Character area extracting device, imaging device having character area extracting function, recording medium saving character area extracting programs, and character area extracting method

An imaging device having a character area extracting device comprising:

• an image input unit configured to receive image data obtained by photographing a photographic subject;
• an image memory unit configured to store the received image data;
• a reflective and non-reflective area separation unit configured to binarize the image data with a first threshold value, separate the image data into a reflective area in which a pixel value is saturated and a non-reflective area in which the pixel value is not saturated, and binarize the image data by changing the first threshold value when it is determined that the first threshold value is evaluated not to be appropriate;
• a reflective area binarizing unit configured to binarize the reflective area of the image data with a second threshold value, separate the reflective area into a character area and a background area, and binarize the reflective area by changing the second threshold value when it is determined that the second threshold value is evaluated not to be appropriate;
• a non-reflective area binarizing unit configured to binarize the non-reflective area of the image data with a third threshold value, separate the non-reflective area into the character area and the background area, and binarize the non-reflective area by changing the third threshold value when it is determined that the third threshold value is evaluated not to be appropriate;
• a reflective and non-reflective area separation evaluation unit configured to evaluate the first, the second and the third threshold values using results of the separations with the reflective area binarizing unit and the non-reflective area binarizing unit;
• and
• a line extracting unit configured to connect the character area of the reflective area and the character area of the non-reflective area and extract positional information of the connected character area in the image data.

A non-transitory recording medium storing a character area extracting program representing a sequence of instructions, the instructions of the character area extracting program which when executed by a computer causing the computer to function as:

• an image input unit configured to receive image data obtained by photographing a photographic subject;
• an image memory unit configured to store the received image data;
• a reflective and non-reflective area separation unit configured to binarize the image data with a first threshold value, separate the image data into a reflective area in which a pixel value is saturated and a non-reflective area in which the pixel value is not saturated, and binarize the image data by changing the first threshold value when it is determined that the first threshold value is evaluated not to be appropriate;
• a reflective area binarizing unit configured to binarize the reflective area of the image data with a second threshold value, separate the reflective area into a character area and a background area, and binarize the reflective area by changing the second threshold value when it is determined that the second threshold value is evaluated not to be appropriate;
• a non-reflective area binarizing unit configured to binarize the non-reflective area of the image data with a third threshold value, separate the non-reflective area into the character area and the background area, and binarize the non-reflective area by changing the third threshold value when it is determined that the third threshold value is evaluated not to be appropriate;
• a reflective and non-reflective area separation evaluation unit configured to evaluate the first, the second and the third threshold values using results of the separations with the reflective area binarizing unit and the non-reflective area binarizing unit;
• and
• a line extracting unit configured to connect the character area of the reflective area and the character area of the non-reflective area and extract positional information of the connected character area in the image data.

A character area extracting method comprising:

• binarizing image data obtained by photographing a photographic subject with a first threshold value by separating the image data into a reflective area in which a pixel value is saturated and a non-reflective area in which the pixel value is not saturated and binarizing the image data by changing the first threshold value when it is determined that the first threshold value is evaluated not to be appropriate;
• binarizing the reflective area of the image data with a second threshold value by separating the reflective area into a character area and a background area and by binarizing the reflective area by changing the second threshold value when it is determined that the second threshold value is evaluated not to be appropriate;
• binarizing the non-reflective area of the image data with a third threshold value by separating the non-reflective area into the character area and the background area and binarizing the non-reflective area by changing the third threshold value when it is determined that the third threshold value is evaluated not to be appropriate;
• evaluating the first, the second and the third threshold values using results of the separations;
• connecting the character area of the reflective area and the character area of the non-reflective area;
• and
• extracting positional information of the connected character area in the image data.