Image reproduction apparatus and method

• US 6,201,893 B1
• Filed: 09/27/1995
• Issued: 03/13/2001
• Est. Priority Date: 09/28/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ikeda, Eiichiro, Udagawa, Yoshiro, Shiraiwa, Yoshinobu
• Primary Examiner(s): Chen, WenPeng
• Application Number:
  US08/534,338
• Time in Patent Office: 1,994 Days
• Field of Search: 382/164, 382/165, 382/166, 382/167, 382/220, 382/274, 382/218, 382/162, 382/305, 358/518, 358/520, 358/515, 358/516, 358/523, 348/223, 348/225, 348/655
• US Class Current: 382/167
• CPC Class Codes: H04N 1/4074 using histograms
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

In an image reproduction apparatus for converting an image into an image signal that can be visibly output, and performing image reproduction processing for the image signal, at least two image signals are selected and designated from a plurality of image signals picked up by image pickup means, and predetermined information (e.g., light source information such as the color temperature, the chromaticity of a light source, or the like) is extracted by analyzing the selected and designated image signals. The image reproduction parameters used in the image reproduction processing are determined on the basis of the extracted information. In this case, the parameters are corrected by repeating the processing the number of times corresponding to the number of selected and designated image signals, thereby finally determining the image reproduction parameters.

Claims

1. An image reproduction apparatus for converting an image into a scene of an image signal, and performing image reproduction processing on the scene of the image signal, comprising:

means for reproducing a plurality of scenes of image signals picked up by image pickup means from a recording medium so that each scene of image signals can be visibly reproduced;

means for designating at least two scenes of image signals from among the plurality of reproduced scenes of image signals based on predetermined conditions of images;

means for extracting correction information by analyzing the designated scenes of image signals; and

correction means for correcting image reproduction parameters to be used in the image reproduction processing on the basis of the extracted correction information.

2. The apparatus according to claim 1, further comprising:

means for discriminating if the designated scenes of image signals are present in a white area which is determined in advance; and

means for, when the scenes of the image signals are present in the white area, obtaining color component data on the basis of the scenes of the image signals,

wherein said correction means corrects the image reproduction parameters on the basis of the color component data.

3. The apparatus according to claim 1, further comprising:

means for calculating a frequency distribution of luminance levels between the designated scenes of image signals; and

means for obtaining luminance-distribution-smoothing processing using the frequency distribution of luminance levels, and

wherein said correction means corrects the image reproduction parameters on the basis of a result of the luminance distribution smoothing processing.

4. The apparatus according to claim 1, wherein said correction means performs processing for correcting the image reproduction parameters the number of times which matches the number of designated scenes of image signals.

5. The apparatus according to claim 1, wherein said correction means performs processing for correcting the image reproduction parameters a predetermined number of times.

6. The apparatus according to claim 5, wherein the predetermined number of times is the number of designated scenes of image signals present in a white area which is determined in advance.

7. The apparatus according to claim 1, wherein said correction means corrects the image reproduction parameters on the basis of specific scenes of image signals of the designated scenes of image signals.

8. The apparatus according to claim 1, further comprising:

means for weighting the designated scenes of image signals,

wherein said correction means corrects the image reproduction parameters on the basis of the weighted scenes of image signals.

9. The apparatus according to claim 1, wherein the image reproduction parameters include at least color temperature information, gradation information, luminance information, and white balance coefficients.

10. An image reproduction method for converting an image into a scene of an image signal, and performing image reproduction processing on the scene of the image signal, comprising the steps of:

reproducing a plurality of scenes of image signals picked up by image pickup means from a recording medium so that each scene of image signals can be visibly reproduced;

designating at least two scenes of image signals from among the plurality of reproduced scenes of image signals based on predetermined conditions;

extracting correction information by analyzing the designated scenes of image signals; and

correcting image reproduction parameters used in the image reproduction processing, on the basis of the extracted correction information.

11. An image reproduction apparatus for converting an image into a scene of an image signal, and performing image reproduction processing on the scene of the image signal, comprising:

means for reproducing a plurality of scenes of image signals picked up by image pickup means from a recording medium so that each scene of image signals can be visibly reproduced;

means for selecting at least two scenes of image signals from among the plurality of reproduced scenes of image signals based on predetermined conditions;

means for selecting an image-reproduction-parameter group to be used in the image reproduction processing which corresponds to the scenes of the image signals; and

processing means for performing the image reproduction processing on the selected scenes of image signals in accordance with parameters in the image-reproduction-parameter group,

wherein said processing means performs the image reproduction processing using the image-reproduction-parameter group common to the selected scenes of image signals the number of times which matches the number of selected scenes of image signals.

12. The apparatus according to claim 11, wherein the parameters constituting the image-reproduction-parameter group include at least color temperature information, gradation information, luminance information, and white balance coefficients.

13. An image reproduction method for converting an image into a scene of an image signal, and performing image reproduction processing on the scene of the image signal, comprising:

the step of reproducing a plurality of scenes of image signals picked up by image pickup means from a recording medium so that each scene of image signals can be visibly reproduced;

the step of selecting at least two scenes of image signals from among the plurality of reproduced scenes of image signals based on predetermined conditions;

the step of selecting an image-reproduction-parameter group to be used in the image reproduction processing which corresponds to the scenes of the image signals; and

the processing step of performing the image reproduction processing on the selected scenes of image signals in accordance with parameters in the image-reproduction-parameter group,

wherein the processing step includes the step of performing the image reproduction processing using the image-reproduction-parameter group common to the selected scenes of image signals the number of times which matches the number of selected scenes of image signals.