johnm@spudge.UUCP (John Munsch) (11/01/89)
What is the official IFF format for 24bit/pixel pictures? Is it just a FORM ILBM with 24 interleaved bitplanes, no CMAP, and some decree that (for example) the first 8 planes represent the red component the next 8 green, etc. Actually, I kind of hope not, because bitplanes work great for the Amiga's display but they are an awful way to store that data for other work. If not then could someone who knows please clarify? I would like to write some tools to perform overlays, display 24bit/pixel pics, etc. but I want to know that I'm going to fit to whatever the standard is. NOTE: Even if the standard is 24 interleaved bitplanes I'll conform because I consider the standard more important than my own convenience. John Munsch
ralph@atrp.mit.edu (Ralph L. Vinciguerra) (11/03/89)
I'm interested in extensions to IFF also. With the advent of TI 34010 based boards for the A2000, and the utility of IFF in other places (like a VAX at work), I'd also like to here of any extensions to IFF to allow 24-bit truecolor (or even more, like Landsat images) storage. I'm thinking of defining an alternate to ILBM chunks which allow non-bitplane interleaved image storage (like perhaps line interleaved instead).
limonce@pilot.njin.net (Tom Limoncelli) (11/04/89)
In article <932@mit-amt.MEDIA.MIT.EDU> ralph@atrp.mit.edu (Ralph L. Vinciguerra) writes: [deleted] > I'd > also like to here of any extensions to IFF to allow 24-bit truecolor > (or even more, like Landsat images) storage. I was told that at the last DevCon, C-A officially adopted ASDG's 24-bitplane IFF format (they worked together to iron out the specifics). > I'm thinking of defining an alternate to ILBM chunks which > allow non-bitplane interleaved image storage (like perhaps line interleaved > instead). That's called "chunky" bitmaps, and it's usually done on a per-pixel basis. It is *much* easier for a program to work with if one is doing internal calculations. At DevCon, C-A officially adopted a chunky bitmap IFF spec (which was co-developed by ASDG & C-A) (DISCLAIMER: I'm not associated with ASDG or C-A and I wasn't at DevCon, but this is what I recall from some net (and non-net) summaries of the last DevCon. I'm sure I'll be flameboyantly corrected for any discrepancies :-)) -- Drew University -- Tom Limoncelli C M Box 1060 -- limonce@pilot.njin.net limonce@pilot.rutgers.edu P O Box 802 -- tlimonce@drunivac.Bitnet <<<-has a "T" in it. Madison, NJ 07940 -- 201-408-5389 ...!rutgers!njin!limonce Arriving soon to a Usenet map near you: ...!rutgers!njin!drew!tlimonce
aaron@madnix.UUCP (Aaron Avery) (11/04/89)
In article <5342@spudge.UUCP> johnm@spudge.UUCP (John Munsch) writes: >What is the official IFF format for 24bit/pixel pictures? Is it just a >FORM ILBM with 24 interleaved bitplanes, no CMAP, and some decree that >(for example) the first 8 planes represent the red component the next 8 >green, etc. Actually, I kind of hope not, because bitplanes work great for >the Amiga's display but they are an awful way to store that data for other >work. Yes. That's basically it. Yes, it's a pain to do image processing unless the data is in chunky pixel format, but also, many current graphics processors allow you to specify bitplane or chunky format for the display. Also, 24-bit files stored in bitplane format compress quite well, due to the equally-significant bits being stored together. As to the standard... Store a BMHD indicating 24 bitplanes. No CMAP, but don't bomb if you find one; just ignore it. Within the BODY, the bitplane ordering is as follows: bit 0 of red ... bit 7 of red bit 0 of green ... bit 7 of green bit 0 of blue ... bit 7 of blue Thus, any reader which can currently deal with an 8-bit ILBM, should have no trouble, as the bitplanes are in the same order as an 8-bit ILBM would be, for each of red, green and blue. This can also be extended to fewer bitplanes, such as 18, as long as it's divisible by 3. - Aaron -- Aaron Avery, ASDG Inc. "A mime is a terrible thing to waste." -- Robin Williams ARPA: madnix!aaron@cs.wisc.edu {uunet|ncoast}!marque! UUCP: {harvard|rutgers|ucbvax}!uwvax!astroatc!nicmad!madnix!aaron
eric@topaz.rutgers.edu (Eric Lavitsky) (11/05/89)
In article <Nov.3.11.11.45.1989.8156@pilot.njin.net> limonce@pilot.njin.net (Tom Limoncelli) writes: > In article <932@mit-amt.MEDIA.MIT.EDU> ralph@atrp.mit.edu (Ralph L. Vinciguerra) writes: > <much deleted> > > I'm thinking of defining an alternate to ILBM chunks which > > allow non-bitplane interleaved image storage (like perhaps line interleaved > > instead). > > That's called "chunky" bitmaps, and it's usually done on a per-pixel > basis. It is *much* easier for a program to work with if one is doing > internal calculations. At DevCon, C-A officially adopted a chunky > bitmap IFF spec (which was co-developed by ASDG & C-A) The 24-Bit IFF standard is *not* chunky. It is rather a natural extension of the ILBM spec to support images up to 24-bitplanes. It was developed by ASDG - the only thing that was changed in the final spec due to external input was removal of ASDG's improper usage of the CMAP chunk for color correction information. A new chunk has been added for color correction, but the exact name escapes me at the moment. The latest format can be found on BIX in amiga.dev/iff ... > (DISCLAIMER: I'm not associated with ASDG or C-A and I wasn't at > DevCon, but this is what I recall from some net (and non-net) > summaries of the last DevCon. I'm sure I'll be flameboyantly > corrected for any discrepancies :-)) I'm also not associated with ASDG, but I was at DevCon and I am an interested party since my company's products support 24-bit image processing. > Drew University -- Tom Limoncelli -- Eric Lavitsky UUCP: ...rutgers!tstream!eric Active Circuits, Inc. eric@topaz.rutgers.edu 201-223-5999 BIX: eric
limonce@pilot.njin.net (Tom Limoncelli) (11/05/89)
In article <Nov.3.11.11.45.1989.8156@pilot.njin.net> I wrote: [ discussion of 24-bit/pixel BITPLANE-interleaved IFF spec followed closely by 24-bit/pixel BIT-interleaved IFF spec. ] In article <Nov.4.14.46.13.1989.23574@topaz.rutgers.edu> eric@topaz.rutgers.edu (Eric Lavitsky) writes: > The 24-Bit IFF standard is *not* chunky. It is rather a natural > extension of the ILBM spec to support images up to 24-bitplanes. It > was developed by ASDG - the only thing that was changed in the final Absolutely. I thought I made it clear that they are two different specs, but I guess it wasn't clear enough. I thought I had (I was answering two different questions and each was set off by a different quote. From a literary standpoint, I didn't leave enough transition between the two topics and they sounded (to some) like I meant they were the same spec. > Eric Lavitsky UUCP: ...rutgers!tstream!eric -- Tom Limoncelli -- limonce@pilot.njin.net Standard Disclaimer CM 1060 -- tlimonce@drunivac.bitnet P O Box 802 -- ...!rutgers!njin!drew!tlimonce Madison, NJ 07940 -- 201-408-5389 "I do not like green eggs and spam, I do not like them, Sam I am!"
johnm@spudge.UUCP (John Munsch) (11/06/89)
Does anyone yet have programs that comply with ASDG/Commodore's standard for 24bits/pixel? I would like to maybe get ahold of something that does (or at least some sample images. I don't take anything for granted... John Munsch