GeoExpress - Knowledge Base Articles

A060310 - Valid image data obscured by overlapping nodata region

Products:

GeoExpress

Summary:

When geographically rectified images are mosaicked, nodata overlaps valid data in adjacent images causing data to be obscured in the output MrSID image.

Cause:

The nodata area is not being handled by an alpha channel or assigned a transparency value.

Solution:

The mosaic must be encoded again using the Alpha settings for MG4 output or the Transparency and Background settings for other output formats. To find these settings:

1. Select Encode Options from the Options menu. The Encode Options dialog appears.
2. For MG4 output select the Alpha tab. For other output formats select the Transparency tab.

This article was last updated or verified on 12 October 2012.