JP2012165147A5

JP2012165147A5 - Image processing apparatus, control method therefor, and imaging apparatus

Info

Publication number: JP2012165147A5
Application number: JP2011023249A
Authority: JP
Filing date: 2011-02-04
Publication date: 2014-03-20
Anticipated expiration: 2031-02-04

Description

本発明は、画像処理装置およびその制御方法、ならびに撮像装置に関し、特に画像が撮像されたシーンを判別する技術に関する。 The present invention relates to an image processing apparatus, a control method thereof , and an imaging apparatus , and more particularly to a technique for determining a scene in which an image is captured.

本発明はこのような従来技術の課題に鑑みなされたものである。本発明は、シーン検出結果に応じた色補正を行う画像処理装置及びその制御方法、ならびに撮像装置において、撮像時に画角が変化した場合の色補正結果のバラツキを抑制可能とすることを目的とする。 The present invention has been made in view of the problems of the prior art. An object of the present invention is to enable an image processing apparatus that performs color correction according to a scene detection result, a control method thereof , and an imaging apparatus to suppress variations in color correction results when the angle of view changes during imaging. To do.

この目的は、画像に対し、予め定められたシーンを撮像した画像である確からしさを表すシーン信頼度を算出する信頼度算出手段と、信頼度算出手段により算出されるシーン信頼度に基づいて画像を補正する補正手段と、を有し、信頼度算出手段は、被写界輝度値に基づくシーン信頼度を算出して画像が第１のシーンである確からしさを判定し、被写界輝度値と画像に含まれる色とに基づいてシーン信頼度を算出して画像が第２のシーンである確からしさを判定し、対応する被写界輝度における、第１のシーンについてのシーン信頼度が、第２のシーンについてのシーン信頼度の算出に用いられる被写界輝度値が高いほど高くなる信頼度を、下回らないように設定されていることを特徴とする画像処理装置によって達成される。 This object is the image, based on the scene reliability and reliability calculation means for calculating a scene reliability indicating the likelihood is an image obtained by imaging the predetermined scene, which is calculated by the reliability calculation unit image anda correction means for correcting the reliability calculation means, based on the field brightness value rather calculates a scene reliability determining an image likelihood is a first scene, the object field The scene reliability is calculated based on the luminance value and the color included in the image to determine the probability that the image is the second scene, and the scene reliability for the first scene at the corresponding scene luminance. Is achieved by an image processing device characterized in that the reliability is set so as not to fall below the higher field luminance value used for calculating the scene reliability for the second scene. .

このような構成により、本発明によれば、シーン検出結果に応じた色補正を行う画像処理装置及びその制御方法、ならびに撮像装置において、撮像時に画角が変化した場合の色補正結果のバラツキを抑制することができる。 With such a configuration, according to the present invention, in the image processing apparatus that performs color correction according to the scene detection result, the control method thereof , and the imaging apparatus , variation in the color correction result when the angle of view changes during imaging is obtained. Can be suppressed.

Claims

A reliability calculation means for calculating a scene reliability representing the probability of being an image obtained by capturing a predetermined scene with respect to the image ;
Anda correction means for correcting the image based on the scene reliability calculated by the reliability calculation unit,
The reliability calculation means, color image by calculating the based rather scene reliability in field brightness value determines the likelihood is the first scene, contained in the image and the object scene brightness value Based on the above, the scene reliability is calculated to determine the probability that the image is the second scene ,
In the corresponding scene luminance, the scene reliability for the first scene does not fall below the reliability that increases as the field luminance value used for calculating the scene reliability for the second scene increases. An image processing apparatus that is set as described above .

The correction means includes
Correction amount calculating means for calculating a correction amount table for applying a predetermined correction to pixel values included in a predetermined correction range for a plurality of types of scenes;
By combining the correction amount table calculated for each of the plurality of types of scenes by applying the scene reliability of the corresponding scene, the corrected pixel value is associated with each of the input pixel values. The image processing apparatus according to claim 1, further comprising a table calculation unit that calculates a correction table.

