2003.07.11 19:22 "grey scale conversion", by Christopher Thomas

2003.07.11 19:22 "grey scale conversion", by Christopher Thomas

Hello all,

Newbie questions here, thanks for your patience.


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.


1) Above works but is much slower than the Kodak/Wang "Imaging" program found on Windows.
Any ideas how they do it?
Any faster calls to decode the entire image?
Any faster calls to display the image?
Can anyone point me to some sample C/C++ code that BLT's to screen?

2) 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?

Thanks very much for your time.

Chris Thomas