Background pattern image combining apparatus, background pattern image combining method, and computer-readable storage medium for computer program

A background pattern image combining method for combining a background pattern image with an input image, the background pattern image including a plurality of first isolated points having a size that can be read by an image reader and a plurality of second isolated points having a size that cannot be read by the image reader, the background pattern image combining method comprising:

• detecting, in the input image, a specific area which is an area having a specific state;
• and
• combining the background pattern image with the input image by placing not the plurality of first isolated points but the plurality of second isolated points in the specific area, and, by placing the plurality of first isolated points and the plurality of second isolated points in an area other than the specific area.

A non-transitory computer-readable storage medium storing thereon a computer program used in a computer for combining a background pattern image with an input image, the background pattern image including a plurality of first isolated points having a size that can be read by an image reader and a plurality of second isolated points having a size that cannot be read by the image reader, the computer program causing the computer to perform:

• a first process for detecting, in the input image, a specific area which is an area having a specific state;
• and
• a second process for combining the background pattern image with the input image by placing not the plurality of first isolated points but the plurality of second isolated points in the specific area, and, by placing the plurality of first isolated points and the plurality of second isolated points in an area other than the specific area.