Automatic Color Form Dropout to Achieve Faster Document Processing
Shital A. Dhanfule, Prashant N. Pusdekar, Vinaya Vijay Gohokar · 2013
Color Dropout converts documents such as color forms to black and white images by deleting the specific color which is intended for the background or the structure of the form. After successful dropout, only the relevant information by means of Black/Blue ink or Pencil is retained. The color dropout filter parameters include the color values of the non-dropout colors, color space conversion, distance calculation, dropout threshold detection. Color dropout is accomplished by converting pixels that have color within the tolerance sphere of the non-dropout colors to black and all others to white. This is done using VHDL coding. Processing may be performed in RGB or a Luminance- Chrominance space, such as YCbCr. The color space transformation from RGB to YCbCr involves a matrix multiplication and the dropout filter implementation is similar in both cases. Result for color dropout processing in YCbCr space is presented.