background color when exporting
kalden
Global Mapper User
I am georeferencing some image files into a UTM projection. After georeferencing, the source image is skewed a bit, with the current background color used to make the image square.
Is there anyway to make this background color transparent? When I display a high res map over a low res map, I would rather see the low res imagery than dead pixels from the high res file.
Thanks
Is there anyway to make this background color transparent? When I display a high res map over a low res map, I would rather see the low res imagery than dead pixels from the high res file.
Thanks
Comments
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Are you exporting the files after geo-referencing or just keeping them in the main map view? I would expect the border to be added when exporting if the image is not rectangular in the export projection. You can have this marked as transparency for some formats though, like GeoTIFF, ECW, JPEG2000, or PNG. If you are just referencing into the main view I would not expect any additional pixels to be added.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
I am exporting into a geotiff file. How do I mark the additional pixel data transparent?
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If you are exporting using the File->Export Raster->Export GeoTIFF menu command there is an option to check to make the background pixels transparent.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
Hi Mike,
We have a similar problem, we have a 4 band image, and when we cut the image and export it we have data in black, we check the option to make the additional data transparent but that generates another band in the image, and we end up having a 5 band image.
All the transparent data goes to the 5th band.
Can you help us. -
You have to add an additional band for the alpha channel in order to mark some of the pixels as transparent. You still have 4 data bands in the output, then an additional alpha channel band used to indicate pixel validity. There really isn't a way around though if you need to have pixels marked as invalid.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
global_mapper wrote: »If you are exporting using the File->Export Raster->Export GeoTIFF menu command there is an option to check to make the background pixels transparent.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com
I have the same problem. I've been exporting as a JPG, which doesn't even give you this option, instead of JPG2000. However, if I check the box to make the background pixels transparent, I can't view them in ArcView. If I don't check the box to make the background pixels transparent, I can view them in ArcView. -
The JPG format doesn't support transparency. The JPG2000 format does support an alpha channel, but not all applications support JPG2000 files with transparency (like apparently your version of ArcView). Can you use GeoTIFF? The alpha there is more widely supported, although the files are obviously larger, but you can use JPG-in-TIFF compression with a GeoTIFF.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Guru
gmsupport@bluemarblegeo.com
http://www.globalmapper.com -
Hi
I imported GeoTiff images (with background pixels) and tried to export PNG with background pixel transparent in batch converter. The PNG images still have a black background pixels... Can anyone please help with this?
Thank you in advance
Tai -
What version of Global Mapper are you using? Did you try the same export from the main UI instead of the batch converter? If so, did it work?
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