Image processing apparatus for detecting a noise line based on noise pixels in the shadow region

A control method of an image processing apparatus, the method comprising:

• acquiring an input image of a document and a periphery of the document;
• extracting first edge pixels from the input image;
• detecting a document region based on the first edge pixels;
• detecting a shadow region from within a predetermined range outside of the document region;
• extracting noise pixels in the shadow region;
• detecting the noise pixels, a number of which connected with one another is equal to or more than a predetermined number, as a noise line;
• and
• correcting the document region of the input image based on a detection result of the noise line.

A computer-readable, non-transitory medium storing a computer program, wherein the computer program causes an image processing apparatus to execute a process, the process comprising:

• acquiring an input image of a document and a periphery of the document;
• extracting first edge pixels from the input image;
• detecting a document region based on the first edge pixels;
• detecting a shadow region from within a predetermined range outside of the document region;
• extracting noise pixels in the shadow region;
• detecting the noise pixels, a number of which connected with one another is equal to or more than a predetermined number, as a noise line;
• and
• correcting the document region of the input image based on a detection result of the noise line.