KHALID%PO8600@dupont.com (09/28/89)
Has anyone worked out a method of converting RGBs to HAM. I have three B/W images (8 bits/pixel), and I would like to covert them to a HAM image. If somebody could show me the way I would not writing the C-code and making it public... Soofi
huver@amgraf.UUCP (Huver) (10/05/89)
In article <495@nigel.udel.EDU>, webb@udel.edu (David Webb) forwarded comment from Fred Mitchell (mitchell@cbmvax.uucp) on converting RGB bitmap to HAM: [...bitplane reduction, 16-color palette picking stuff deleted] But the original question was: >> >> Has anyone worked out a method of converting RGBs to HAM. I have >> three B/W images (8 bits/pixel), and I would like to covert them >> to a HAM image. If somebody could show me the way I would not writing >> the C-code and making it public... So, is Fred Mitchell at Commodore able to display B/W in HAM mode? Which Amiga model was used so that, for example, the previous pixel is 0xFFF and by HAM we can get 0x999 for the current pixel? Maybe Dave Haynie knows? It IS the rumored Amiga 3000, isn't it? :^) For original poster's benefit: HAM is for color, not B/W, display. Its only purpose in life is to let you show 4096 colors, not 4096 gray levels, from a 16-entry color palette. -huver ...!uunet!amgraf!huver
swarren@eugene.uucp (Steve Warren) (10/06/89)
In article <333@amgraf.UUCP> huver@amgraf.UUCP (Huver) writes: >In article <495@nigel.udel.EDU>, webb@udel.edu (David Webb) forwarded comment >from Fred Mitchell (mitchell@cbmvax.uucp) on converting RGB bitmap to HAM: [...bitplane reduction, 16-color palette picking stuff deleted] >But the original question was: >>> Has anyone worked out a method of converting RGBs to HAM. I have >>> three B/W images (8 bits/pixel), and I would like to covert them >>> to a HAM image. If somebody could show me the way I would not writing >>> the C-code and making it public... ... >For original poster's benefit: HAM is for color, not B/W, display. Its only >purpose in life is to let you show 4096 colors, not 4096 gray levels, from a >16-entry color palette. Well, I think he meant that he has three grey-scales of the image, one each for the red, green, and blue planes, and he wants to combine them into a single ham image. I never used it myself, but it seems like the digiview digitizer came with some software that does that (it uses a filter to digitize the image in three passes). Hope this helps. Regards, --Steve ------------------------------------------------------------------------- {uunet,sun}!convex!swarren; swarren@convex.COM
850031m@aucs.uucp (GORDON R. MAC GREGOR) (10/08/89)
In article <333@amgraf.UUCP> huver@amgraf.UUCP (Huver) writes: > >In article <495@nigel.udel.EDU>, webb@udel.edu (David Webb) forwarded comment >from Fred Mitchell (mitchell@cbmvax.uucp) on converting RGB bitmap to HAM: > >But the original question was: >>> >>> Has anyone worked out a method of converting RGBs to HAM. I have >>> three B/W images (8 bits/pixel), and I would like to covert them >>> to a HAM image. If somebody could show me the way I would not writing >>> the C-code and making it public... > [...] >For original poster's benefit: HAM is for color, not B/W, display. Its only >purpose in life is to let you show 4096 colors, not 4096 gray levels, from a >16-entry color palette. > >-huver ...!uunet!amgraf!huver I believe the origional question was stated quite clearly. He has 3 B&W images corresponding to the Red, Green and Blue color intensities of the in-color picture. Were Digi-View the only ones to come up with a good RGB to HAM algorithm? Methinks this be the question. -ross
jmdavis@cbnewsd.ATT.COM (j.michael.davis) (10/09/89)
In article <1976@convex.UUCP> swarren@eugene.UUCP (Steve Warren) writes: >>>> Has anyone worked out a method of converting RGBs to HAM. I have >>>> three B/W images (8 bits/pixel), and I would like to covert them >Well, I think he meant that he has three grey-scales of the image, one each Yea. >I never used it myself, but it seems like the digiview digitizer According to the docs on DigiPaint 3, Transfer 24 (which was included with DigiP3) does this, but apparently in Newtek's format. I had 3 files R,G,B that I made with Sculpt that were 8 bits per pixel and tried to get T24 to HAM them. Apparently T24 expects ONE file with the R,G,B sections in them. PIXMATE also does this, quite well, with 3 files!!! But it only does it in 4 bits per pixel. (At least that was all I tried.) -- ---------------------------------------------------------------------------- I am just about fed up | Mike Davis and I will only take it | ..!att!ihlpm!jmdavis a few more times. |
kenb@clmqt.marquette.Mi.US (Ken Baynard) (10/10/89)
