Converting a PDF to pure black and white

[someone01@adobeforums.com]

I'm currently attempting to convert a PDF of any colorspace (RGB, CMYK, Grayscale etc) to black and white.

Currently I'm walking the PDF using Adobe PDFLibrary, separating the contained PDEElements and identifying them (Image, text, etc).

Does anyone have any advice on how to proceed from here? I figure the actual conversion operation will have to be written from scratch, as Adobe doesn't seem to support this. However, I'm having a hard time determining the colors of each object. I suppose I could rasterize everything and convert pixel by pixel, but I'd like to avoid that and preserve vector images and such if at all possible.

Thanks in advance for any help!

[Leonard_Rosenthol@adobeforums.com]

How do plan to describe "black" and "white" in the PDF? There is no "monochrome" colorspace - so are you planning on using DeviceGray, Separation Black or something else?

Once we understand what your final colorspace goal is, then we can point you at solutions.

[someone01@adobeforums.com]

Yes, I'm aware that there is no monochrome colorspace. However, wouldn't it be possible (likely at a very low level) to fetch and modify the colors of elements manually?

I suspect the initial thing to do is convert images to the DeviceGray colorspace and work from there, since black and white are easily defined there, if I understand correctly.

[Leonard_Rosenthol@adobeforums.com]

There are a set of APIs that you can access from the PDFLibrary (and plugins) for color conversion of objects. Look at the ACxxx APIs and then various PDDoc, PDPage, PDElement, etc. depending on what you are working with.

[PDL@adobeforums.com]

You could also define your own DeviceN colorspace with only two color values - white and black. Then using the methods Leonard suggested, convert your document to this colorspace.

[someone01@adobeforums.com]

Thanks guys, appreciate the assistance