On Thursday 12 January 2006 10:47 am, Cory Papenfuss wrote: snip >So QImage is effectively > > remapping the 16 bit/channel image as an 8 bit/channel image. > > This would explain my previous post about linear vs. > gamma-corrected input. The linearly-derived profile was much worst fit > and exhibited the banding. I (wrongly) assumed that because lprof could > now load TIFFs via the TIFFio and didn't complain on the 16-bit data, that > it actually *used* the deeper color. > snip
> Can it be read-in via libtiff directly? Just a WAG on my part... > I haven't looked at the code at all. > I could use libtiff directly if I only wanted to support tiff files. I would rather use a library that generalizes this so that other file types are supported. There were lots of good ideas about possible way to approach this. I would like to thank Cory, Alastair, Boudewijn, Bob and Andrew for their ideas. I also found a couple of other libraries by searching the net. After looking things over I am initially leaning toward VIGRA. It looks like it will handle images of practically any bit depth (up to float for each channel) and in a wide range of file types (tiff, png, jpeg, gif ....) with the correct libraries installed. It is also portable across many platforms. And I think I read on the Hugin list that it will handle HDR images. It appears to do everything I need which is not that difficult (open the file and give random access to pixel RGB channel values). So I only need about 2% of what it is capable of. It is being actively maintained and is available for my distro. I also currently have at least two apps on my system that are using it. I have not started coding yet. But my initial look at the code indicates that this should not be too difficult as there are appear to be 3 places where I need to add/change code to implement this and it looks like in total I may have to add/change less then a dozen lines of code. But I may find that I am totally off the mark and it may be way more difficult than I currently think it is. In any case it is time to start coding. Hal ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
