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From: lsr@apple.UUCP (Larry Rosenstein)
Newsgroups: comp.sys.mac
Subject: Re: Color MacPaint file format
Message-ID: <6163@apple.UUCP>
Date: Sun, 6-Sep-87 16:56:48 EDT
Article-I.D.: apple.6163
Posted: Sun Sep  6 16:56:48 1987
Date-Received: Sun, 6-Sep-87 23:36:20 EDT
References: <2862@crcge1.UUCP> <3789@sdcsvax.UCSD.EDU>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Organization: Advanced Technology Group, Apple Computer
Lines: 41

In article <3789@sdcsvax.UCSD.EDU> jww@sdcsvax.UCSD.EDU (Joel West) writes:
>
>The color painting program that most people have seen is ATG Paint, from
>Apple's Advanced Technology Group (yep, apple!lsr had a major hand in it).
>It uses a radical new format: PICT.
>
>Q: PICT?  You mean like "Save as PICT" in MacDraw?
>A: Yep, that's the one.  However, the Color QuickDraw version is a newer
>   format than the original, includes RGB colors, etc.

Using PICT format was the most convenient, given the time constraints of
getting these demos ready for the Mac II intro.  Also, we has a couple of
programs that read in images, and PICT was the easiest way for them to
share files.  The PICT files we used were exactly like MacDraw PICT files,
except that they used the type 2 picture opcodes, since type 1 pictures
don't support RGB color and pixMaps.

System 4.1, however, contained a patch to DrawPicture that would interpret
type 2 pictures correctly on a non-Mac II, so the color images can be read
in by standard MacDraw.

There is one catch, however, with the original image files.  We made 2
mistakes in writing out the color images that prevent this from actually
happening.  First is that we did not divide up the picture into pieces and
add the appropriate MacDraw picture comments.  Second, we used the wrong
kind of color table in the file.  (There are pixMap color tables and device
colorTables.  Only pixMap tables are interpreted by the System 4.1 patch.)

I have since modified ATG-Paint to write out the pictures properly, and
MacDraw will read the new files quite nicely.  The end result is the same
as if you displayed them on a 1-bit deep screen.

-- 
Larry Rosenstein

Object Specialist
Apple Computer

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