the pixel to be processed; 
 a variation calculation unit adapted to calculate a variation with respect to the pixel to be processed from signal values of pixels included in the image area; 
 a variation time count calculation unit adapted to calculate a variation time count with respect to the pixel to be processed from the signal values of the pixels included in the image area; 
 a definition unit adapted to define correspondence among the variation time count, the variation, and an adjusting level; and 
 an adjusting unit adapted to calculate the adjusting level from the variation time count and the variation using said definition unit, and to apply an adjusting process to a signal value of the pixel to be processed by the calculated adjusting level, 
 wherein said definition unit defines the correspondence so that the adjusting level progressively changes in accordance with different variation time counts or different variations. 
 
     
     
       2. The apparatus according to  claim 1 , wherein said definition unit defines the correspondence within at least a part of a value range that the variation time count can assume, so that the adjusting level progressively changes according to the variation time count. 
     
     
       3. The apparatus according to  claim 1 , wherein said definition unit defines the correspondence within at least a part of a value range that the variation can assume, so that the adjusting level progressively changes according to the variation. 
     
     
       4. The apparatus according to  claim 1 , wherein when the variation time count is smaller than a first threshold, said definition unit defines the adjusting level to be a maximum value,
 when the variation time count is larger than a second threshold which is larger than the first threshold, said definition unit defines the adjusting level to be a minimum value, and 
 said definition unit defines so that the adjusting level progressively changes from the maximum value to the minimum value as the variation time count changes from the first threshold to the second threshold. 
 
     
     
       5. The apparatus according to  claim 4 , wherein the maximum value and the minimum value have different signs. 
     
     
       6. The apparatus according to  claim 1 , wherein when the variation is smaller than a third threshold, said definition unit defines the adjusting level to be a minimum value,
 when the variation is larger than a fourth threshold which is larger than the third threshold, said definition unit defines the adjusting level to be a maximum value, and 
 said definition unit defines so that the adjusting level progressively changes from the minimum value to the maximum value as the variation changes from the third threshold to the fourth threshold. 
 
     
     
       7. The apparatus according to  claim 1 , wherein said variation calculation unit calculates the variation from signal values of a plurality of pixels which line up on an edge direction in the image area. 
     
     
       8. The apparatus according to  claim 7 , wherein said variation calculation unit compares differences between signal values of pixel sequences in a plurality of directions including the pixel to be processed in the image area, and defines a direction with the maximum difference as the edge direction. 
     
     
       9. The apparatus according to  claim 1 , wherein said variation time count calculation unit calculates the variation time count from signal values of pixels which line up on an edge direction in the image area. 
     
     
       10. The apparatus according to  claim 1 , wherein said variation calculation unit calculates, as the variation, a maximum absolute value of primary derivatives of signal values of a plurality of pixels, which line up on an edge direction in the image area. 
     
     
       11. The apparatus according to  claim 1 , wherein said adjusting unit executes, as the adjusting process, at least one of an edge emphasis process, a smoothing process, a substitution process, and an achromatization process, and
 said definition unit defines, as the adjusting level, at least one of an edge emphasis amount, a smoothing amount, a substitute amount, and an achromatization amount. 
 
     
     
       12. The apparatus according to  claim 1 , wherein said definition unit defines correspondence among the variation time count, and a first adjusting level and a second adjusting level, and defines correspondence between the variation and a third adjusting level,
 said adjusting unit executes a filter process of the pixel to be processed using the first adjusting level, the second adjusting level, and the third adjusting level. 
 
     
     
       13. The apparatus according to  claim 12 , wherein when the variation time count is smaller than a fifth threshold, said definition unit defines the first adjusting level to be a maximum value,
 when the variation time count is larger than a sixth threshold which is larger than the fifth threshold, said definition unit defines the first adjusting level to be a minimum value, 
 said definition unit defines so that the first adjusting level progressively changes from the maximum value to the minimum value as the variation time count changes from the fifth threshold to the sixth threshold, 
 when the variation time count is smaller than a seventh threshold, said definition unit defines the second adjusting level to be a minimum value, 
 when the variation time count is larger than an eighth threshold which is larger than the seventh threshold, said definition unit defines the second adjusting level to be a maximum value, and 
 said definition unit defines so that the second adjusting level progressively changes from the minimum value to the maximum value as the variation time count changes from the seventh threshold to the eighth threshold. 
 
