Image processor for detecting specified pattern

A method of image processing to detect a circular pattern in an image comprising the steps of:

• binarizing input image data to provide bi-level image data;
• counting pixels having a predetermined value in a block of a polygon having n vertices in the bi-level image data, wherein n denotes a natural number equal to or larger than eight;
• and
• deciding, based on a number of the pixels having the predetermined value, whether the circular pattern is detected in the image or not.

A recording medium storing a program to be executed by a computer, the program comprising the steps of:

• binarizing input image data to provide bi-level image data;
• counting pixels having a predetermined value in a block of a polygon having n vertices in the bi-level image data, wherein n denotes a natural number equal to or larger than eight;
• and
• deciding, based on a number of the pixels having the predetermined value, whether the circular pattern is detected in the image or not.

An image processor for detecting a specified pattern in an image comprising:

• a controller which sets a detection window in input image data to detect the specified pattern and moves the detection window successively by a predetermined number of pixels;
• and
• a detector which scans the image data from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• wherein said controller decides a width of scan until which said detector detects a rim of the specified pattern, in a direction in correspondence to the moving direction of the detection window, and changes a moving distance of the detection window based on the decided width of scan.

An image processor for detecting a specified pattern in an image comprising:

• a controller which sets a quadrilateral detection window to detect the specified pattern and moves the detection window successively by a predetermined number of pixels;
• and
• a detector which scans the image from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• wherein said detector detects the rim of the specified pattern first in a moving direction of the detection window and next in a direction vertical to the moving direction.

A method of image processing to detect a specified pattern in an image comprising the steps of:

• setting a detection window to detect the specified pattern and moving the detection window successively by a predetermined number of pixels;
• scanning the image from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• deciding a width of scan until the rim of the specified pattern is detected, in a direction in correspondence to the moving direction of the detection window;
• and
• changing a moving distance of the detection window based on the decided width of scan.

A recording medium storing a program to be executed by a computer, the program comprising the steps of:

• setting a detection window to detect the specified pattern and moving the detection window successively by a predetermined number of pixels;
• scanning the image from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• deciding a width of scan until the rim of the specified pattern is detected, in a direction in correspondence to the moving direction of the detection window;
• and
• changing a moving distance of the detection window based on the decided width of scan.

A method of image processing to detect a specified pattern in an image comprising the steps of:

• setting a quadrilateral detection window to detect the specified pattern and moving the detection window successively by a predetermined number of pixels;
• and
• scanning the image from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• wherein the rim of the specified pattern is detected first in a moving direction of the detection window and next in a direction vertical to the moving direction.

A recording medium storing a program to be executed by a computer, the program comprising the steps of:

• setting a quadrilateral detection window to detect the specified pattern and moving the detection window successively by a predetermined number of pixels;
• and
• scanning the image from each side of the detection window towards the center thereof to detect a rim of the specified pattern;
• wherein the rim of the specified pattern is detected first in a moving direction of the detection window and next in a direction vertical to the moving direction.