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

2008.01.22 23:59 "Re: [Tiff] Re: Tiff Digest, Vol 44, Issue 8, Cropping faxes", by Andy Cave

Hi Richard,

I don't think that tiffcrop will do what Erez wants - I think you mis-read his request. He doesn't really want to clip the 'input' image, but extract the first X rows from it and append the last X rows from it into a new image that is 2X high.

You can do that with libtiff with a bit of programming - if all his images are 1 bit he can use the lower level APIs to extract each scanline one at a time and using a simple counter write the first X, ignore the next height-2X and write the final X to a new file.



----- Original Message -----

1. How to clip an image with LibTiff (Erez.Har-Tal@Walgreens.com)

>> Tiffcrop was written to handle just this sort of thing. It is in the

>> utilities section of recent releases and/or in CVS. Read the man page or >> type tiffcrop --help to see all the options.

Richard Nolde, tiffcrop author

>> ----------------------------------------------------------------------
>> Message: 1
>> Date: Mon, 21 Jan 2008 13:38:09 -0600
>> From: Erez.Har-Tal@Walgreens.com
>> Subject: [Tiff] How to clip an image with LibTiff
>> To: tiff@lists.maptools.org
>> Message-ID:
>> <OFFC203445.FE96EEE5-ON862573D7.006ADF71-862573D7.006BDDBF@walgreens.com>
>> Content-Type: text/plain; charset=US-ASCII

Please excuse me if I am new to libtiff, so any help would be appreciated.

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?