     
     
       14. The apparatus according to  claim 1 , further comprising a variation acceleration calculation unit adapted to calculate a variation acceleration associated with the image area from signal values of pixels included in the image area,
 wherein said definition unit defines correspondence between the variation acceleration and a fourth adjusting level, 
 said definition unit defines correspondence between the variation time count and a fifth adjusting level, 
 said definition unit defines correspondence between the variation and a sixth adjusting level, and 
 said adjusting unit executes a substitution process of the pixel to be processed using the fourth adjusting level, the fifth adjusting level, and the sixth adjusting level. 
 
     
     
       15. The apparatus according to  claim 14 , wherein when the variation acceleration is smaller than a ninth threshold, said definition unit defines the fourth adjusting level to be a minimum value,
 when the variation acceleration is larger than a 10th threshold which is larger than the ninth threshold, said definition unit defines the fourth adjusting level to be a maximum value, and 
 said definition unit defines so that the fourth adjusting level progressively changes from the minimum value to the maximum value as the variation acceleration changes from the ninth threshold to the 10th threshold. 
 
     
     
       16. The apparatus according to  claim 1 , further comprising a saturation calculation unit adapted to calculate a saturation associated with the image area from signal values of pixels included in the image area,
 wherein said definition unit defines correspondence between the saturation and a seventh adjusting level, 
 said definition unit defines correspondence between the variation time count and an eighth adjusting level, 
 said definition unit defines correspondence between the variation and a ninth adjusting level, and 
 said adjusting unit executes a substitution process of the pixel to be processed using the seventh adjusting level, the eighth adjusting level, and the ninth adjusting level. 
 
     
     
       17. The apparatus according to  claim 16 , wherein when the saturation is smaller than an 11th threshold, said definition unit defines the seventh adjusting level to be a maximum value,
 when the saturation is larger than a 12th threshold which is larger than the 11th threshold, said definition unit defines the seventh adjusting level to be a minimum value, and 
 said definition unit defines so that the seventh adjusting level progressively changes from the maximum value to the minimum value as the saturation changes from the 11th threshold to the 12th threshold. 
 
     
     
       18. An image processing method, which applies an adjusting process to an image that includes a pixel to be processed, said method comprising the steps of:
 using an extracting unit to extract an image area with a predetermined size including the pixel to be processed; 
 using a variation calculating unit to calculate a variation with respect to the pixel to be processed from signal values of pixels included in the image area; 
 using a variation time count calculating unit to calculate a variation time count with respect to the pixel to be processed from the signal values of the pixels included in the image area; and 
 using an adjusting level calculating unit to calculate an adjusting level from the variation time count and the variation using a definition unit which defines correspondence among the variation time count, the variation, and the adjusting level, and applying an adjusting process to a signal value of the pixel to be processed by the calculated adjusting level, 
 wherein the definition unit defines the correspondence so that the adjusting level progressively changes in accordance with different variation time counts or different variations. 
 
     
     
       19. A non-transitory computer-readable storage medium storing an image processing program, which causes an image processing apparatus to apply an adjusting process to an image that includes a pixel to be processed,
 the image processing apparatus executing the image processing program to implement the steps of: 
 extracting an image area with a predetermined size including the pixel to be processed; 
 calculating a variation with respect to the pixel to be processed from signal values of pixels included in the image area; 
 calculating a variation time count with respect to the pixel to be processed from the signal values of the pixels included in the image area; and 
 calculating an adjusting level from the variation time count and the variation using a definition unit which defines correspondence among the variation time count, the variation, and the adjusting level, and applying an adjusting process to a signal value of the pixel to be processed by the calculated adjusting level, 
 wherein the definition unit defines the correspondence so that the adjusting level progressively changes in accordance with different variation time counts or different variations. 
 
     
     
       20. An image processing apparatus which adjusts a pixel of an image, the apparatus comprising:
 a setting unit configured to set an adjusting amount to adjust a pixel value of a target pixel to be adjusted in a predetermined region of the image based on a variation count such that the adjusting amount is set as at least one of a first amount, a second amount different from the first amount, or a third amount between the first amount and the second amount according to the variation count,   wherein the variation count is a count of inversion of variance tendency of a variation amount, and the variation amount is a pixel value difference between pixel values of pixels of a plurality of pixels that are aligned in a line through the target pixel; and   an adjusting unit configured to adjust the pixel value of the target pixel with the adjusting amount set by the setting unit.   
     
     
       21. The apparatus according to claim 20, wherein the setting unit sets the adjusting amount further based on the variation amount. 
     
