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2003.11.21 13:06 "tiff2pdf contribution", by Leonard Rosenthol
At 11:59 PM -0800 11/19/03, Finlayson, Ross wrote: > Again, trasnforming the CTM, Current Translation (Transformation?) > Matrix, is probably a more direct route, but if the output format > didn't have a CTM, for example as TIFF doesn't, then functions to > orient the data would be useful to fully implement > TIFFReadRGBAOriented, for example. > > Also, to do matrix math I would have to study for days or at least > hours before I came across the right equations, although as we are > talking about right angles sine and cosine are 0 and +-1. For the basic cases, it's not that bad - and the algorithms are well defined and available online... > Most programs use either top-left or bottom-left. I'm kind of > unclear at the moment but I think PDF uses a bottom-left coordinate > matrix. Yes, PDF/PS uses bottom-left origin (though you can change it if you really want to, but it just makes things harder). > The XObject image that is the raster element in PDF is however > filled top-left, in the same way as the default TIFF orientation. The data is filled in top/left - or really just the standard order of the pixels. HOWEVER, when that XObject is placed into the PDF page, it's location/position is given based on the bottom left of the image. > When sending the output to something like PDF, where we might be > using the CTM transform and let the PDF browser do the lifting, I'm > wondering about the Rotate parameter of the Page structure. You could also use the page's Rotate parameter for your sample utility since it only places one image per page - that would work fine. > It says to set Rotate to /90 /180 or /270 if I recall correctly > (IIRC) and that the page would be rotated thusly in viewing and > printing mode. See, I don't want to use that because the only > reason to rotate the page is to print it portrait nd view it > landscape for ledgers. That's one use for /Rotate... Leonard -- --------------------------------------------------------------------------- Leonard Rosenthol <mailto:leonardr@pdfsages.com> Chief Technical Officer <http://www.pdfsages.com> PDF Sages, Inc. 215-629-3700 (voice) 215-629-0789 (fax)