2003.11.17 09:28 "[Tiff] tiff2pdf contribution", by Ross Finlayson

2003.11.21 13:06 "[Tiff] tiff2pdf contribution", by Leonard Rosenthol

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...


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