Abstract
This paper proposes a thresholding technique to segment an objective area that has a large difference of gray level and a long boundary between the background area in a gray-scaled image. The average of the gray levels of the pixels with the edge strength that has the maximum frequency in the image is set as the threshold for binarization. The experimental results show that most resultant images by the proposed method were similar to the results by the conventional method that is based on the discriminatory analysis. On the other hand, characters were segmented clearly by the proposed method in the experimental images with shading. The proposed method is expected to apply to various gray-scaled images because it has the simple process and it can determine a threshold automatically without any external parameters to control the process.
