Apparatus, method and program for image processing
For enabling a change in lighting pattern in an image, adjustment of a shadow pattern is aimed at in an image. For this purpose, a parameter acquisition unit obtains weighting parameters representing the shadow pattern in a face region in the image by fitting to the face region detected by a face detection unit a mathematical model generated by a method of AAM using a plurality of sample images representing human faces in different lighting conditions. A shadow pattern adjustment unit adjusts the shadow pattern in the face region based on the weighting parameters having been obtained.
1 . An image processing apparatus comprising:
parameter acquisition means for obtaining a weighting parameter for a statistical characteristic quantity representing a pattern of shadows in a predetermined structure in an input image by fitting a model representing the structure to the structure in the input image, the model having been obtained by carrying out predetermined statistical processing on a plurality of images representing the predetermined structure in different lighting conditions, and the model representing the structure by one or more statistical characteristic quantities including the statistical characteristic quantity representing the pattern of shadows in the structure and by weighting parameter or parameters for weighting the statistical characteristic quantity or quantities according to an individual characteristic of the structure; and
shadow pattern adjustment means for adjusting the pattern of shadows in the structure in the input image according to the weighting parameter after changing a value of the weighting parameter.
2 . The image processing apparatus according to claim 1 , wherein the predetermined structure is a human face.
3 . The image processing apparatus according to claim 1 further comprising detection means for detecting the structure in the input image, wherein
the parameter acquisition means obtains the weighting parameter by fitting the model to the structure having been detected.
4 . The image processing apparatus according to claim 1 further comprising selection means for obtaining a property of the structure in the input image and for selecting the model corresponding to the obtained property from a plurality of the models representing the structure for respective properties of the predetermined structure, wherein
the parameter acquisition means obtains the weighting parameter by fitting the selected model to the structure in the input image.
5 . An image processing method comprising the steps of:
obtaining a weighting parameter for a statistical characteristic quantity representing a pattern of shadows in a predetermined structure in an input image by fitting a model representing the structure to the structure in the input image, the model having been obtained by carrying out predetermined statistical processing on a plurality of images representing the predetermined structure in different lighting conditions, and the model representing the structure by one or more statistical characteristic quantities including the statistical characteristic quantity representing the pattern of shadows in the structure and by weighting parameter or parameters for weighting the statistical characteristic quantity or quantities according to an individual characteristic of the structure; and
changing a value of the weighting parameter and adjusting the pattern of shadows in the structure in the input image according to the weighting parameter having been changed.
6 . The image processing method according to claim 5 , wherein the predetermined structure is a human face.
7 . The image processing method according to claim 5 further comprising the step of detecting the structure in the input image, wherein
the step of obtaining the weighting parameter is the step of obtaining the weighting parameter by fitting the model to the structure having been detected.
8 . The image processing method according to claim 5 further comprising the steps of obtaining a property of the structure in the input image and selecting the model corresponding to the obtained property from a plurality of the models representing the structure for respective properties of the predetermined structure, wherein
the step of obtaining the weighting parameter is the step of obtaining the weighting parameter by fitting the selected model to the structure in the input image.
9 . An image processing program for causing a computer to function as:
parameter acquisition means for obtaining a weighting parameter for a statistical characteristic quantity representing a pattern of shadows in a predetermined structure in an input image by fitting a model representing the structure to the structure in the input image, the model having been obtained by carrying out predetermined statistical processing on a plurality of images representing the predetermined structure in different lighting conditions, and the model representing the structure by one or more statistical characteristic quantities including the statistical characteristic quantity representing the pattern of shadows in the structure and by weighting parameter or parameters for weighting the statistical characteristic quantity or quantities according to an individual characteristic of the structure; and
shadow pattern adjustment means for adjusting the pattern of shadows in the structure in the input image according to the weighting parameter after changing a value of the weighting parameter.
10 . The image processing program according to claim 9 , wherein the predetermined structure is a human face.
11 . The image processing program according to claim 9 for causing the computer to further function as detection means for detecting the structure in the input image; and
the parameter acquisition means for obtaining the weighting parameter by fitting the model to the structure having been detected.
12 . The image processing program according to claim 9 for causing the computer to further function as selection means for obtaining a property of the structure in the input image and for selecting the model corresponding to the obtained property from a plurality of the models representing the structure for respective properties of the predetermined structure; and
the parameter acquisition means for obtaining the weighting parameter by fitting the selected model to the structure in the input image.