← Back to branch summary

~paparazzi-uav/paparazzi/v5.0-manual

« back to all changes in this revision

Viewing changes to sw/ext/opencv_bebop/opencv/modules/python/test/calchist.py

  • Committer: Paparazzi buildbot
  • Date: 2016-05-18 15:00:29 UTC
  • Revision ID: felix.ruess+docbot@gmail.com-20160518150029-e8lgzi5kvb4p7un9
Manual import commit 4b8bbb730080dac23cf816b98908dacfabe2a8ec from v5.0 branch.

Show diffs side-by-side

added added

removed removed

Lines of Context:
sw/ext/opencv_bebop/opencv/modules/python/test/calchist.py
 
1
#!/usr/bin/env python
 
2
 
 
3
# Calculating and displaying 2D Hue-Saturation histogram of a color image
 
4
import sys
 
5
import cv2.cv as cv
 
6
 
 
7
def hs_histogram(src):
 
8
    # Convert to HSV
 
9
    hsv = cv.CreateImage(cv.GetSize(src), 8, 3)
 
10
    cv.CvtColor(src, hsv, cv.CV_BGR2HSV)
 
11
 
 
12
    # Extract the H and S planes
 
13
    h_plane = cv.CreateMat(src.rows, src.cols, cv.CV_8UC1)
 
14
    s_plane = cv.CreateMat(src.rows, src.cols, cv.CV_8UC1)
 
15
    cv.Split(hsv, h_plane, s_plane, None, None)
 
16
    planes = [h_plane, s_plane]
 
17
 
 
18
    h_bins = 30
 
19
    s_bins = 32
 
20
    hist_size = [h_bins, s_bins]
 
21
    # hue varies from 0 (~0 deg red) to 180 (~360 deg red again */
 
22
    h_ranges = [0, 180]
 
23
    # saturation varies from 0 (black-gray-white) to
 
24
    # 255 (pure spectrum color)
 
25
    s_ranges = [0, 255]
 
26
    ranges = [h_ranges, s_ranges]
 
27
    scale = 10
 
28
    hist = cv.CreateHist([h_bins, s_bins], cv.CV_HIST_ARRAY, ranges, 1)
 
29
    cv.CalcHist([cv.GetImage(i) for i in planes], hist)
 
30
    (_, max_value, _, _) = cv.GetMinMaxHistValue(hist)
 
31
 
 
32
    hist_img = cv.CreateImage((h_bins*scale, s_bins*scale), 8, 3)
 
33
 
 
34
    for h in range(h_bins):
 
35
        for s in range(s_bins):
 
36
            bin_val = cv.QueryHistValue_2D(hist, h, s)
 
37
            intensity = cv.Round(bin_val * 255 / max_value)
 
38
            cv.Rectangle(hist_img,
 
39
                         (h*scale, s*scale),
 
40
                         ((h+1)*scale - 1, (s+1)*scale - 1),
 
41
                         cv.RGB(intensity, intensity, intensity),
 
42
                         cv.CV_FILLED)
 
43
    return hist_img
 
44
 
 
45
if __name__ == '__main__':
 
46
    src = cv.LoadImageM(sys.argv[1])
 
47
    cv.NamedWindow("Source", 1)
 
48
    cv.ShowImage("Source", src)
 
49
 
 
50
    cv.NamedWindow("H-S Histogram", 1)
 
51
    cv.ShowImage("H-S Histogram", hs_histogram(src))
 
52
 
 
53
    cv.WaitKey(0)