Computer Graphics :: Forum

In DIRECT CODING we use 3bytes per pixel(as an accepted standard) with one byte for each primary color. Hence, each primary can have 256 different intesntiy level so we have a total of 256*256*256 poosible intensity level.

this is the true color representation. but the problem is a 1000*1000 true color image would take up 3 million bytes and also if each pixel in this image had a different color, there would only be 1 million colors so this representaion of 16.7 million diff colors is somewhat not practical.

 Hence we have LOOKUP TABLE . in this the pixel values do not code colors directly instead the have the addresses or indices into a table of color values.

there is a table having 256 entries each of 24 bits color value(8 bits per primary). Pixel values are now 1 byte telling number from 0 to 255 in the table where a color value is stored.

so a 1000*1000 image now requires 1 million+768 bytes( for the color values in lookup table). hence it allows 256 simultaneous colors that are chosen from 16.7 million possible colors.