Image collating apparatus for comparing/collating images before/after predetermined processing, image forming apparatus, image collating method, and image collating program product

An image forming apparatus which forms a reference image as a criterion, and an image based on the reference image, comprising an image collating unit including:

• means for setting a plurality of predetermined paths in the reference image, and accumulating pixel values in the paths with respect to the plurality of paths to obtain a projected waveform or histogram of the reference image;
• means for obtaining the formed image as a check image, setting the plurality of predetermined paths in the check image, and accumulating the pixel values in the paths with respect to the plurality of paths to obtain the projected waveform or histogram of the check image;
• means for extracting information of a characteristic value as reference characteristic value information from the projected waveform or histogram of the reference image;
• means for extracting information of the characteristic value as check characteristic value information from the projected waveform or histogram of the check image;
• and
• means for collating the reference image with the check image based on the reference characteristic value information and check characteristic value information.

An image collating method for collating a reference image as a criterion with a check image obtained by subjecting the reference image to predetermined processing, comprising:

• a step of setting a plurality of predetermined paths in the reference image, and accumulating pixel values in the paths with respect to the plurality of paths to obtain a projected waveform or histogram of the reference image;
• a step of setting the plurality of predetermined paths in the check image, and accumulating the pixel values in the paths with respect to the plurality of paths to obtain the projected waveform or histogram of the check image;
• a step of extracting information of a characteristic value as reference characteristic value information from the projected waveform or histogram of the reference image;
• a step of extracting information of the characteristic value as check characteristic value information from the projected waveform or histogram of the check image;
• and
• a step of collating the reference image with the check image based on the reference characteristic value information and check characteristic value information.

An image collating program product which collates a reference image as a criterion of processing with a check image obtained by subjecting the reference image to predetermined processing and which allows a computer to execute the processing including:

• a procedure of setting a plurality of predetermined paths in the reference image, and accumulating pixel values in the paths with respect to the plurality of paths to obtain a projected waveform or histogram of the reference image;
• a procedure of setting the plurality of predetermined paths in the check image, and accumulating the pixel values in the paths with respect to the plurality of paths to obtain the projected waveform or histogram of the check image;
• a procedure of extracting information of a characteristic value as reference characteristic value information from the projected waveform or histogram of the reference image;
• a procedure of extracting information of the characteristic value as check characteristic value information from the projected waveform or histogram of the check image;
• and
• a procedure of collating the reference image with the check image based on the reference characteristic value information and check characteristic value information.