Color image was defined as a 3 dimensional array and consisted of 3 two dimensional arrays, one for
the red component, the second for the blue component and the third for green component. So it was needed
to separate red, blue and green components in order to get the gray equivalent of the color image. The gray
image then will be processed using one or more image processing techniques, after that the processed color
image will be converted back to enhanced color image. Converting color image to gray and converting the
processed gray image back to color image were the tasks that needed a lot of calculation and so a lot of
processing time. Decreasing this time to the minimum is a focal task in order to achieve an optimized processing.
HSI model of conversion was studied and a new R’G’I model also was studied and the experimental results
shows that using R’G’I model speed up the conversion and thus minimize the time at least 8 times, thus R’G’I
model can replace the HSI model in order to achieve efficient manipulation of true color image.