     
       22. The apparatus according to claim 20, wherein the variation amount is a pixel value difference between two pixel values that are aligned with a pixel interleaved between the two pixels. 
     
     
       23. The apparatus according to claim 20,
 wherein the setting unit further sets an adjusting level which is a coefficient for determining the adjusting amount, and   wherein the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count.   
     
     
       24. The apparatus according to claim 23, wherein the third level of the adjusting level gradually changes from the first level to the second level according to at least part of an available range of the variation count. 
     
     
       25. The apparatus according to claim 23,
 wherein the setting unit sets each of the first, second, and third levels according to at least part of an available range of the variation count, and   wherein the third level of the adjusting level gradually changes from the first level to the second level.   
     
     
       26. The apparatus according to claim 20, wherein the adjusting unit adjusts the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       27. The apparatus according to claim 24, wherein the adjusting unit adjusts the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       28. The apparatus according to claim 26, wherein, in a case where the adjusting unit adjusts the pixel value of the target pixel for the edge emphasis process, the setting unit (i) sets the adjusting amount as the first amount if the variation count is less than a first threshold, (ii) sets the adjusting amount as the second amount which is smaller than the first amount if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) sets the adjusting amount as the third amount if the variation count is between the first threshold and the second threshold. 
     
     
       29. The apparatus according to claim 28, wherein the setting unit (i) sets the adjusting amount as the second amount if the variation count is less than a third threshold, (ii) sets the adjusting amount as the first amount if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) sets the adjusting amount as the third amount if the variation count is between the third threshold and the fourth threshold. 
     
     
       30. The apparatus according to claim 29, wherein the variation amount is a pixel value difference between pixels in an edge direction in the predetermined region of the image. 
     
     
       31. The apparatus according to claim 29, wherein the variation count is a count of inversion of variance tendency of the variation amount between pixels in an edge direction in the predetermined region of the image. 
     
     
       32. The apparatus according to claim 30, wherein the edge direction is a direction of a line including a variation amount which has a largest pixel value difference of all lines in the predetermined region of the image. 
     
     
       33. The apparatus according to claim 29, wherein the variation amount is an absolute value of a first derivation of pixels in an edge direction in the predetermined of the image. 
     
     
       34. The apparatus according to claim 29, wherein the adjusting unit adjusts the pixel value of the target pixel by a filtering process for the edge emphasis process. 
     
     
       35. The apparatus according to claim 28,
 wherein the setting unit further sets an adjusting level which is a coefficient for determining the adjusting amount, and the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count, and   wherein the setting unit (i) sets the adjusting level as the first level if the variation count is less than a first threshold, (ii) sets the adjusting level as the second level which is smaller than the first level if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) sets the adjusting amount as the third level if the variation count is between the first threshold and the second threshold.   
     
     
       36. The apparatus according to claim 35, wherein the setting unit (i) sets the adjusting level as the second level if the variation count is less than a third threshold, (ii) sets the adjusting level as the first level if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) sets the adjusting level as the third level if the variation count is between the third threshold and the fourth threshold. 
     
     
       37. The apparatus according to claim 20, wherein the variation count is calculated in a plurality of lines through the target pixel. 
     
     
       38. The apparatus according to claim 20, wherein the variation count is a count of change of a sign of a variation amount. 
     
     
       39. The apparatus according to claim 38, wherein the variation count is calculated with a pixel determined in turn in the plurality of pixels that are aligned in the line. 
     
     
       40. The apparatus according to claim 20, further comprising:
 a generating unit configured to generate image data based on the pixel value adjusted by the adjusting unit; and   a printing unit configured to print the image based on the image data by discharging ink from a printhead.   
     
     
       41. The apparatus according to claim 40, further comprising a reading unit configured to read the image. 
     
     
       42. A method for an image processing apparatus which adjusts a pixel of an image, the method comprising:
 a setting step of setting an adjusting amount to adjust a pixel value of a target pixel to be adjusted in a predetermined region of the image based on a variation count such that the adjusting amount is set as at least one of a first amount, a second amount different from the first amount, or a third amount between the first amount and the second amount according to the variation count,   wherein the variation count is a count of inversion of variance tendency of a variation amount, and the variation amount is a pixel value difference between pixel values of pixels of a plurality of pixels that are aligned in a line through the target pixel; and   an adjusting step of adjusting the pixel value of the target pixel with the adjusting amount set in the setting step.   
     
     
       43. The method according to claim 42, wherein the setting step includes setting the adjusting amount further based on the variation amount. 
     
