PA Explorer: Terrabyte Image

The Terrabyte images are extractives from Landsat Thematic Mapper images through the SpectraPlex process. This process does not permit the full restoration of the original scene. The SpectraPlex process takes multiple bands of original image data and compresses them to 255 cluster units using isodata as a cluster mechanism. The result of the process is an image layer of cluster numbers with an accompanying table of band means by cluster number. Color rendition: the shade set is LANDSCOP Portrayal (landscape directed spectral composite portrayal). Total of the visible bands is blue, total of the infrared bands is green, total of all bands modified to help distinguish conifers is red. The images have been converted to ArcInfo Grid coverages, exported and transferred to compact disk. The original SpectraPlex images are approximately 54 megabytes and extend over the Pennsylvania borders. The images on the Terrabyte Images cd-rom have been clipped to the borders of Pennsylvania and cut by county in Pennsylvania.