AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2006.01.25 00:22 "[Tiff] 16 bites PIXMAP to 16 bits TIFF in Delphi", by Hans-David Alkenius
2006.01.25 09:20 "[Tiff] Is TIFFWriteEncodedStrip function slow?", by michael Dorrian
2006.01.25 12:45 "Re: [Tiff] Is TIFFWriteEncodedStrip function slow?", by Frank Warmerdam
2006.01.25 15:12 "RE: [Tiff] Is TIFFWriteEncodedStrip function slow?", by
2006.01.25 23:58 "Re: [Tiff] Is TIFFWriteEncodedStrip function slow?", by Chris Cox
2006.01.27 00:20 "Re: [Tiff] 16 bites PIXMAP to 16 bits TIFF in Delphi", by Joris Van Damme

2006.01.25 12:45 "Re: [Tiff] Is TIFFWriteEncodedStrip function slow?", by Frank Warmerdam

On 1/25/06, michael Dorrian <m_dorrian@yahoo.com> wrote:

I am trying to improve performance in my program. I can write out all my image data once using TIFFWriteEncodedStrip and because i only use this once i thought it should be faster than this:

                                    for(row = 0;row < height;height++){
                                          read one line raw data
                                          using TiffWriteScanline write one line of raw data}
but i tested it and writing all bytes only once is actually slower. I thought the function call overhead alone would make the above much slower but it doesn't seem to be. Therefore i conclude that TIFFWriteEncodedStrip function must be very slow. Is this a correct assumption?. Maybe something else is wrong in my code if writing all bytes once should be much faster. I need your opinions.........

Michael,

TIFFWriteEncodedStrip() should in theory be a wee bit faster than TIFFWriteScanline() but the difference should be very minor. The once-per-scanline function call overhead is negligable.

If you are seeing TIFFWriteScanline() being alot faster then I suspect there are other differences coming into play.

Best regards,
--

---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent