Revision history [back]

I'm not sure that mask.jpg is grayscale image. Your link is a png with 24 bits depth image (some site change image format).

Now in jpg format I don't think it's possible to use a specific color space. When you use imread wit a jpg file you will get a three channel image : imread("mask.jpg",IMREAD_UNCHANGED )

three channels means B G R. (of course some users can save YUV as a jpg and everything is broken but you cannot know this before display image)

Now your code is wrong :

mask = imread("mask.jpg")>200;
cvtColor(mask, red, COLOR_GRAY2BGR);

because in imread second parameter default value is IMREAD_COLOR

I'm not sure that mask.jpg is grayscale image. Your link is a png with 24 bits depth image (some site change image format).

Now in jpg format I don't think it's possible to use a specific color space. When you use imread wit a jpg file you will get a three channel image : imread("mask.jpg",IMREAD_UNCHANGED )

three channels means B G R. (of course some users can save YUV as a jpg and everything is broken but you cannot know this before display image)

Now your code is wrong :

mask = imread("mask.jpg")>200;
cvtColor(mask, red, COLOR_GRAY2BGR);

because in imread second parameter default value is IMREAD_COLORIMREAD_COLOR and if image is a grayscale image then image will be convert in color.

I'm not sure that mask.jpg is grayscale image. Your link is a png with 24 bits depth image (some site change image format).

Now in jpg format I don't think it's possible to use a specific color space. When you use imread wit a jpg file you will get a three channel image : imread("mask.jpg",IMREAD_UNCHANGED )

three channels means B G R. (of course some users can save YUV as a jpg and everything is broken but you cannot know this before display image)

Now your code is wrong :

mask = imread("mask.jpg")>200;
cvtColor(mask, red, COLOR_GRAY2BGR);

because in imread second parameter default value is IMREAD_COLOR and if image is a grayscale image then image will be convert in color.

mask = imread("mask.jpg",IMREAD_UNCHANGED)