JP2002247361A5

JP2002247361A5 -

Info

Publication number: JP2002247361A5
Application number: JP2001037763A
Authority: JP
Filing date: 2001-02-14
Publication date: 2005-09-02
Anticipated expiration: 2021-02-14

Claims

An image processing apparatus for correcting the image data to the image data of the optimum exposure condition, and a scene determining means for determining whether data or other data of the data or nighttime scene shot backlit scene for the image data, the scene discrimination wherein when it is determined that the data of the data or the nighttime scene shot backlit scene, and the object exposure determination means for determining an exposure condition by removing the background data from the image data, the determination result of the object exposure determination unit by means a correction unit which performs different image correction based on,
An image processing apparatus comprising:

The scene determination means is a distribution means for distributing each pixel of the image data to one of a plurality of brightness levels divided into at least two stages according to the brightness of each pixel ;
First appearance ratio calculating means for obtaining an appearance ratio of pixels distributed to the darkest part level or the brightest part level;
The occupied in the number of pixels allocated to darkest level or the lightest unit level, comprising a second appearance ratio calculating means for calculating a ratio of the number of pixels belonging to a predetermined region of the image edge portion,
The image processing apparatus according to claim 1, wherein the performing scene discrimination from the calculated value of the second appearance ratio calculating means and calculating values of the first appearance ratio calculating means.

The scene determination means is a distribution means for distributing each pixel of the image data to any one of a plurality of brightness levels divided into at least two stages according to the brightness of each pixel;
  First appearance ratio calculating means for obtaining an appearance ratio of pixels distributed to the darkest part level or the brightest part level;
  A second appearance ratio calculating means for obtaining a ratio of the number of pixels belonging to a predetermined region at the edge of the image in the number of pixels allocated to the darkest part level or the brightest part level;
  Pixels assigned to the darkest part level by the first appearance ratio calculating means have an appearance ratio of the pixels assigned to the darkest part level equal to or higher than a first threshold value, and assigned to the darkest part level by the second appearance ratio calculating means If the ratio of the number of pixels belonging to the predetermined region at the edge of the image is greater than or equal to the second threshold,
  The appearance ratio of the pixels distributed to the brightest part level by the first appearance ratio calculation means is a third threshold or more,
  And the sum of the appearance ratio of the pixels distributed to the darkest part level and the appearance ratio of the pixels distributed to the brightest part level is a fourth threshold or more,
  In addition, when the ratio of the number of pixels belonging to the predetermined region at the edge of the image in the number of pixels distributed to the brightest part level by the second appearance ratio calculation means is equal to or greater than a fifth threshold value. Is considered a night scene,
The image processing apparatus according to claim 1.

When it is determined that the scene is a backlight scene by the scene determination unit , the main subject is obtained from the brightness distribution of the image data obtained by removing at least one level image from the brightest level among the plurality of brightness levels. 4. The image processing apparatus according to claim 2 , wherein the subject exposure determination unit is configured to determine whether the brightness of the subject is appropriate.

If it is determined that the scene is a night-time shooting scene by the scene determination unit, the brightness distribution of the image data obtained by removing at least one level image from the darkest level among the plurality of brightness levels 4. The image processing apparatus according to claim 2 , wherein the subject exposure determination unit is configured to determine whether or not the brightness of the subject is appropriate.

Claim 4, characterized in that the corrector as if the brightness of the main object is determined to be inappropriate by the object exposure determination means, corrects the image data of brightness vicinity of the main object Or the image processing apparatus of 5 .

In an image processing apparatus that corrects image data to image data in an optimal exposure state,
  Scene discriminating means for discriminating whether the image data is backlit scene data, night shooting scene data or other data;
  When it is determined by the scene determination means that it is neither a backlight scene nor a night shooting scene, other data,
  A frequency distribution calculating means for calculating a frequency distribution for the brightness of the image data decomposed into pixel units;
  A degree-of-bias calculation means for obtaining a degree of deviation of the frequency distribution,
  An image processing apparatus comprising: a correction unit configured to change a degree of correcting image data in a direction in which the frequency distribution with respect to brightness of the image data is further flattened based on the degree of bias of the frequency distribution.

In the image processing method for correcting image data to image data in an optimal exposure state, it is determined whether the image data is data of a backlight scene, data of a night scene, or other data,
If it is determined that it is backlit scene data or night shooting scene data, the background data is removed from the image data to determine the exposure state,
An image processing method comprising performing different image corrections based on a determination result.

A program causing a computer system to execute the image processing method according to claim 8.

A computer-readable recording medium on which the program according to claim 9 is recorded.