Posting a summary in case someone else down the line comes across the same issue.
I discovered that the problem was with my source TIFFs. Most of them were created with 16-bit color depth, and the Java image libraries apparently can't handle that. I converted them to 8-bits per channel (well, really just the one since these were all grayscale) and they all look great now. On Wed, 2008-08-20 at 15:29 -0500, Grimland, Courtney wrote: > I'm using DSpace 1.4, and don't have the option to upgrade at the > moment, so hopefully someone can help me with the older version. > > I'm having a hard time trying to figure out how to make decent-looking > previews and thumbnails. This particular collection I'm working on is > a > bunch of scans of black-and-white photographs, in TIFF format. I've > got > the jai-imageio libraries installed and added TIFF to the JPEGFilter > and > BrandedPreviewJPEGFilter inputFormats. The filter-media script is > creating the thumbnails and previews, but they just look like snow. > > I'm not rally a java person, so after a little Googling I tried > specifying different combinations of interpolation, dithering, and > rendering values in JPEGFilter.java, for example: > > <...> > import java.awt.RenderingHints; > <...> > // now render the image into the thumbnail buffer > Graphics2D g2d = thumbnail.createGraphics(); > g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, > RenderingHints.VALUE_INTERPOLATION_BICUBIC); > g2d.setRenderingHint(RenderingHints.KEY_RENDERING, > RenderingHints.VALUE_RENDER_QUALITY); > g2d.setRenderingHint(RenderingHints.KEY_DITHERING, > RenderingHints.VALUE_DITHER_DISABLE); > g2d.drawImage(buf, 0, 0, (int) xsize, (int) ysize, null); > <...> > > But the resulting previews and thumbnails always look like snow. I > just > don't know where or how to specify a different resampling method. > > > Examples: > > This is actually a JPG scaled down in Gimp, to get the idea of the > original 44MB TIFF: > http://rocky.uta.edu/grimland/images/orig.jpg > > This is the preview JPG crated by MediaFilterManager: > http://rocky.uta.edu/grimland/images/preview.jpg > > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ DSpace-tech mailing list > DSpace-tech@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/dspace-tech ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ DSpace-tech mailing list DSpace-tech@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dspace-tech
