autocrop

Image auto-cropper. This is how it works.

Dependencies

• Python 3
• numpy
• scikit-image
• Pillow

On a debian based distro:

sudo apt-get install python3-numpy python3-pil python3-skimage

Algorithm for content aware cropping

1. Calculate entropy of input image.
2. Based on tresholds check if the entropy gives satisfying results. If not. Blur the input image, calculate entropy and continue using this entropy.
3. Calculate the convolution with summation kernel of fixed size.
4. Find the pixel with max value.
5. Put the pixel in the center and calculate rect with output size.
6. Readjust the rect if the original rect goes outside the boundary of the image.
7. Crop and save image.

Installation

pip install git+https://github.com/tinkerX3/autocrop

or

git clone https://github.com/tinkerX3/autocrop.git
python3 setup.py develop  # this still is beta!

Usage

usage: autocrop [-h] [-s W,H] [-f X1,Y1,X2,Y2] [-i FILE] [-o FILE]

Image cropper

optional arguments:
  -h, --help            show this help message and exit
  -s W,H, --size W,H    ouput image size
  -f X1,Y1,X2,Y2, --featured X1,Y1,X2,Y2
                        coordinates of the important part of the image;
                        X1<X2, Y1<Y2; (0,0) = top-left corner
  -i FILE, --input FILE
                        path/to/the/input/image
  -o FILE, --output FILE
                        path/to/the/output/image

Examples

Crop image to provided size ensuring featured rectangle is included:

$ ./autocrop --size 500x500 \
             --featured 250x100x650x500 \
             --input path/to/image.png \
             --output path/to/output.png

Crop image to size of the featured rectangle:

$ ./autocrop --featured 250x100x650x500 \
             --input path/to/image.png \
             --output path/to/output.png

Crop image to provided size by automatically determining the most important features.

$ ./autocrop --size 500x500 \
             --input path/to/image.png \
             --output path/to/output.png

Also determine the size of important part automatically.

$ ./autocrop --input path/to/image.png \
             --output path/to/output.png