dkelly@npiatl.UUCP (Dwight Kelly) (02/07/90)
I am looking for a nxn blur function that would remove edges and sharp transitions from a color image. The blur would make a hires RGB image suitable for NTSC display. Would a low-pass filter transfer function work? Maybe a color Butterworth filter? Any ideas? Dwight Kelly Network Publications
forsythe@convex.com (Charles Forsythe) (02/08/90)
dkelly@npiatl.UUCP (Dwight Kelly) writes: >I am looking for a nxn blur function that would remove edges and sharp >transitions from a color image. The blur would make a hires RGB image >suitable for NTSC display. Would a low-pass filter transfer function work? Basically... >Any ideas? Here's some things that come to my mind: - Keep in mind that an NTSC is quantized vertically and analog horzontally. Although from a signal processing standpoint, this can be ignored (sort of), there is an important effect from interlace: horizontal lines one scan-line high flash annoyingly. You may want to compensate by actually reducing vertical bandwidth a little less than the available maximum. - NTSC Color information is 1/2 the badwidth of black and white. You might want to covert to YIQ coordinates and filter the IQ to more than the Y. Filtering the Y to match the IQ, which you would end up doing if you just filter RGB, will rob you of available detail. -Charles -- ======================== Send comments/flames to: forsythe@convex.com Convex does not filter outgoing posts and is not responsible for the contents therein.