The reliability calculation means calculates a representative color for each region obtained by dividing the image into a predetermined plurality, and the number of regions in which the representative color is included in a color range predetermined for the second scene Calculating the product of the reliability that increases as the ratio to the predetermined plurality of values increases and the reliability that increases as the field luminance value increases as the scene reliability for the second scene, The image processing apparatus according to claim 1.

The predetermined color range is determined as an area in a predetermined color space, a correction amount reduction area is further determined around the predetermined color range, and the correction amount calculation means 3. The correction amount for the color included in the amount reduction region is reduced from the correction amount for the color included in the predetermined color range as the distance from the predetermined color range increases. Alternatively, the image processing apparatus according to claim 3.

The correction amount calculation means determines that the color pixels included in a predetermined color range for the second scene include coordinates in a predetermined color space of the color before correction, and the second scene. The correction amount is calculated so as to obtain a color that exists on a straight line connecting coordinates in the predetermined color space of the corrected color when the scene reliability is maximum. 5. The image processing apparatus according to any one of 4 above.

6. The system according to claim 1, wherein the first scene is an outdoor scene, and the second scene is at least one of a blue sky scene, a natural green scene, a foliage scene, and a sunset scene. The image processing apparatus according to claim 1.

The image processing apparatus according to claim 6, wherein the reliability calculation unit calculates a scene reliability of an outdoor scene according to the field luminance value.

The reliability calculation means includes
A first reliability calculated according to a ratio of a blue sky area having a color included in a blue sky determination area set in advance in a color space, among blue sky detection areas predetermined according to the orientation of the image;
A second reliability calculated according to the field luminance value, with characteristics different from the scene reliability of the outdoor scene;
The image processing apparatus according to claim 6, wherein the scene reliability of the blue sky scene is calculated based on the above.

The reliability calculation means includes
A first reliability calculated according to a ratio of a natural green region having a color included in a natural green determination region set in advance in a color space of the image;
A second reliability calculated according to the field luminance value, with characteristics different from the scene reliability of the outdoor scene;
The image processing apparatus according to claim 6, wherein a scene reliability of a natural green scene is calculated based on the image.

The reliability calculation means includes
  A first reliability calculated according to a ratio of an evening scene area having a color included in an evening scene determination area set in advance in a color space of the image;
  A second reliability calculated according to a ratio of a non-evening scene area having a color included in a non-evening scene determination area set in advance in a color space of the image;
  A third reliability calculated according to the field luminance value, with characteristics different from the scene reliability of the outdoor scene;
The image processing apparatus according to claim 6, wherein the scene reliability of a natural green scene is calculated based on the image.

The reliability calculation means includes
A first reliability calculated according to a ratio of an autumnal area having a color included in the autumnal color determination area set in advance in the color space of the image;
A second reliability calculated according to the field luminance value, with characteristics different from the scene reliability of the outdoor scene;
The image processing apparatus according to claim 6, wherein the scene reliability of the autumnal scene is calculated based on the image quality.

Imaging means for acquiring the image by photographing;
An image processing apparatus according to any one of claims 1 to 11,
An imaging device comprising:

The image, the scene reliability indicating the likelihood is an image obtained by imaging the predetermined scene, and the reliability calculation process reliability calculation means for output calculation in the image processing apparatus,
Correction means before the SL image processing apparatus, and a correction step of correcting the image based on the scene reliability calculated by the reliability calculation unit,
Wherein said reliability calculation unit in reliability calculation step calculates the based comb over emissions confidence in field brightness value image to determine the likelihood that a first scene, the depth of field intensity Calculating the scene reliability based on the value and the color contained in the image to determine the likelihood that the image is a second scene ;
In the corresponding scene luminance, the scene reliability for the first scene does not fall below the reliability that increases as the field luminance value used for calculating the scene reliability for the second scene increases. An image processing apparatus control method characterized by being set as described above.

The program for functioning a computer as each means of the image processing apparatus of any one of Claim 1 thru | or 11 .