Image processing apparatus and method, and program

An image processing method for an image processing apparatus configured to detect a blur state of an image, the image being divided into a plurality of blocks, the image processing method comprising the steps of:

• detecting intensities of the blocks of a predetermined size;
• setting initial values of an edge reference value used for a determination as to whether or not a block is an edge point of the image, and an extraction reference value used for a determination as to whether or not a number of extracted blocks as edge points is appropriate as larger values if a dynamic range, which is a difference between a maximum value and a minimum value of the intensities of the blocks within the image, is larger;
• extracting a block as the edge point when the detected intensity of the block is equal to or larger than the edge reference value;
• determining whether or not a number of extracted blocks as edge points is appropriate by comparing the number to the extraction reference value;
• adjusting the edge reference value when the number of extracted blocks as edge points is not appropriate;
• and
• repeating the extracting step on the basis of the adjusted edge reference value until the number of extracted blocks as edge points is determined as appropriate.

A non-transitory computer-readable medium storing a program instructing a computer to execute a processing to detect a blur state of an image, the image being divided into a plurality of blocks, the program instructing the computer to execute a processing comprising the steps of:

• detecting intensities of the blocks of a predetermined size;
• setting initial values of an edge reference value used for a determination as to whether or not a block is an edge point of the image, and an extraction reference value used for a determination as to whether or not a number of extracted blocks as edge points is appropriate as larger values if a dynamic range, which is a difference between a maximum value and a minimum value of the intensities of the blocks within the image, is larger;
• extracting a block as the edge point when the detected intensity of the block is equal to or larger than the edge reference value;
• determining whether or not a number of extracted blocks as edge points is appropriate by comparing the number to the extraction reference value;
• adjusting the edge reference value when the number of extracted blocks as edge points is not appropriate;
• and
• repeating the extracting step on the basis of the adjusted edge reference value until the number of extracted blocks as edge points is determined as appropriate.

An image processing apparatus configured to detect a blur state of an image, the image being divided into a plurality of blocks, the image processing apparatus comprising:

• an edge intensity detection unit adapted to detect intensities of the plurality blocks of a predetermined size;
• a parameter adjustment unit adapted to
• adjust an edge reference value for determining whether or not a block is an edge point of the image;
• and
• adjust an extraction reference value for determining whether or not a number of extracted blocks as edge points is appropriate;
• and
• set initial values of the edge reference value and the extraction reference value as larger values if a dynamic range, which is a difference between a maximum value and a minimum value of the intensities of the blocks within the image, is larger;
• an edge point extraction unit adapted to extract a block as the edge point when the detected block intensity is equal to or larger than the edge reference value;
• and
• an extraction amount determination unit adapted to determine whether or not the number of extracted blocks as edge points is appropriate by comparing the number to the extraction reference value,
• wherein the parameter adjustment unit repeatedly performs a processing of adjusting the edge reference value such that the number of extracted blocks as edge points becomes appropriate when the number of extracted blocks as edge points is equal to or larger than the extraction reference value, and
• wherein the edge point extraction unit repeatedly performs a processing of extracting the edge points until it is determined that the number of extracted blocks as edge points is appropriate.