On 08 Oct 2001 01:12:09 -0400 Havoc Pennington <hp redhat com> wrote:
Scott Gifford <sgifford suspectclass com> writes:I'm working on an application that deals with extremely large graphics --- it loads in images of forms and lets you type on them. Right now I'm just using a GdkPixbuf, and have run into some of its limitations. A scanned 300dpi form that's 8.5x11 inches is 8.4 million pixels, and with 24bit color, over 25MB of memory! The viewed image is much larger than the screen, and flickers when it is manipulated. And I have to convert PostScript and PDF files into PNGs to edit them. I'm trying to find a straightforward way to reduce memory usage, to allow zooming in and out, and to support PostScript and PDF image formats. Anybody got any pointers?
You can do conversions on-the-fly by spawning (fork/exec) ghostscript or 'convert' from the imageMagick suite from your app.
The code and more information about the project is at: http://www.suspectclass.com/~sgifford/proforma/
Very nice app! Maybe you can show a shrunken image of the form (again made on-the-fly with ImageMagick) where the user can click on a editable area to bring up a dialog (with possibly en enlarged portion of the document?) where they can fill in a value? What if you use pixmaps with a lower colordepth? I'd suspect 8 bits would be sufficient for most forms. Wouldn't that reduce the memory requirement? Roland -- R.F. Smith "I have made this letter longer than usual r s m i t h @ x s 4 a l l . n l because I lack the time to make it shorter" http://www.xs4all.nl/~rsmith/ -- Blaise Pascal
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