what is the meaning of "red and green narrow bands filtered by monochromatic filter"

Hii, I want to know what is the meaning of applying "monochromatic filters to R and G channels of RGB images" and how to impliment these filters in MATLAB.

[DGM]

I give up. What does it mean?

Answer 1

[Walter Roberson]

Example:

img = imread('flamingos.jpg');
imshow(img); title('original');

R = img(:,:,1);
G = img(:,:,2);
B = img(:,:,3);

Rmask = R > 200 & R < 240;
Gmask = G > 50;
imshow(Rmask); title('red mask');

imshow(Gmask); title('green mask');

overallmask = cast(Rmask & Gmask, 'like', img);
filtered_R = R .* overallmask;
filtered_G = G .* overallmask;
filtered_B = B .* overallmask;
filtered = cat(3, filtered_R, filtered_G, filtered_B);
imshow(filtered); title('filtered')

[Walter Roberson]

A monocromatic filter is a filter that is applied to only one of the color channels (at at time, anyhow.)

For example, the flamingos image has orange flamingos and pink flamingos, but orange and pink are not pure Red or Green or Blue, and can only be detected as combinations of those colors. If you were to examine only the Red channel, then you would not be able to isolate the orange flamingos. But sometimes there are useful things that can be done if you work channel by channel.

[Manu Gowda]

I got the concept, Thank you for shraing the knowledge.