Image Processing Apparatus and Image Processing Method That Ensure Improved Visibility of Character After Conversion into Monochrome Image Data, and Recording Medium Therefor

An image processing method comprising:

• acquiring image data representing an image including a character;
• performing a character recognition process on the image data to extract a character region, the character region being a region where the character is represented;
• and
• converting the image data into monochrome image data when the image data is color image data including a color image, the monochrome image data including a monochrome image representing the color image with a single color;
• wherein
• when a tone difference between the extracted character region and an adjacent region is smaller than a predetermined threshold, the converting includes changing a tone of a boundary region between the character region and the adjacent region, the adjacent region being a region adjacent to the character region.

A non-transitory computer-readable recording medium storing an image processing program to control an image processing apparatus, the image processing program causing the image processing apparatus to function as:

• an image-data acquiring unit that acquires image data representing an image including a character;
• a character recognition processing unit that performs a character recognition process on the image data to extract a character region, the character region being a region where the character is represented;
• and
• a monochrome conversion unit that converts the image data into monochrome image data when the image data is color image data including a color image, the monochrome image data including a monochrome image representing the color image with a single color;
• wherein
• when a tone difference between the extracted character region and an adjacent region is smaller than a predetermined threshold, the monochrome conversion unit changes a tone of a boundary region between the character region and the adjacent region, the adjacent region being a region adjacent to the character region.