     
       44. The method according to claim 42, wherein the variation amount is a pixel value difference between two pixel values that are aligned with a pixel interleaved between the two pixels. 
     
     
       45. The method according to claim 42,
 wherein the setting step includes setting an adjusting level which is a coefficient for determining the adjusting amount, and   wherein the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count.   
     
     
       46. The method according to claim 45, wherein the third level of the adjusting level gradually changes from the first level to the second level according to at least part of an available range of the variation count. 
     
     
       47. The method according to claim 45,
 wherein the setting step includes setting each of the first, second, and third levels according to at least part of an available range of the variation count, and   wherein the third level of the adjusting level gradually changes from the first level to the second level.   
     
     
       48. The method according to 42, wherein the adjusting step includes adjusting the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       49. The method according to claim 46, wherein the adjusting step includes adjusting the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       50. The method according to claim 48, wherein, in a case where the adjusting step includes adjusting the pixel value of the target pixel for the edge emphasis process, the setting step includes (i) setting the adjusting amount as the first amount if the variation count is less than a first threshold, (ii) setting the adjusting amount as the second amount which is smaller than the first amount if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) setting the adjusting amount as the third amount if the variation count is between the first threshold and the second threshold. 
     
     
       51. The method according to claim 50 wherein the setting step includes (i) setting the adjusting amount as the second amount if the variation count is less than a third threshold, (ii) setting the adjusting amount as the first amount if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) setting the adjusting amount as the third amount if the variation count is between the third threshold and the fourth threshold. 
     
     
       52. The method according to claim 51, wherein the variation amount is a pixel value difference between pixels in an edge direction in the predetermined region of the image. 
     
     
       53. The method according to claim 51, wherein the variation count is a count of inversion of variance tendency of the variation amount between pixels in an edge direction in the predetermined region of the image. 
     
     
       54. The method according to claim 52, wherein the edge direction is a direction of a line including a variation amount which has a largest pixel value difference of all lines in the predetermined region of the image. 
     
     
       55. The method according to claim 51, wherein the variation amount is an absolute value of a first derivation of pixels in an edge direction in the predetermined of the image. 
     
     
       56. The method according to claim 51, wherein the adjusting step includes adjusting the pixel value of the target pixel by a filtering process for the edge emphasis process. 
     
     
       57. The method according to claim 50,
 wherein the setting step includes setting an adjusting level which is a coefficient for determining the adjusting amount, and the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count, and   wherein the setting step includes (i) setting the adjusting level as the first level if the variation count is less than a first threshold, (ii) setting the adjusting level as the second level which is smaller than the first level if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) setting the adjusting amount as the third level if the variation count is between the first threshold and the second threshold.   
     
     
       58. The method according to claim 57, wherein the setting step includes (i) setting the adjusting level as the second level if the variation count is less than a third threshold, (ii) setting the adjusting level as the first level if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) setting the adjusting level as the third level if the variation count is between the third threshold and the fourth threshold. 
     
     
       59. The method according to claim 42, wherein the variation count is calculated in a plurality of lines through the target pixel. 
     
     
       60. The method according to claim 42, wherein the variation count is a count of change of a sign of a variation amount. 
     
     
       61. The method according to claim 50, wherein the variation count is calculated with a pixel determined in turn in the plurality of pixels that are aligned in the line. 
     
     
       62. The method according to claim 42, further comprising:
 a generating step of generating image data based on the pixel value adjusted in the adjusting step; and   a printing step of printing the image based on the image data by discharging ink from a printhead.   
     
     
       63. The method according to claim 62, further comprising a reading step of reading the image. 
     
     
       64. An image processing apparatus which adjusts a pixel of an image, the apparatus comprising:
 a setting unit configured to set an adjusting amount to adjust a pixel value of a target pixel to be adjusted in a predetermined region of the image, wherein the predetermined region has a plurality of pixels, including the target pixel, that are arranged in a predetermined direction, and   an adjusting unit configured to adjust the pixel value of the target pixel with the adjusting amount set by the setting unit,   wherein the setting unit   obtains a variation count relating to the target pixel based on a count of inversion of variance tendency of a pixel value difference between each set of vicinal two pixels of the plurality of pixels in the predetermined direction, wherein positions of sets of vicinal two pixels are shifted each other in the predetermined direction,   sets the adjusting amount based on the variation count relating to the target pixel to a first amount in a case where the variation count is a first variation count,   sets the adjusting amount based on the variation count relating to the target pixel to a second amount different from the first amount in a case where the variation count is a second variation count different from the first variation count, and   sets the adjusting amount based on the variation count relating to the target pixel to a third amount between the first amount and the second amount in a case where the variation count is a third variation count between the first variation count and the second variation count.   
     
