How to Read the pixels and state what are all the colors that are present in the Image?

I have plotted the graph using geoshow.

I need to read the pixels and validate the data by counting the respective colors.

So, I want to know what are the colors present in the Image. I have checked that with paint picker. But, there are number of colors.

Is it possible to read the image and list the colors in the form of color code RGB?

If possible, kindly help me out of this.

[KSSV]

what data you have plotted? Can you show us the plot?

[Walter Roberson]

Do you want just the list of unique RGB triples? That is quite easy.

Do you want the "color name" for each RGB triple? That is more difficult, but you could start with the over 1500 named colors at https://en.wikipedia.org/wiki/List_of_colors_(compact) and you could read https://blog.xkcd.com/2010/05/03/color-survey-results/ (read it multiple times)

Do you want the named "primary" color for each RGB triple? That is hardest, as we have a very tough time defining exactly where "blue" ends and the next major color starts. Mechanical definitions based upon octant of the RGB color are not very good at aligning with human experience.

[Guillaume]

Jotheeshwar V's comment mistakenly posted as an answer moved here:

I don't need the color name. The color indication in redchannel, greenchannel and bluechannel values. Like 255, 255, 255 for white.

and By the way, it is radar-gram of the ground surface and the plot is

https://drive.google.com/open?id=1AHilH-DD7AlSDxrReZ35ZO-06My-G84M

Regards,

Jotheeshwar

Answer 1

[Walter Roberson]

[uniquergb, ~, groupnumber] = unique(reshape(YourImage, [], 3),'row');
groupcounts = accumarray(groupnumber);

Now the RGB triple uniquergb(K,:) occurred groupcounts(K) times.

[Jotheeshwar V]

Kindly elaborate it. When I follow this code, I am getting the error stated below

Struct contents reference from a non-struct array object.

Kindly help me

[Walter Roberson]

YourImage = imread('peppers.png');
[uniquergb, ~, groupnumber] = unique(reshape(YourImage, [], 3),'row');
groupcounts = accumarray(groupnumber, 1);

[sortedcounts, sortidx] = sort(groupcounts, 'descend');
N = 10;
most_common_rgb = double( uniquergb(sortidx(1:N),:) );
most_common_counts = sortedcounts(1:N);
fprintf('The most common colors are:\n  count @ [r, g, b]\n');
fprintf('%g @ [%g, %g, %g]\n', [most_common_counts, most_common_rgb].' );   %transpose is important

[Jotheeshwar V]

Error using unique (line 104) Unrecognized flag 'row'. Valid flags are 'rows', 'first', 'last', 'stable', 'sorted', 'legacy'.

Error in Count (line 2) [uniquergb, ~, groupnumber] = unique(reshape(YourImage, [], 3),'row');

This is the error I am getting for the above code

[Walter Roberson]

YourImage = imread('peppers.png');
[uniquergb, ~, groupnumber] = unique(reshape(YourImage, [], 3),'rows');
groupcounts = accumarray(groupnumber, 1);

[sortedcounts, sortidx] = sort(groupcounts, 'descend');
N = 10;
most_common_rgb = double( uniquergb(sortidx(1:N),:) );
most_common_counts = sortedcounts(1:N);
fprintf('The most common colors are:\n  count @ [r, g, b]\n');
fprintf('%g @ [%g, %g, %g]\n', [most_common_counts, most_common_rgb].' );   %transpose is important

[Jotheeshwar V]

When I use my image, I am getting the error:

Out of memory. Type HELP MEMORY for your options.

I tried for a small image and that worked out

What should I do for this concern?

and the grid size of my file is, 11521x39842x3