Treat the file as Image in raw format (rows are listed one after another in row based order).

Define image matrix as

unsigned char image_input[height][width], image_output[height][width];

where height is 500 pixels and width is 750 pixels for the sample of gray level image (non-interlace).

Input and output data using fread and fwrite instructions same as above.

After input, make image margins of 15 pixel belts half-transparent, and then output the image. Transparency can use the composition of "30% front glass intensity + 70% back image intensity" as output in the margin areas.

Check the result using Adobe Photoshop by opening raw image format with channel number 1, correct width and height, and non-interlaced format.