Hi All, I have a rectified TIFF image from ArcMap8x. The image was rectified using 4 corners (UTM values) from the original raw TIFF image (a scan (150 dpi) of a NTS Topo Mapsheet). It was rectified in UTM Nad 27. I wanted to reproject the image in World Mercator Nad 27, with the Central Meridian at -96 West.
The original TIFF image (256-color with 8.5m pixel) was 12mb in size. When saved as .ERS file, the size went to 30+mb. The newly rectified (Mercator 96) image was nearly 4 times (120MB) the .ERS file. The newly saved TIFF image (256-color) (Mercator 96) was 75 MB, while maintaining the original pixel size (8.5m) value of the original TIFF image. I am uncertain why the file sizes of the new .ERS file (and resulting TIFF image) were so high. Does the reprojection procedure normally boost the file size so much higher, or are there only certain reprojections that cause this to happen. I have included the World Mercator 96 info that was used to provide us with the new projection (if that indeed will help any). Any assistance/suggestions would be appreciated. RSVP discussion group AND to this e-mail. Thanks, Brian ...LIne information from Mercator.dat..... proj_name mr96w, false_north 0, false_east 0, scale_factor 1, centre_merid -1.675516082, centre_lat 0, radius 6378206.4, eccentricity 0.082271854, flattening 294.9786982, prime_merid 1 ----------------------------------------------------------- To make changes to your subscription, please visit our website, http://www.ermapper.com/technicl/ermapperl/index.htm
