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.TH GENERATEKEYS 1 "MAY 2004" autopano-sift "User Manual"
generatekeys \- Generate SIFT keypoints from an image file
Generate SIFT key descriptors for an image. It reads in the image file,
finds SIFT keypoints for descriptive image locations and outputs the SIFT
descriptors to the keyfile. The image is internally doubled in size, as this
increases the number of keypoints found. If you do not want this behaviour or
want to downscale the picture, see the downscaleResolution option. The
resulting keyfiles can be processed by the other utilities in the
The image file name that will be read in and processed. It can be in any
format readable by the GDK pixbuf loaders. Usually that includes JPEG, PNG and
The name of the keypoint XML file to generate. When ".gz" is used at the end
of the filename, the file is transparently compressed using the gzip
.BR gzip (1)
An optional integer width and height limitation. If given, the input image is
downscaled so its larger dimension matches the given size in pixels.
The smaller the downscale resolution, the smaller the memory
requirements, but also less keypoints are found. In case no downscale
resolution is given, the image is doubled in size prior to processing, which
leads to substantly more keypoints. If you use 0 as downscaleResolution you
can switch this behaviour off and the original image is used without applying
The memory requirements are quite big. If you have 256Mb of ram, you should go
with a 700 downscale resolution, if you have 512Mb 1300 is a good value.
Sebastian Nowozin <nowozin at cs dot tu dash berlin dot de>
.SH "SEE ALSO"
.BR autopano-complete (1),
.BR autopano (1),
.BR autopanog (1),
.BR showone (1),
.BR showtwo (1)