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TIFF and LibTiff Mail List Archive

Thread

2003.05.21 21:24 "Win32 libtiff calling convention", by Khouri Giordano
2003.05.22 07:43 "Re: Win32 libtiff calling convention", by Andrey Kiselev
2003.06.26 21:08 "Bug located in Sam Leffler's thumbnail.c", by Robert S. Kissel
2003.06.27 20:00 "Re: Bug located in Sam Leffler's thumbnail.c", by Andrey Kiselev
2003.07.11 19:22 "grey scale conversion", by cthomas
2003.07.11 23:29 "Re: grey scale conversion", by Scott Weber

2003.07.11 23:29 "Re: grey scale conversion", by Scott Weber

Just a guess here but...

I think the Kodak image control uses DirectX, so it can map directly to the screen memory. I have played with similar problems.

If your interested, I'll send you my C++ class which I use to unpack and display TIFFs. It's uses StretchBLT. It's used inside an simple MFC program.

I don't want to inundate the list with OS specific code...

-Scott Weber

Newbie questions here, thanks for your patience.

Setup:
----------
Windows/VS6

I'm using tifflib to open G4fax images (decoding each scanline using TIFFReadScanline)

Then I'm memcopying each decoded scanline output from TIFFReadScanline and appending to a large 1 dimensional buffer.

Then I'm calling createbitmap and pointing that to my large buffer to display on screen.

Problem:

  1. Above works but is much slower than the Kodak/Wang "Imaging" program found on Windows.
  2. Any ideas how they do it?
  3. Any faster calls to decode the entire image?
  4. Any faster calls to display the image?
  5. Can anyone point me to some sample C/C++ code that BLT's to screen?
  6. When I go to make proxies (scaling of the image) I'd like the option of scaling in greyscale. (Kodak/Wang Imaging does this almost instantly) How can I do this on my large uncompressed buffer of B&W 1 bit data? Is there a tifflib call that will perform greyscale scaling?
  7. Thanks very much for your time.

Chris Thomas

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