swarren@eugene.uucp (Steve Warren) writes: >In article <333@amgraf.UUCP> huver@amgraf.UUCP (Huver) writes: >>In article <495@nigel.udel.EDU>, webb@udel.edu (David Webb) forwarded comment >>from Fred Mitchell (mitchell@cbmvax.uucp) on converting RGB bitmap to HAM: > [...bitplane reduction, 16-color palette picking stuff deleted] >>But the original question was: >>>> Has anyone worked out a method of converting RGBs to HAM. I have >>>> three B/W images (8 bits/pixel), and I would like to covert them >>>> to a HAM image. If somebody could show me the way I would not writing >>>> the C-code and making it public... > ... >I never used it myself, but it seems like the digiview digitizer >came with some software that does that (it uses a filter to digitize >the image in three passes). > {uunet,sun}!convex!swarren; swarren@convex.COM Well you're close. Digi-View won't actually do the coloring for you. It can be used to modify the picture however in terms of intensity, brightness, and contrast. To take a B/W or say 16 gray scale picture, its best to use either Digi Paint or Photon Paint. Using the subtract option with either of these, you can color in the various shades of gray accoringly and at the end have a HAM picture. I've used the technique quite a bit with fairly impressive results. The key is to have a good B/W picture to start with. Hope this helps a bit.
swarren@eugene.uucp (Steve Warren) (10/10/89)
In article <55@clmqt.marquette.Mi.US> kenb@clmqt.marquette.Mi.US (Ken Baynard) writes: >swarren@eugene.uucp (Steve Warren) writes: >>>>> Has anyone worked out a method of converting RGBs to HAM. I have >>>>> three B/W images (8 bits/pixel), and I would like to covert them >>>>> to a HAM image. If somebody could show me the way I would not writing >>>>> the C-code and making it public... >> ... > >>I never used it myself, but it seems like the digiview digitizer >>came with some software that does that (it uses a filter to digitize >>the image in three passes). > >> {uunet,sun}!convex!swarren; swarren@convex.COM > Well you're close. Digi-View won't actually do the coloring for >you. It can be used to modify the picture however in terms of >intensity, brightness, and contrast. To take a B/W or say 16 gray >scale picture, its best to use either Digi Paint or Photon Paint. >Using the subtract option with either of these, you can color in the >various shades of gray accoringly and at the end have a HAM picture. >I've used the technique quite a bit with fairly impressive results. >The key is to have a good B/W picture to start with. Hope this helps >a bit. OK, allow me to ask a few questions, because mainly I was correcting a misunderstanding that another fellow had about the problem. Are you saying that using Digi Paint or Photon Paint he will be able to load in a 16 grey-scale picture and change it to a 16-level red only picture, without doing any manual "painting" on the picture itself? Of course then he would have to do the same with the blue and the green pictures. Then the three "colorized" pictures must be added together in such a way that R+G+B=white, and all the variations in between. If Digi Paint or Photon Paint can do all this, then one of these programs will do the job for him. But he still has to figure out how to get from 8-bits to 4-bits per color plane. He will probably need a better algorithm than "divide-by-16" to get good results. Any suggestions from image people on the best way to drop 4 bits? --Steve ------------------------------------------------------------------------- {uunet,sun}!convex!swarren; swarren@convex.COM
mitchell@cbmvax.UUCP (Fred Mitchell - QA) (10/24/89)
In article <333@amgraf.UUCP> huver@amgraf.UUCP (Huver) writes: > >In article <495@nigel.udel.EDU>, webb@udel.edu (David Webb) forwarded comment >from Fred Mitchell (mitchell@cbmvax.uucp) on converting RGB bitmap to HAM: > > [...bitplane reduction, 16-color palette picking stuff deleted] > >But the original question was: >>> >>> Has anyone worked out a method of converting RGBs to HAM. I have >>> three B/W images (8 bits/pixel), and I would like to covert them >>> to a HAM image. If somebody could show me the way I would not writing >>> the C-code and making it public... > >So, is Fred Mitchell at Commodore able to display B/W in HAM mode? Which >Amiga model was used so that, for example, the previous pixel is 0xFFF and by >HAM we can get 0x999 for the current pixel? Maybe Dave Haynie knows? It IS >the rumored Amiga 3000, isn't it? :^) I was speaking of the more general *color* case. Obviously, in the n-bit b&w case, to convert it to m bits, where m < n, you drop the lower n - m bits. You can also employ some type of dithering scheme if m is very small ( <= 3 bits ), but that's another story.