     
       65. The apparatus according to claim 64, wherein the setting unit further obtains, as a variation amount relating to the target pixel, one pixel value difference of a plurality of pixel value differences, and
 the setting unit sets the adjusting amount further based on the variation amount relating to the target pixel.   
     
     
       66. The apparatus according to claim 65, wherein the setting unit obtains the variation amount relating to the target pixel based on two pixels adjacent to the target pixel in the predetermined direction. 
     
     
       67. The apparatus according to claim 65, wherein the variation amount is a maximum absolute value of a plurality of pixel value differences in four directions including the target pixel. 
     
     
       68. The apparatus according to claim 64, wherein the variation count is a sum of counts of inversion of variance tendency in four directions including the target pixel. 
     
     
       69. The apparatus according to claim 64,
 wherein the setting unit further sets an adjusting level which is a coefficient for determining the adjusting amount, and   wherein the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count.   
     
     
       70. The apparatus according to claim 69, wherein the third level of the adjusting level gradually changes from the first level to the second level according to at least part of an available range of the variation count. 
     
     
       71. The apparatus according to claim 69,
 wherein the setting unit sets each of the first, second, and third levels according to at least part of an available range of the variation count, and   wherein the third level of the adjusting level gradually changes from the first level to the second level.   
     
     
       72. The apparatus according to claim 64, wherein the adjusting unit adjusts the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       73. The apparatus according to claim 70, wherein the adjusting unit adjusts the pixel value of the target pixel for at least one of an edge emphasis process, a smoothing process, a substitution process, or an achromatization process. 
     
     
       74. The apparatus according to claim 72, wherein, in a case where the adjusting unit adjusts the pixel value of the target pixel for the edge emphasis process, the setting unit (i) sets the adjusting amount as the first amount if the variation count is less than a first threshold, (ii) sets the adjusting amount as the second amount which is smaller than the first amount if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) sets the adjusting amount as the third amount if the variation count is between the first threshold and the second threshold. 
     
     
       75. The apparatus according to claim 74, wherein the setting unit (i) sets the adjusting amount as the second amount if the variation count is less than a third threshold, (ii) sets the adjusting amount as the first amount if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) sets the adjusting amount as the third amount if the variation count is between the third threshold and the fourth threshold. 
     
     
       76. The apparatus according to claim 75, wherein the variation amount is a pixel value difference between pixels in an edge direction in the predetermined region of the image. 
     
     
       77. The apparatus according to claim 75, wherein the variation count is a count of inversion of variance tendency of the variation amount between pixels in an edge direction in the predetermined region of the image. 
     
     
       78. The apparatus according to claim 74, wherein the edge direction is a direction of a line including a variation amount which has a largest pixel value difference of all lines in the predetermined region of the image. 
     
     
       79. The apparatus according to claim 75, wherein the variation amount is an absolute value of a first derivation of pixels in an edge direction in the predetermined of the image. 
     
     
       80. The apparatus according to claim 75, wherein the adjusting unit adjusts the pixel value of the target pixel by a filtering process for the edge emphasis process. 
     
     
       81. The apparatus according to claim 74,
 wherein the setting unit further sets an adjusting level which is a coefficient for determining the adjusting amount, and the adjusting level is set as at least one of a first level, a second level different from the first level, or a third level between the first level and the second level according to the variation count, and   wherein the setting unit (i) sets the adjusting level as the first level if the variation count is less than a first threshold, (ii) sets the adjusting level as the second level which is smaller than the first level if the variation count is greater than a second threshold which is greater than the first threshold, and (iii) sets the adjusting amount as the third level if the variation count is between the first threshold and the second threshold.   
     
     
       82. The apparatus according to claim 81, wherein the setting unit (i) sets the adjusting level as the second level if the variation count is less than a third threshold, (ii) sets the adjusting level as the first level if the variation count is greater than a fourth threshold which is greater than the third threshold, and (iii) sets the adjusting level as the third level if the variation count is between the third threshold and the fourth threshold. 
     
     
       83. The apparatus according to claim 64, further comprising:
 a generating unit configured to generate image data based on the pixel value adjusted by the adjusting unit; and   a printing unit configured to print the image based on the image data by discharging ink from a print head.   
     
     
       84. The apparatus according to claim 64, further comprising a reading unit configured to read the image.