OpenCV has quite good performance. It should be sufficient for most cases. To improve performance, you can also use OpenCV together with Intel IPP, which is however a non-free commercial product. If OpenCV detects that IPP is installed it will use it where possible. As a third option you can use IPP directly. IPP was … Read more
I recommend using ImageMagick, which is open source and quite standard for manipulating images on the command line. Watermarking with an image is as simple as composite -dissolve 30% -gravity south watermark.jpg input-file.jpg output-file.jpg With text, it’s a little more complicated but possible. Using the above command as an example, a Bash command for doing … Read more
Here are some examples of a different (loop free) way to work with blocks: import numpy as np from numpy.lib.stride_tricks import as_strided as ast A= np.arange(36).reshape(6, 6) print A #[[ 0 1 2 3 4 5] # [ 6 7 8 9 10 11] # … # [30 31 32 33 34 35]] # 2×2 … Read more
Since tesseract 3.02 it is possible to specify multiple languages for the -l parameter. -l lang The language to use. If none is specified, English is assumed. Multiple languages may be specified, separated by plus characters. Tesseract uses 3-character ISO 639-2 language codes. An example: tesseract myscan.png out -l deu+eng
scipy.misc.imread() will return a Numpy array, which is handy for lots of things.
GIMP apparently uses a very simple algorithm for automatic white balancing. http://docs.gimp.org/en/gimp-layer-white-balance.html The White Balance command automatically adjusts the colors of the active layer by stretching the Red, Green and Blue channels separately. To do this, it discards pixel colors at each end of the Red, Green and Blue histograms which are used by only … Read more
I just managed to tell ImageMagick about the fonts on my OSX system like this: # Make a new directory for ImageMagick local settings and cd into it mkdir ~/.magick cd ~/.magick # Grab script to find all fonts on system and store them in a config file curl -L http://www.imagemagick.org/Usage/scripts/imagick_type_gen > type_gen # Run … Read more
It is unclear in your question whether you want to actually crop out the information that is defined within the contour or mask out the information that isn’t relevant to the contour chosen. I’ll explore what to do in both situations. Masking out the information Assuming you ran cv2.findContours on your image, you will have … Read more
You first create the filter with fspecial and then convolve the image with the filter using imfilter (which works on multidimensional images as in the example). You specify sigma and hsize in fspecial. Code: %%# Read an image I = imread(‘peppers.png’); %# Create the gaussian filter with hsize = [5 5] and sigma = 2 … Read more
Your best bet is to deal with the image in the HSV colour space (see here for rgb – hsv conversion). The colour of skin is pretty much the same between all races, its just the saturation that changes. By dealing with the image in HSV you can simply search for the colour of skin. … Read more