On Thu, 16 Aug 2001, Clarence Verge wrote:
> > Why is it that
> > there seem to be so many incompatible BMP formats
> > floating around? It's almost as bad as TIFF!
>
> Not hardly. <g> I also don't know about incompatible BMP formats -
> unless you mean the incompatability of a 1024x768 .BMP with a fixed
> 640x480 display. BMPs are just video memory dumps.
There are 1, 4, 8, or 24 bit BMPs. Hmmm, I wonder
why no 16 bit.
There are compressed (RLE) or uncompressed BMPs. There
are transparent BMPs.
And there seems to be no real standard. From the
O'reilly Graphics File Format FAQ:
(http://www.oreilly.com/centers/gff/gff-faq/gff-faq3.htm#15)
"There is not single document that is the official
'BMP Format Specification'. Instead, BMP information
is spread over several programming references."
Certainly in any kind of "standard" format, if there
is no *single, official* standard, then there will be
multiple standards. Multiple standards mean some viewers
will not see some BMP formats, for instance, the BMPs
that Arachne can't see:
http://wizard.dyndns.org/997967481.zbm
(Yes, the server has the mime type added. That makes
me, what? the 3rd or 4th server in the world to do
this? ;-)
> > (Have you ever tried looking at a patent drawing from
> > the US Patent Office website? What a nightmare!)
>
> I agree 100%. And in this case I would much prefer a compressed .BMP.
I believe they should use something that DOES have a
standard, and an open one at that. In a perfect world, the
patent office would use PNG, and they wouldn't "make them
available" via a time-limited <embed> tag, but would simply
use a standard HTML <a href>.
> > As to what the author intended, I'm sure he intended
> > the land mass to show as pale yellow, since that's what
> > I see in both Acroread 4 and xpdf 0.91
>
> What color you see has as much to do with your video display mode and
> drivers as what the author intended, and nothing to do with Acroread.
> If the author was dumb enough to specify a 24bit color, there is a very
> high likelyhood that almost no one will see the color specified.
> Certainly not in Arachne if the spec. is something like #DCDC93.
> Hicolor is only physically capable of showing 32768 of the 16.7 million
> 24bit possibilities.
Then again, even with 24-bit color specified, it won't
matter if he uses "web-safe" colors such as #ffffcc.
> If you are using a windows 24bit video driver and shoot a .BMP of THAT
> screen, the info WILL be in the file. It will only be an approximation
> if you shoot in 15 or 8 bit color modes.
Except that there is no 15 bit BMP format. ;-)
... hmmm... the fact that I use X in 16-bit mode probably
does mean I don't see all colors *exactly* as intended.
However, I do check "controversial" images with zgv in
console, where svgalib is displaying 24-bit.
> But who has generated the problem here ? Is a 24 bit specific color
> reasonable for a document that isn't a photograph ? Is it important ?
Which problem?
Are you assuming that the pdf author has used 24-bit
color depth? Unless he wants BMP screenshots to render in
only 256 colors, then he MUST use 24-bit color since BMP
has no 15 or 16-bit color mode.
> I really can't say - I can't see the original .pdf (I refuse to use
> the Acrobat reader - needs Windows) -
Actually, I occasionally do use the Acrobat reader, and
I manage to do it without Windows.
> what percentage of the screen
> width was that ? If it had been printed on an 8.5" page would you
> need a magnifying glass ? Maybe it would be better if it was shot
> from a 1024x768 screen ?
Displaying unreadable text at even smaller sizes doesn't
make it more readable.
> > I'm not pushing .PDFs either. I just don't like
> > Microsoft Windows Bitmap images, and would just like to
> > see each format used where it belongs. PDFs for
> > documents which need to be printed out a specific way
> > and BMPs on Windoze.
>
> This last paragraph is my main reason for answering your post.
> BMPs were around long before Windows was invented. They are no more a
> M$ proprietary format than my .DOCs were created by M$ Word. (NOT!!)
> Those b@#$%^ds think they can lay claim to the entire known universe
> just by sticking their flags in the landscape wherever they like. :(
I have no idea who developed the specific header info
prepended to a raw image which transforms it from
"raw screen data" into "Windows Bitmap Image."
>From the google pdftotext version of:
http://www.google.com/search?q=cache:LddMTROxrT8:www.deakin.edu.au/~agoodman/sci204/chapter10.pdf+dib+graphics+format+origins
BMP
The Microsoft Windows Bitmap was derived from the MSP file
format of the (black and white) Paint program in the earlier versions
of Windows. It shares many of the characteristics (both good and
bad) of the PCX format: simple RLE compression, late addition of
24-bit support, and some degree of device-dependence. Supported
by all Windows development environments, it is universally used
(often in conjunction with other formats) as a sort of `lowest
common denominator' by Windows applications.
I'm sure that, like QDOS, Paint was merely something that
Billy Boy scooped up from somewhere else and put his own
name on, but the fact remains that in the historical
context of the desktop computer age, BMP has "always"
been defined as the Windows Bitmap Image format.
- Steve
