Re: several messages
- To: mathgroup at smc.vnet.net
- Subject: [mg31340] Re: several messages
- From: "P.J. Hinton" <paulh at wolfram.com>
- Date: Mon, 29 Oct 2001 02:23:24 -0500 (EST)
- Organization: "Wolfram Research, Inc."
- Sender: owner-wri-mathgroup at wolfram.com
On Fri, 26 Oct 2001, Kari Krueckl wrote: > I am a Mathematica beginner and am having a little trouble. I am > scanning 12-bit images that are being converted to 16-bit grayscale > TIFFs. I need to read the 16-bit TIFF files in Mathematica. I realize > that this is not a supported format and I am not concerned about > displaying the image in Mathematica. I only need to some how import and > manipulate the 16-bit grayscale data from the file. Is there any way to > extract the data array? Or directly read the file into Mathematica? On Sat, 27 Oct 2001, Tomas Garza wrote: > Not a supported format? See the Help browser under "Import". TIFF > appears there as one of the supported formats (unless, of course, you > are using an older version of Mathematica, where "Import" had not been > implemented) . The following information is valid for Mathematica version 4.0 and later. The Mathematica TIFF import function is capable of reading TIFF images that comply with the revision 6 standard as published by Adobe and its predecessor Aldus. The standard only provides for an eight-bit grayscale tag, so 16-bit grayscales are a proprietary extension that cannot be read. A possible workaround is to configure the generating application to save the data either as a portable pixmap (PPM) or a 24-bit color TIFF. Mathematica can read both of these formats with the Import[] function. This will result in rasters of RGB values. One can then use a dithering function to collapse down the RGB color into a single grayscale value. -- P.J. Hinton User Interface Programmer paulh at wolfram.com Wolfram Research, Inc. Disclaimer: Opinions expressed herein are those of the author alone.