Help with Rec601YCbCr to sRGB conversion

[Kargo]

I'm trying to convert a JP2 image in the Rec601YCbCr colorspace to an sRGB JPEG, while also adding some white borders.

Running the following command in the command line produces the result that I want.
magick file3.jp2 -colorspace sRGB -extent 1000x1000 output.jpg

How would I replicate this in code? So far I have been unable to reproduce the extent effect without the background of the output image being pink.

[dlemstra]

What have you tried and did not work?

[Kargo]

This is the result without touching the colorspace

I've done previous colour space conversions (like sRGB to CMYK) by using the SetProfile method.

image.SetProfile(ColorProfile.SRGB);
image.SetProfile(ColorProfile.USWebCoatedSWOP);

There is no built in profile for Rec601YCbCr, so I've downloaded an Rec601 ICC profile here.

image.SetProfile(new ColorProfile(@"\icc\Rec601PAL-v4.icc"));
image.SetProfile(ColorProfile.SRGB);

This gives me the white background that I want, but it also ruins the image's colours.

I can send the problematic image privately, but I'm unfortunately not allowed to post it publicly.

[dlemstra]

The -colorspace sRGB option is the same as image.ColorSpace = ColorSpace.sRGB. Have you tried using that instead? Another option would be to use image.TransformColorSpace together with a profile.

[Kargo]

Thank you, after some more tinkering I got it working by using image.ColorSpace = ColorSpace.sRGB.