opencv
set focus to image window opencv
cv2.namedWindow('img',cv2.WINDOW_NORMAL)
cv2.setWindowProperty('img',cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_FULLSCREEN)
cv2.setWindowProperty('img',cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_NORMAL)
cv2.imshow('img', img)
cv2.waitKey()
cv2.destroyWindow('img')
sample images in opencv github repo
https://github.com/opencv/opencv/tree/master/samples/data
see also
[[openFrameworks]], [[Processing]]
Notes on findContours
- Source image is modified by this function.
- Also, the function does not take into account 1-pixel border of the image (it's filled with 0's and used for neighbor analysis in the algorithm), therefore the contours touching the image border will be clipped.
Subtract vs absdiff
Subtract can be useful instead of absdiff if you want only difference when something 'appears or moves' and not when it 'disappears'
Optical Flow
- use Farneback for a dense flow field, (voor een dense flow field met een vector per row/col)
- use PyrLK for specific features (voor feature herkenning. kan objecten volgen)
Thresholding
Various
- http://indranilsinharoy.com/2012/11/01/installing-opencv-on-linux/
- see also: [[cv]]
- matrix set all values to 0:
mat.setTo(0);
- background subtraction: http://www-staff.it.uts.edu.au/~massimo/BackgroundSubtractionReview-Piccardi.pdf
- [[openFrameworks]]
- http://code.google.com/p/cvblob/
- http://docs.opencv.org/modules/imgproc/doc/structural_analysis_and_shape_descriptors.html