clldomps@cs.ruu.nl (Louis van Dompselaar) (04/08/91)
Hi there! I'm working with Yamaha's V9958 videochip which can generate 19268 colours in only 64k of video RAM. For those of you who are not familiar (I guess that's quite a lot :-) ), here's how it works: Colour selection is made with four pixels: 7 6 5 4 3 2 1 0 Dot 0 Y1 | KL Dot 1 Y2 | KH Dot 2 Y3 | JL Dot 3 Y4 | JH The KL,KH,JL and JH values determine a kind-of 'base' colour, from which each of the four pixels can differ with an intensity value Y. The formulas are: Y = B/2 + R/4 + G/8 J = R - Y K = G - Y Anyway, the question is: given four pixels with each individual R,G and B values, how to determine the correct J and K for these pixels and the Y values for each pixel individually??? Thanks for any help Louis van Dompselaar clldomps@praxis.cs.ruu.nl