Corrupt pixels when clipping CMYK TIFF

[nonkeltjebob]

Magick.NET version

Q8 x64 14.14

Environment (Operating system, version and so on)

Linux alpine/Windows 11

Description

Hi,

Clip() on a CMYK TIFF after TransformColorSpace to sRGB produces a noisy artifact band

14.12:

14.14:

Diff:

Steps to Reproduce

using (var img = new MagickImage("input.tif"))          // CMYK TIFF
  {
      img.TransformColorSpace(ColorProfiles.SRGB);
      img.Alpha(AlphaOption.Transparent);
      img.Clip(ClipName);
      img.Alpha(AlphaOption.Opaque);
      img.Resize(Out, Out);
      using var bg = new MagickImage(MagickColors.BlueViolet, Out, Out);
      bg.Composite(img, CompositeOperator.Over);
      bg.Write("clipped.png");
  }

Images

input.tif

[dlemstra]

I am not yet sure what is causing this side effect but because we made some fixes to the clipping path logic you will now need to do this instead:

    img.Alpha(AlphaOption.Transparent);
    img.Clip(ClipName);
    img.Alpha(AlphaOption.Opaque);
    img.RemoveWriteMask();  // this removes the clip mask

In earlier versions you did not have to do this but because we fixed another bug you will now need to do this.

[nonkeltjebob]

Yes, that seems to fix it. Thanks!