LibTiff Mailing List
TIFF and LibTiff Mailing List Archive
September 2003
Previous Thread
Next Thread
Previous by Thread
Next by Thread
Previous by Date
Next by Date
Contact
The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems
Thread
2003.09.18 13:09 "Stripsize when writing as scanlines (and huge image flipping).", by Frank Warmerdam
Väinö Järvelä wrote: > Hi, > > > How does libtiff write images with no TIFFTAG_ROWSPERSTRIP set and > written using TIFFWriteScanline? I wanted to have random access to these > files for flipping rows (first row to last etc.) so i tried using 1 > row/strip but it was _really_ slow and the file sizes were big. > > Do you have any ideas how i could implement this? > > (The images are too big to be read in the memory at once so i am reading > them scanline at a time as it seemed appropriate because i'm also doing > some modifications on the scanlines.) > > I thought about reading scanline at a time and writing out as strips > (writing as stripes smaller than the picture should work with > random-access, right?). Väinö, Using ROWSPERSTRIP of 1 for this purpose seems quite reasonable. I don't see why it would be slow or produce files any larger than normal. Perhaps you could make an example of the file produced available? Note that some compression types do not work well with 1 row per strip. I was assuming uncompressed. 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