[GRASS-user] Problems with i.rgb.his

GRASS GRASS user
1

I have an image that looks good using rgb composting:

d.rgb red=image.r green=image.g blue=image.b

Now I try to convert it to his format:

i.rgb.his red=image.r green=image.g blue=image.b hue=image.h
int=image.i sat=image.s

but

d.his h=image.h i=image.i s=image.s

doesn't look anything like the original.

What step(s) am I forgetting?

Thanks

--
David Finlayson

2

David Finlayson wrote:

I have an image that looks good using rgb composting:

d.rgb red=image.r green=image.g blue=image.b

Now I try to convert it to his format:

i.rgb.his red=image.r green=image.g blue=image.b hue=image.h
int=image.i sat=image.s

but

d.his h=image.h i=image.i s=image.s

doesn't look anything like the original.

What step(s) am I forgetting?

i.rgb.his actually converts to something which could reasonably be
termed HIS/HSV/HSB, whereas d.his is a kludge; the conversion which it
performs doesn't correspond to anything which you are likely to find
in a computer graphics text.

The hsv.rgb.sh script in 5.x is probably a lot closer to what you are
looking for.

http://freegis.org/cgi-bin/viewcvs.cgi/*checkout*/grass/src/scripts/shells/hsv.rgb.sh?rev=1.2&content-type=text/plain
http://freegis.org/cgi-bin/viewcvs.cgi/*checkout*/grass/src/scripts/shells/rgb.hsv.sh?rev=1.2&content-type=text/plain

--
Glynn Clements <glynn@gclements.plus.com>