CCV

Chicken scheme egg with bindings for ccv, a computer vision library.

Note that you will need to fetch the git submodules in this package. In addition this egg compiles ccv with options that require libjpeg, libpng, gsl, fftw3, and cblas. ccv takes a very long time to compile.

API

(read-image image-filename)

(read-greyscale-image image-filename)

(write-image image filename)

Read and write images, return #f on failure. The former always produces a color image.

(imlib-image->ccv-image image)

(imlib-image->ccv-greyscale-image image)

These provide imlib intergration, see the imlib egg for how to use it. Note that imlib always stores images in color so the latter call will always convert the image.

DPM

(load-dpm-mixture-model filename)

Load in a DPM model. Returns #f when the file does not exist, a ccv assertion failure happens if the file does not contain a model.

(make-dpm-detection x y w h confidence)

(dpm-detection-x detection)

(dpm-detection-y detection)

(dpm-detection-w detection)

(dpm-detection-h detection)

(dpm-detection-confidence detection)

Create and access DPM detections.

(dpm-detect-object color-image model #!key (threshold 0.6) (interval 8))

Returns a list of detections, does not return part locations at the moment.

SIFT

(make-sift x y octave level scale angle descriptor)

(sift-x descriptor)

(sift-y descriptor)

(sift-octave descriptor)

(sift-level descriptor)

(sift-scale descriptor)

(sift-angle descriptor)

(sift-descriptor descriptor)

Create and access SIFT descriptors detections. A descriptor is a vector of inexacts.

(sift greyscale-image #!key (noctaves 3) (nlevels 6) (up2x 1) (edge-threshold 10) (norm-threshold 0) (peak-threshold 0))

Run sift on an image and return a list of descriptors.

(sift-match image-sift object-sift #!key (threshold 0.36))

A Scheme version of ccv's siftmatch. Given the sift descriptors for an image it attempts to find correspondences to an object's sift descriptors.

SWT

(make-swt-detection x y width height)

(swt-detection-x detection)

(swt-detection-y detection)

(swt-detection-width detection)

(swt-detection-height detection)

Create and access SWT detections.

(swt-detect-words greyscale-image)

Detect text in images, returns a list of swt-detections.

Caching

(ccv-enable-default-cache)

(ccv-disable-cache)

(ccv-drain-cache)

CCV maintains an internal cache to speed up computations. These functions allow you to manage it.

Example =

  (let img (image-load "/tmp/a.jpg"))
  (for-each (lambda (swt)
      (image-draw-rectangle img 
                            (color/rgba 255 0 0 255)
                             (swt-detection-x swt) (swt-detection-y swt)
                             (swt-detection-width swt) (swt-detection-height swt)))
   (swt-detect-words (read-greyscale-image "/tmp/a.jpg")))
  (image-save img "/tmp/b.png")

License

   Copyright 2012 Andrei Barbu. All rights reserved.
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.
   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.