2007.08.17 14:51 "[Tiff] tiff problems win to mac", by Balint Radics

Dear experts,

I had a working code (32 windows, libtiff 3.7.3) reading Tiff files. I

wanted to use exactly the same on a 64 bit Mac OS X 10.4.10 (cpu powerpc

970) but I get the strange behaviour that while on the windows libtiff

found the pixel values to be 16 bit per sample, on the Mac OS X it sees

them to be 1048576 bits. I don't understand what is going on, please help!

Here is the result of tiffinfo on my tiff files:

TIFF Directory at offset 0x8 (8)
    Subfile Type: (0 = 0x0)
    Image Width: 1242 Image Length: 1152
    Resolution: 72, 72 pixels/inch
    Bits/Sample: 16

    Sample Format: unsigned integer
   Compression Scheme: None

Photometric Interpretation: min-is-black
Smaples/Pixel: 1
Rows/Strip: 1152

    Planar Configuration: single image plane

I attached the minimal c++ code that works on 32 windows but doesn't work

on 64 bit Mac OS X. Maybe I have to use additional flags when compiling

under Mac. I have gcc 4.0.1 (powerpc-apple-darwin8-gcc-4.0.1).

#include <tiffio.h>
#include <iostream>

int main(int argc, char * argv[]){

TIFF *Tif;
int bitspersample;
int bytespersample;
int ImageHeight;
int ImageWidth;
int tmpw;
int tmph;
int out;

Tif = TIFFOpen(argv[1], "r");

  if (TIFFGetField(Tif, TIFFTAG_IMAGELENGTH, &ImageHeight) == 0 ||
      TIFFGetField(Tif, TIFFTAG_IMAGEWIDTH, &ImageWidth) == 0 ||
      TIFFGetField(Tif, TIFFTAG_BITSPERSAMPLE, &bitspersample) == 0 ){
    std::cerr << "error reading some properities of image " << argv[1] <<
std::endl;
    exit(-1);
  }

  std::cerr << "***Bitspersample: " << bitspersample << std::endl;
  std::cerr << "***ImageWidth: " << ImageWidth << std::endl;
  std::cerr << "***Image: " << ImageHeight << std::endl;
  bytespersample = bitspersample/8;

/* unsigned char * buf;
buf = new unsigned char[TIFFScanlineSize(Tif)];

for (int rows = 0; rows < ImageHeight; rows++){
  TIFFReadScanline(Tif, buf, rows);
  for (int cols = 0; cols < ImageWidth; cols++){
    out = 0;
    for (int kk = bytespersample; kk > 0; kk--) {
      out <<= 8;
      out += buf[cols*bytespersample+kk-1]; //here is the pixel value
    }
  }
}

delete [] buf;*/

TIFFClose(Tif);

}

Please, help!

Thank you,

Balint