AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2008.03.27 17:43 "[Tiff] Open Tiff File in Read and write mode.", by Jean-Michel FRECINAT
2008.04.02 10:29 "Re: [Tiff] Open Tiff File in Read and write mode.", by Gerben Vos

2008.03.27 17:43 "[Tiff] 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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