I don't think it's the alpha channel: I think there's a problem in the TIFF import that results in no data being imported into the channels. I've reported it as a possible bug and have uploaded the sample to tech. When you import it using .11 right clicking on the ranges in style leaves them at 0 to 255. Create a data source to the TIF using GDAL and the image appears immediately with range values such as 22 to 241. Manifold imports it with what, at first glance, is the correct projection: NZGD2000 / New Zealand Transverse Mercator 2000 (EPSG:2193) GDAL does not import the projection. Looking at the GDAL metadata, which Manifold reports but GDAL does not, we see a strange metadata tag: <Item name="Corder">PCRL</Item> That's a weird thing to find in a TIFF, since PCRL progression is something associated with a JPEG2000 file, not a TIFF file. Corder is a default setting of the Kanaku library apparently used within the OpenJPEG library that is used within GDAL. My guess is that this image came from JPEG2000 format and was converted into geoTIFF using GDAL. Something about it now, some sort of GDALism, makes sense to GDAL but not to 9. Could be an issue in GDAL, or 9, or both, or it just might be one of those gray areas. In any event, if GDAL can read it but 9 does not, that should be fixed. Regarding projections: 1. Create a data source for the TIF using GDAL. You get a visible image, but no projection. 2. Import the same TIF using 9. You get a projection, but no visible image. 3. Save the projection used by the imported TIF as a favorite coordinate system. 4. Delete the imported TIF. 6. Copy the linked TIF from the data source and paste into the .map project. 7. Assign coordinate system using the previously saved favorite. 8. Compare what you get in a map against a Bing satellite background layer. The georegistration is not bad, but it is offset to the South by about 3600 meters. If we use Repair Coordinate System to create an "alt" version of the coordinate system with false northing set to 9996400, instead of to 10000000, it lines up perfectly. That's just a quick hack, of course, with no explanation why it seems to work ("seems" because I didn't precisely look at pixel alignments in case of wrong pixel size, etc..). But it's a start. PS: Sure wish we had a tag editor built in... be great to have that as a list, but not where it would bloat up the properties dialog, perhaps in a sidecar "tags" table. :-)
|