PeachImage
PeachImage.ImageInfo
ImageInfo.IsYcck Property
JPEG/Adobe-specific: whether a 4-component source is really YCCK under the hood (Adobe APP14 transform=2) rather than direct CMYK. Always false for non-JPEG formats and non-YCCK JPEGs. Relevant to DecodeRawYcck — by default, a full decode converts YCCK to CMYK regardless of this flag.
public bool IsYcck { get; init; }