Mastering pandas - Second Edition

Selecting only one channel

As we saw earlier, the third dimension denotes the RGB channel. Hence, to filter all the pixels in one channel, we should select all the pixels in the first two dimensions and only the channel of interest. Also, the indexing in Python starts from 0, thus 0 represents red, 1 represents green, and 2 represents blue. Keeping these in mind, let's have a look at the snippets to select the red, green, and blue channels of an image.

The snippet to select the red is as follows:

img_r=img[:,:,0]plt.imshow(img_r)    

The following is the output:

Image pixel array made of selecting only pixels in the red channel visualized as ...