How can I find saturated pixels in an image?

How can I find saturated pixels in an image?

[Sean de Wolski]

Define: "saturated"

Answer 1

[Matt Tearle]

idx = all(A==255,3); would give you a logical array that is true at all white pixels (in a uint8 representation).

Otherwise, as Sean asks, what do you mean by "saturated"?

[Jan]

Or for a [W x H x 3] DOUBLE array as RBG image: idx = all(A == 1, 3);

Answer 2

[Tim Zaman]

convert to LAB with the RGB2LAB function.. that splits into three components; the dimensions will be [L;A;B]instaed of [R;G;B]... then you could state something like saturation=sqrt(A_component^+B_component^); which will be your level of saturation, then you just set a threshold. more matlab code on that is on http://www.timzaman.nl/?category_name=gen_matlab&lang=en