CODEWITHSUNDEEP
pythonimageopencvadditionpixel
Yehadska
Yehadska

Reputation: 63

Add pixels in python opencv?

For example, I want to count and add the pixels between 100 and 255 from an image. I was thinking with two For.

rows,cols,bands=imgbgr.shape

for i in range(rows):
     for j in range(cols):
         for k in imgbgr[i,j]:
             if 100<=k<=255:
                 #print imgbgr[i,j]
                 suma = np.sum(img[i,j])

print suma

Upvotes: 1

Views: 1443

Answers (1)

Jashandeep Sohi
Jashandeep Sohi

Reputation: 5153

Since OpenCV returns numpy arrays, you can use boolean slices to get the job done quicker:

>>> import numpy as np
>>> img = np.random.randint(0, 255, (3, 5, 5))
>>> img
array([[[236, 205, 246,  94, 224],
        [ 28, 143, 159, 167,  54],
        [247, 196, 107, 166,  74],
        [194,  97, 219, 104,  15],
        [143, 105, 107, 218, 240]],

       [[ 54, 225, 231,  35,  39],
        [223,  54,   0, 141,  47],
        [ 69,  20, 222, 244, 143],
        [ 34,  60, 174, 155, 243],
        [173,  35, 173,  32, 246]],

       [[229, 247, 102,  47, 208],
        [201, 182, 172, 247, 171],
        [ 86,  76, 182, 144,  58],
        [155, 243,  37, 220,  75],
        [171, 251,  60, 216,  43]]])
>>> cond = (img >= 100) & (img <= 255)
>>> cond
array([[[ True,  True,  True, False,  True],
        [False,  True,  True,  True, False],
        [ True,  True,  True,  True, False],
        [ True, False,  True,  True, False],
        [ True,  True,  True,  True,  True]],

       [[False,  True,  True, False, False],
        [ True, False, False,  True, False],
        [False, False,  True,  True,  True],
        [False, False,  True,  True,  True],
        [ True, False,  True, False,  True]],

       [[ True,  True,  True, False,  True],
        [ True,  True,  True,  True,  True],
        [False, False,  True,  True, False],
        [ True,  True, False,  True, False],
        [ True,  True, False,  True, False]]], dtype=bool)
>>> img[cond]
array([236, 205, 246, 224, 143, 159, 167, 247, 196, 107, 166, 194, 219,
       104, 143, 105, 107, 218, 240, 225, 231, 223, 141, 222, 244, 143,
       174, 155, 243, 173, 173, 246, 229, 247, 102, 208, 201, 182, 172,
       247, 171, 182, 144, 155, 243, 220, 171, 251, 216])
>>> img[cond].sum()
9360

Upvotes: 1

Related Questions