How to remove other color line in graph ?

Dear All,

I am going to find the way to remove other color line in a image

I try to use threshold but it is not working.

for example this figure bellow. I want to remove red line and keep blue line

Could anyone help me ?

Thank and Regard!

[Walter Roberson]

Are you starting from an image, or are you starting from a current plot, or are you starting from a .fig file?

[Jenifer NG]

I am starting from an image not a .fig

Answer 1

[Walter Roberson]

filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1092850/image.png';
rgb = imread(filename);
mask = rgb(:,:,1) > 128 & rgb(:,:,2) < 200;
newrgb = rgb;
newrgb(repmat(mask,1,1,3)) = 255;

imshow(rgb)

imshow(newrgb)

You might want to make some subtle cleanup.

[Jenifer NG]

Thanks you,

It work !

I learned new function repmat() from your answer

Answer 2

[Mandar]

I understand that you want to remove one of the lines from the plot.

As a workaround, please use the 'Property Inspector' to delete the plots/lines. Refer to the link below to for more details.

• link: https://www.mathworks.com/help/matlab/ref/propertyinspector.html

[Jenifer NG]

Hi Mandar,

Thanks so much for your information. But I want to remove red line from an image not a .fig.

Sorry for my explaination in question not clear