Context Mosaics

The PDS data archive for MSL includes mosaics generated by the science team from Navcam data. However, sometimes sequences of single frame images are acquired for the purpose of creating a mosaic without a formal data product being archived. For these cases, we have created mosaics from the single frame images to provide context, and have included them in the MSL AN.

Context mosaics, which are not calibrated science products, are created from Navcam, Mastcam and MAHLI images using Microsoft Image Composite Editor (ICE) software in either perspective or simple horizontal cylindrical projection. Navcam con-text mosaics are created by stitching radiometrically calibrated images and then applying a linear 2% stretch. Mastcam and MAHLI context mosaics use DRCL products as sources. Projection information for the context mosaics is available in the EXIF data that are part of the embedded JPG file header with each mosaic.

Whereas the archive mosaics are created from a priori knowledge of the camera models and pointing information, Microsoft ICE uses well-understood techniques to match overlapping images without such knowledge. It is not unusual to find minor errors in some of the mosaics (both archive and context) because of the large field of view of source images and the mosaics. Most mismatches occur at distances relatively close to the camera.

Context mosaics are incorporated into the Sol summaries and Search results. In addition, a separate list of all context mosaics is available from the Search tab. A built-in mosaic viewer provides pan and zoom support, especially useful with larger mosaics.

Image Composite Editor (ICE) is an advanced panoramic image stitcher created by the Microsoft Research Computational Photography Group. Given a set of overlapping photographs of a scene shot from a single camera location, the app creates high-resolution panoramas that seamlessly combine original images. ICE can also create panoramas from a panning video, including stop-motion action overlaid on the background. Finished panoramas can be saved in a wide variety of image formats, including JPEG, TIFF, and Photoshop’s PSD/PSB format, as well as the multiresolution tiled format used by HD View and Deep Zoom. A load of thanks goes out to Matt Uyttendaele and his team who originally helped us integrate their code into our process. For more information, see: