Output error vector in the grayscale

I have this piece of code:

resRGB = HSVtoRGB(resHSV);

but I have this error:

Input error: please pass as input a vector variable with 3 elements with value in the range [0,1]

How do I have to improve my code?

[Voss]

I'm guessing that resHSV is not in fact "a vector variable with 3 elements with value in the range [0,1]" (or is it?), so what is resHSV?

Also, you may consider using the built-in MATLAB function hsv2rgb to convert HSV colors to RGB.

[Eva Comeni]

HSVtoRGB is like to hsv2rgb and it works.

Then I have:

resH = 2 * atan2(A, B);

resS = 2 * atan2(C, D);

resV = 2 * atan2(E, F);

resHSV is resH; resS; resV. A vector with 3 elements.

If I write:

resRGB = HSVtoRGB

it works, but thi isn't the results I expect.

Answer 1

[Image Analyst]

Why not use the built-in hsv2rgb()

resRGB = hsv2rgb(resHSV);

[Eva Comeni]

Because my professor wants I create this function (hsv2rgb)

If I use hsv2rgb, I havre this error:

Valid colormaps cannot have values outside the range [0,1].

[Image Analyst]

It works. No colormap is used. You must have done something wrong.

rgbImage = imread('peppers.png');
% Convert rgb into hsv:
hsvImage = rgb2hsv(rgbImage);
% Return to rgb by converting hsv to rgb
rgbImage = hsv2rgb(hsvImage);

But if your professor requires you to write your own code (and not turn in our code as your own), then you'd better do that.

[Eva Comeni]

Write:

resRGB = HSVtoRGB(resHSV);

is it the same to

HSVtoRGB = resHSV;

resRGB = HSVtoRGB;

?

[Image Analyst]

No those would do diffferent things and make diffferent assumptions.

resRGB = HSVtoRGB(resHSV);

assumes that HSVtoRGB is a function, and that resHSV is a 3-D array.

While

HSVtoRGB = resHSV;

would take the resHSV array and make a copy of the array in a new array called HSVtoRGB. HSV2RGB should not be an existing function. Then if you do

resRGB = HSVtoRGB;

you're essentially overwriting the original resRGB array with HSVtoRGB array, which is the same thing as overwriting resRGB array with the resHSV array, which is crazy since that array is from a different color space.

[Eva Comeni]

Ok, thank you. So, how I could improve this:

resRGB = HSVtoRGB(resHSV);

?

N.B. HSVtoRGB (this works fine) is like hsv2rgb.

Answer 2

[yanqi liu]

yes，sir，may be check resHSV value，such as

resHSV = [.6 1 1; .6 .7 1; .6 .5 1; .6 .3 1; .6 0 1]

resHSV = 5×3

0.6000 1.0000 1.0000 0.6000 0.7000 1.0000 0.6000 0.5000 1.0000 0.6000 0.3000 1.0000 0.6000 0 1.0000

size(resHSV)

ans = 1×2

5 3

rgb = hsv2rgb(hsv);
surf(peaks);
colormap(rgb);
colorbar

[Eva Comeni]

I have images, not graphs