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2008.03.27 17:43 "Open Tiff File in Read and write mode.", by Jean-michel Frecinat

2008.04.02 10:29 "Re: Open Tiff File in Read and write mode.", by Gerben Vos

2008.03.27 17:43 "Open Tiff File in Read and write mode.", by Jean-michel Frecinat

Hi,
 
I use libtiff 3.8.2 and i have some problems with memory. When I create a
30000x10000 pixels in cmyk, i have to have a lot of RAM memory (about
2-3GB).
 
To create this file, I use this code.
 
unsigned char* raster = (unsigned char*)_TIFFmalloc(width*height*spp);
 
but this method require a lot of memory.
 
I want use this code.
 
unsigned char* raster = (unsigned char*)_TIFFmalloc(width*spp);
 
But my problem, i would open my file in read and write mode to edit and to
process some pixels and after save the scanline into file.
 
Like that :
 
for(unsigned long y=0 ; y<height ; y++)
{
        TIFFReadScanline(input,data,y,0);
        TIFFReadScanline(output,raster,y,0);

       for(unsigned long x=0 ; x< width ; x++)
       {
                for(unsigned short sample = 0 ; sample < spp ; sample++)
                {
                    raster[(width*index+x)*spp+sample] = data[x*spp+sample];
                    ...
                }
       }
       TIFFWriteScanline(output,raster,y,0);
...
 
This method could help me to create large tiff files with only 1GB of RAM
memory.
 
It is possible, can you help me.
 
 
best regards.
 
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