Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!swrinde!ucsd!ucbvax!hplabs!hp-sdd!tony From: tony@hp-sdd.hp.com (Tony Parkhurst) Newsgroups: comp.sys.amiga Subject: Re: digiview -> IFF Message-ID: <2518@hp-sdd.hp.com> Date: 5 Sep 89 17:22:47 GMT References: <2514@hp-sdd.hp.com> <557@tardis.Tymnet.COM> Reply-To: tony@hp-sdd.UUCP (Tony Parkhurst) Organization: Hewlett Packard, San Diego Lines: 67 In article <557@tardis.Tymnet.COM> jms@tardis.Tymnet.COM (Joe Smith) writes: >In article <2514@hp-sdd.hp.com> tony@hp-sdd.UUCP (Tony Parkhurst) writes: >>In article MSW@mplvax.sri.com (Mark S. Williams) writes: >>>I got the Neptune pictures from Stanford and uncompressed them on my >>>amiga. Now what do I do - I don't have DigiView. Is there some way to >>>convert a DigiView picture to IFF? >>uuuuuuuhh... Well, actually, DigiView pictures ARE in IFF format, they just >>aren't immediately displayable because they use 21 planes of direct color, >>insted of 1 to 6 planes indexed. I believe that the Neptune pictures are >>in GIF format (at least the ones I got were), so you need a GIF to IFF >>converter, and as someone pointed out, these pics are monocrome, and 256 >>levels of grey, so they probably won't display well on the amiga. >Sorry, you've got it all wrong. Normally, I don't mind someone correcting me on a few points, but I get a little annoyed with the "you're all wrong" attitude, especially when it ain't so. >When you tell DigiView to "Save RBG", it saves the raw data. Width times >height bytes of red data, that many bytes of blue data, and the same for >green data. There is no "FORM", no byte count, no ILBM, no color palette, >nothing but raw data. That is NOT IFF format. DigiView recognizes raw >data only if the length of the input file exactly matches the current >screen resolution (for monochrome) or exactly 3 times the number of >pixels on the screen (for RGB). So, "You've got it all wrong." Have you looked at the output from DigiView, it indeed DOES have a FORM, ILBM, but no color map. It follows the IFF standard perfectly. It just uses 21 planes of data, 7 each of R, G, and B. (If you would like, I can post a program I wrote that will read this file,etc) While it might be so that you can read "raw" (not IFF) RGB into DigiView, the "Save RGB" _does_ output an IFF file less a color palette. If you look in the BMHD chunk, it specifies number of planes as 21 instead of the usual 1 thru 6. (At least with DigiView version 3.0). >The pictures from Stanford are raw monochrome data, not GIF. After using >the "uncompress" program on *.Z, if you try "1>TYPE TRITON HEX" you will >see that the bytes range from 00 to 0F only. That is, these pictures >use only 16 out of 256 potential levels of gray. They do display well >on the Amiga. The pictures I got from a different machine were in GIF format, and used all 256 levels a grey, with a resolution of 640 by 480. They look like they were created by a framegrabber, from a video source, and it looks like it was shot directly from the screen of some NASA type computer (complete with info showing data correction). However, the picture that someone posted here (from the Stanford machine), and said to be processed by DigiView, has a resolution of 320 by 216, has a 16 color palette, and is in HAM mode (6 planes). It also is in color. I am curious as to WHY it has color. (It is pretty tho.) I did not see the broadcast "live" of these pictures, but I thought that they were sent in monocrome from Voyager, and color processed later. So, if this is the case, who added the color? NASA, or some Amiga junkie :-? -- Tony -- Tony Parkhurst ( tony@hp-sdd.HP.COM ) "Is this Hell? Or is this Texas?" "Both" -- Heinlein, _J_O_B: _A _C_o_m_e_d_y _o_f _J_u_s_t_i_c_e