Georeferenced TIFF question...

BlakeWallace · ‎02-10-2012

Need a little help. I'm currently putting together a digital archive of some old 1927 maps. I've scanned all of the maps in (saved as JPEGS) and have georeferenced them all to the road shapefile. Heres the problem: I need a seamless map for this archive to be effective and due to the rectification ArcMap displays the TIFFs with the surrounding pixels classified as "NO DATA" in black. Is there a way to get rid of this black area or make it transparent? I've been doing research for about 2 hours and haven't come up with anything yet.

PrasantaBhattarai · ‎02-10-2012

There are a few ways to get around it.

1. From Layer Properties > Symbology > Check on Display Background Value: (R,G,B) 0,0,0 as NoColor.
The down side of this is, if you have a valid pixel of RGB value 0,0,0 within your image, it will also be set to NoColor. Also, sometimes your bordering pixel values are not always 0,0,0. In this case you will see noise of random black pixels.

2. If you have (or create) boundary file for each raster (excluding black pixels), you can use Clip raster tool. Make sure you check on the "use input feature for clipping geometry" option. This way, whatever is outside the clipping feature will be set to NoData.

3. If you have Editor/Info license, you can also explore the option of storing your images inside a Mosaic Dataset. You can then recalculate Mosaic dataset footprints based on the radiometric values using the Build Footprints tool.

BlakeWallace · ‎02-13-2012

There are a few ways to get around it.

1. From Layer Properties > Symbology > Check on Display Background Value: (R,G,B) 0,0,0 as NoColor.
The down side of this is, if you have a valid pixel of RGB value 0,0,0 within your image, it will also be set to NoColor. Also, sometimes your bordering pixel values are not always 0,0,0. In this case you will see noise of random black pixels.

2. If you have (or create) boundary file for each raster (excluding black pixels), you can use Clip raster tool. Make sure you check on the "use input feature for clipping geometry" option. This way, whatever is outside the clipping feature will be set to NoData.

3. If you have Editor/Info license, you can also explore the option of storing your images inside a Mosaic Dataset. You can then recalculate Mosaic dataset footprints based on the radiometric values using the Build Footprints tool.

Thank you very much for the awesome reply! Appreciate it very much