[BUG] CMYK is being saved as RGB on export

[TGS963]

Describe the bug

We employ the oiio library for reading and writing files before and after upscaling images. However, it saves CMYK images as RGB during export, although they appear correct before exporting.

OpenImageIO version and dependencies

OpenImageIO version 2.5.7.0-1 installed from ArchLinux repo

To Reproduce

We use the C++ API for using oiio in our code

The code to save is

std::unique_ptr<ImageInput> in = ImageInput::open(imagepath.c_str());
if (!in)
{
    std::cerr << "Could not open " << imagepath.c_str() << ", error = " << geterror() << "\n";
    errorOccurred = true;
    continue;
}

const ImageSpec &spec = in->spec();
w = spec.width;
h = spec.height;
c = spec.nchannels;

pixeldata = new unsigned char[w * h * c];
in->read_image(0, 0, 0, c, TypeDesc::UINT8, pixeldata);
in->close();

and the code to save image is:

std::unique_ptr<ImageOutput> out = ImageOutput::create(v.outpath.c_str());
if (!out)
{
    std::cerr << "Could not create output image, error = " << geterror() << "\n";
    continue;
}

std::unique_ptr<ImageInput> in = ImageInput::open(v.inpath.c_str());
if (!in)
{
    std::cerr << "Could not read input image, error = " << geterror() << "\n";
    continue; // Handle error appropriately
}
const ImageSpec &inputImageSpec = in->spec();
in->close(); // Close the input image

ImageSpec spec(v.outimage.w, v.outimage.h, v.outimage.elempack, TypeDesc::UINT8);

spec.extra_attribs = inputImageSpec.extra_attribs;
spec.extra_attribs.attribute("XResolution", 300);
spec.extra_attribs.attribute("YResolution", 300);
spec.extra_attribs.attribute("Exif:PixelXDimension", v.outimage.w);
spec.extra_attribs.attribute("Exif:PixelYDimension", v.outimage.h);
std::cout << "\n\nNew Color Space: " << spec.extra_attribs.get_string("ICCProfile:color_space") << "\n\n";

success = out->open(v.outpath.c_str(), spec);
if (!success)
{
    std::cerr << "Could not open output image, error = " << out->geterror() << "\n";
    continue;
}
success = out->write_image(TypeDesc::UINT8, v.outimage.data);
if (!success)
{
    std::cerr << "Could not write output image, error = " << out->geterror() << "\n";
    continue;
}

out->close();

oiiotool code to replicate is

oiiotool output/cmyk_original.jpg --resize 500x333 --metamerge -o cmyk1.jpg

Evidence

The information is there before saving

But after saving the image file

The Original Photo

The processed photo