LibTiff Mailing List
TIFF and LibTiff Mailing List Archive
June 2011
Previous Thread
Next Thread
Previous by Thread
Next by Thread
Previous by Date
Next by Date
Contact
The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems
Thread
2011.06.25 00:27 "Re: 16-bit image", by Leandro Bugnon
The image was made that way intentionally. My problem is that if I have a stack with 2 images or slices, some of the viewers I've tryed define the display range between the min and max of the first image. In the test image, the value 500 is represented in black and 700 in white, so the second image (1000-1400) it's completely white. I cannot scale the image becouse it's for cuantitative microscopy, and the values goes from 0 to 2^14, so if I have a image from 500-700, it have to be almost dark and darker than the second image. I supposed that had some tag missed, but it seems not. The pixel values are correctly saved, the problems seems the visualization info to show them in a scale from 0 to 2^16 ( I can scale from 0-2^14 to 0-2^16 but I cannot scale anything to 0-2^16 becouse I'm distorting the information). Thanks for your answers and sorry for my english 2011/6/24 Chris Cox <ccox@adobe.com> > The min/max sample values are metadata, and don’t affect interpretation > of the file data. > So even if wrong, they shouldn’t cause the symptoms described. > > I do wonder if the byte order of the data might be wrong, and it’s picking > up the low order bits of the image. > > Chris > > > > On 6/24/11 3:50 PM, "Leandro Bugnon" <l.bugnon@gmail.com> wrote: > > Thanks for the quick answer. Here is a test image > > - http://www.filefactory.com/file/cc0b359/n/test1.tif > > > Another thing that cannot understand is that TIFFTAG_SMINSAMPLEVALUE > / TIFFTAG_SMAXSAMPLEVALUE remains in zero value but I changed that in the > code. > > 2011/6/24 Bob Friesenhahn <bfriesen@simple.dallas.tx.us> > > On Fri, 24 Jun 2011, Leandro Bugnon wrote: > > Hi, > I'm getting a 14bit image from a CCD cam, and save it in a 16bit. The > problem is that, if I take only 2 gray > values (greater than zero and less than 2^14), the viewers that I try > (imageJ and irfanview) take them as > zero and max valuo (black and white), they don't show the real color. How > can I fix it? I've tryed the next > tags: > > The values are correctly saved, but it always show a full black and full > white value when there isn't any > zero or 2^16 value. > > > I am not immediately seeing a problem with your tags. Perhaps the pixel > values are wrong, or perhaps this is a problem with these viewers. > > Are you able to post a sample TIFF file somewhere so we can download > it and see how it is constructed? > > Bob > > -- Leandro