Improper Tiff image generated from RGB888 data - c

Question

I'm trying to convert RGB888 image data to TIFF image. But code generates improper image.
I'm reading the RGB data from text file.Here is the output image
the black region shouldn't be there it seems that code is making low RGB values to zero.
I'm creating tiff image without alpha channel.Please help me comprehend the issue.
TIFF *out= TIFFOpen("new.tif", "w");
int sampleperpixel = 3;
uint32 width=320;
uint32 height=240;
unsigned char image[width*height*sampleperpixel];
int pixval;
int count=0;
FILE *ptr=fopen("data.txt","r");
if (ptr!=NULL)
{
while(count<width*height)
{fscanf(ptr,"%d",&pixval);
*(image+count)=(unsigned char)pixval;
count++;}
}
printf("%d\n",count);
TIFFSetField(out, TIFFTAG_IMAGEWIDTH, width); // set the width of the image
TIFFSetField(out, TIFFTAG_IMAGELENGTH, height); // set the height of the image
TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, sampleperpixel); // set number of channels per pixel
TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 8); // set the size of the channels
TIFFSetField(out, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT); // set the origin of the image.
// Some other essential fields to set that you do not have to understand for now.
TIFFSetField(out, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
TIFFSetField(out, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);
tsize_t linebytes = sampleperpixel * width;
unsigned char *buf = NULL;
//if (TIFFScanlineSize(out)<linebytes)
// buf =(unsigned char *)_TIFFmalloc(linebytes);
//else
buf = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(out));
TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, TIFFDefaultStripSize(out, width*sampleperpixel));
uint32 row ;
//Now writing image to the file one strip at a time
for (row = 0; row < height; row++)
{
//memcpy(buf, &image[(height-row-1)*linebytes], linebytes); // check the index here, and figure out why not using h*linebytes
memcpy(buf, &image[(row)*linebytes], linebytes);
if (TIFFWriteScanline(out, buf, row, 0) < 0)
break;
}
TIFFClose(out);
if (buf)
_TIFFfree(buf);

Answer 1

I found your example at this tutorial. Since you are not the original author, you should always post a link to help others and avoid plagiarism.
The example works great except the part you added. To read file into byte array, use this instead (after you read what fread does):
fread(image, 1, sizeof image, ptr);
in your original code, you omitted sampleperpixel
while(count<width*height*sampleperpixel) ...
so you read only one third of the image.