1993.08.20 01:22 "help on TIFFReadRGBAImage", by Yip Chi Lap
Hello,
I have written a small program to open a TIFF file, read it using TIFFRGBAImage, and then dump the image out byte by byte in hex. I found that the scanline order seems to be reversed.
I scanned archive.May2593-Aug1893 and found only one reference to this function. I use libtiff v3.21 BETA compiled on an multiprocessor sun (`mach`=sparc, `arch`=sun4). The program and the pnm file used to create the tiff file is attached below. Thanks for your help in advance.
Regards,
Beta.
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
#include <iostream.h>
#include <stdio.h>
#include <stdlib.h>
#include <tiffio.h>
#include <tiffcomp.h>
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
int main(int argc,char** argv)
{
TIFF *tif;
int x,y;
char st[80];
unsigned long width, height;
unsigned long *raster;
do
{
cout<<"Filename: ";
cin>>st;
}
while ((tif=TIFFOpen(st,"r"))==NULL);
TIFFGetField(tif,TIFFTAG_IMAGEWIDTH,&width);
TIFFGetField(tif,TIFFTAG_IMAGELENGTH,&height);
raster=(unsigned long *)malloc (width*height*sizeof(unsigned long));
TIFFReadRGBAImage(tif,width,height,raster,0);
cout<<"contiguous: \n";
for(y=0;y<height;y++)
{
for(x=0;x<width;x++)
printf("%.6lX ",raster[y*width+x]);
printf("\n");
}
return(0);
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* the pnm file used
P3
3 5
1
1 0 0 0 1 0 0 0 1
1 0 0 0 1 0 0 0 1
1 0 0 1 1 0 1 1 1
0 0 0 0 0 0 0 0 0
1 1 1 1 1 1 1 1 1
*/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
/* result
contiguous:
FFFFFF FFFFFF FFFFFF // isn't this the last line??
000000 000000 000000 // the RGBA order is right, by the way.
0000FF 00FFFF FFFFFF
0000FF 00FF00 FF0000
0000FF 00FF00 FF0000 // The 0000FF should be (0,0)
*/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/
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