Thanks for the advice regarding using the CTM for applying a transform
the extracted image. I was able to transform the extracted image to
the display image. I also rebuilt our image processing library as a set
DLLs to avoid any possible conflicts with PDFNet.
The extracted image must have same appearance as the displayed image.
next requirement is to apply operations specified by the PDF file to
extracted, transformed image. For example, the PDF may display a
image, while the extracted image is in colour. What is the best method
obtain the properties indicating that such operations (ie. greyscale
conversion) are required?
Are these attributes obtained from Image::GetImageColorSpace() and
Image::GetImageRenderingIntent()? Is it a matter of examining each
value and using it to determine which operations are necessary?
Yes, you can use Image class to obtain the extra information about any
image in PDF, but I am not sure what additional transformations you
need to apply. PDF doesn't dynamically convert images from one color
space to another (e.g. RGB image is not converted to grayscale - unless
you are writing some kind of a specialized PDF processor).
Image::GetImageRenderingIntent() is a hint for Color Management Module
(CMM) when performing color conversion. Unless you are color-converting
images on your end you can probably ignore this parameter.