IMAGE CORRECTING APPARATUS AND METHOD, AND IMAGE CORRECTING PROGRAM, AND LOOK-UP TABLE CREATING APPARATUS AND METHOD, AND LOOK-UP TABLE CREATING PROGRAM

• US 20090136152A1
• Filed: 01/30/2009
• Published: 05/28/2009
• Est. Priority Date: 06/17/2004
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kameyama, Hirokazu
• Granted Patent: US 8,035,871 B2
• Time in Patent Office: Days
• US Class Current: 382/275
• CPC Class Codes: H04N 1/60 Colour correction or control H04N1/54 takes precedence

Abstract

A bright luminance value, a dark luminance value, and an average luminance value relating to a face image portion included in an image represented by fed image data are calculated in calculating circuits. Further, a target bright luminance value and a target dark luminance value are calculated in a calculating circuit on the basis of a target average luminance value and a dynamic range that are inputted from an input device and the calculated bright luminance value, dark luminance value, and average luminance value. Interpolation processing based on a correspondence between the calculated bright luminance value, dark luminance value, and average luminance value relating to the face image portion and the target bright luminance value, the target dark luminance value, and the target average luminance value respectively corresponding thereto is performed in a corrected value calculating circuit, to create a look-up table.

Claims

1-16. -16. (canceled)

17. An image correcting apparatus comprising:

representative luminance value calculation means for calculating a representative luminance value in a particular image included in an image represented by fed image data;

noise amount calculation means for calculating a noise amount included in particular image data representing the particular image;

target luminance value determination means for determining a target luminance value depending on the noise amount calculated by the noise amount calculation means;

means for producing data representing a luminance conversion straight line or a luminance conversion curve such that the represented luminance value calculated by the representative luminance value calculation means is corrected to the target luminance value determined by the target luminance value determination means; and

luminance correction means for correcting the luminance of at least the particular image data representing the particular image on the basis of the produced data representing the luminance conversion straight line or the luminance conversion curve.

18. The image correcting apparatus according to claim 17, comprising

desired target luminance value input means for accepting input of a desired target luminance value, and

predicted noise amount calculation means for calculating a predicted noise amount that may be included in the particular image data after luminance correction on the basis of the representative luminance value calculated by the representative luminance value calculation means, the desired target luminance value inputted by the target luminance value input means, and the noise amount calculated by the noise amount calculation means,

the target luminance value determination means determining the target luminance value depending on the predicted noise amount calculated by the predicted noise amount calculation means.

19. The image correcting apparatus according to claim 17, wherein

the target luminance value determination means determines, on the basis of an allowable noise amount for noise that may be included in the particular image data after luminance correction and the calculated noise amount or the calculated predicted noise amount, that are previously set or inputted, the target luminance value such that the noise amount or the predicted noise amount is not more than the allowable noise amount.

20. The image correcting apparatus according to claim 18, wherein

the target luminance value determination means

determines the desirable target luminance value inputted from the desirable target luminance value input means as the target luminance value when the calculated predicted noise amount is not more than the allowable noise amount, and

calculates, when the calculated predicted noise amount exceeds the allowable noise amount, such a new target luminance value that the predicted noise amount is the same as the allowable noise amount on the basis of the representative luminance value, the allowable noise amount, and the noise amount, and determines the calculated new target luminance value as the target luminance value.

21. The image correcting apparatus according to claim 17, wherein said particular image is an image representing the face of a character.

22. The image correcting apparatus according to claim 17, wherein the representative luminance value is the average luminance value in the particular image.

23. An image correcting method comprising the steps of:

calculating a representative luminance value in a particular image included in an image represented by fed image data;

calculating a noise amount included in particular image data representing the particular image;

determining a target luminance value depending on the calculated noise amount;

producing data representing a luminance conversion straight line or a luminance conversion curve such that the calculated representative luminance value is corrected to the determined target luminance value; and

correcting the luminance of at least the particular image data representing the particular image on the basis of the produced data representing the luminance conversion straight line or the luminance conversion curve.

24. A program for causing a computer to carry out the procedures for:

calculating a representative luminance value in a particular image included in an image represented by fed image data;

calculating a noise amount included in particular image data representing the particular image;

determining a target luminance value depending on the calculated noise amount;

producing data representing a luminance conversion straight line or a luminance conversion curve such that the calculated representative luminance value is corrected to the determined target luminance value; and

correcting the luminance of at least the particular image data representing the particular image on the basis of the produced data representing the luminance conversion straight line or the luminance conversion curve.