Greetings, fellow mappers: We're having some problems geo-referencing an image, and though perhaps there might be some advice from the group. We're on the NW USA coast, and make good use of raster nautical charts. The charts are in a compressed, proprietary .KAP format, which fortunately is readable in MapInfo with the help of WorldReg Plus, a utility available from Tony Cooley (email: [EMAIL PROTECTED], URL: http://members.aol.com/mapdata/). Some of the small scale charts have a wonderful hand-drawn quality about them, that with a bit of editing would make a wonderful region map. However, no paint program can read the .KAP format. My solution was to bring the geo-referenced nautical image up in MapInfo, zoom out to what I wanted to use as my locator map (the Puget Sound region, rather than the entire northwest coast) then FILE/SAVE WINDOW AS ... and saving it at triple the given resolution, as a .BMP file. That result was a good quality bitmap image that I could pixel-edit in MS Paint. I got rid of lines and text I didn't want, generally cleaning up the image. I then saved it. In MapInfo, I had the original chart open, and chose points on the chart near the corners of the area I had saved as the bitmap. Under MAP/OPTIONS/DISPLAY IN STATUS BAR I chose "cursor location." I carefully zoomed in on the chart and noted the exact Lat Lon reading for the points I had chosen. Next I opened the cleaned up bitmap image in MapInfo to geo-register it. I chose the appropriate projection (Lon-Lat WGS84) as defined in the written text of the chart and confirmed in MapInfo using Tony Cooley's LOCATE utility. I chose the same points I had chosen in the intact chart, and made those my control points. Everything's in Lon Lat WGS84, the exact same points are chosen as control points - yet the control points are up to 600 pixels in error according to the geo-reference window. The new bitmap displays perfectly. But when I try to overlay existing vector data atop it, it is VERY messed up. In fact, vector layers tend to display as a diagonal slice of black along the center of the image. Yikes! What did I do wrong? Any suggestions would be welcome! Tom * - * - * - * - * Tom Curley Suquamish Tribe GIS Program Manager [EMAIL PROTECTED] ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
