2008.01.21 19:38 "[Tiff] How to clip an image with LibTiff", by

2008.01.22 10:24 "Re: [Tiff] How to clip an image with LibTiff", by Gerben Vos

We deal with faxes in standard mode (204X98 dpi) or fine mode (204X198 dpi) saved with compression of type G3 1D.

I need to write a utility that clips the first X rows (pixel) from the top of the tiff image and last X rows from the bottom of the tiff image. We will save it to a new tiff image with G3 compression in the height of 2X pixels. The first X rows will be the top of the new image and the last X rows will be the bottom of the image. The operation to clip the image, should not alter the image nor do any thing that would damage the image.

Is it doable using libtiff on Unix? Any help and direction will be highly appreciated. Doable using other open source libraries?

Because you know in advance that the input TIFFs will be strip-based (instead of tile-based) and black-and-white, this is quite easy to do with libtiff.

You'll get something like this (this is more pseudo-code than real code, error checking has been omitted):

TIFF *in = TIFFOpen("input.tif", "r");

TIFF *out = TIFFOpen("output.tif", "w"); // Maybe read some headers from "in" to check validity?

uint32 height;
if (height < 2 * x) {
        // error out
uint32 linesize = TIFFScanlineSize(in);
tdata_t scanline = _TIFFmalloc(linesize);

// Write necessary headers to "out".
TIFFSetField(out, ...);


for (uint32 i = 0; i < x; ++i) {
        TIFFReadScanline(in, i, scanline, 0);
        TIFFWriteScanline(out, i, scanline, 0);
for (uint32 i = height - x; i < height; ++i) {
        TIFFReadScanline(in, i, scanline, 0);
        TIFFWriteScanline(out, i, scanline, 0);


Read the documentation for the exact headers you need to write. Also look at the included utility programs for inspiration. Obviously, I haven't tested any of the above code and give no guarantees whatsoever.

Gerben Vos.