[Gdal-dev] TFW / WLD file error

[Carl Anderson]

I have blundered into an error handling WLD files in Lat/Long usages

For the following examples I tried tif + tfw, pnm + wld, jpg + wld, jpg 
+ jpw image and georeferencing  files.
I even tried passing it through gdal_translate.

first example produces invalid info

if the WLD file is
2.014
0
0
-2.014
-85.34
34.53

gdalinfo my.tif
Driver: GTiff/GeoTIFF
Size is 395, 511
Coordinate System is `'
Origin = (-86.347000,35.537000)
Pixel Size = (2.01400000,-2.01400000)
Corner Coordinates:
Upper Left  ( -86.3470000,  35.5370000)
Lower Left  (     -86.347,    -993.617)
Upper Right (     709.183,      35.537)
Lower Right (     709.183,    -993.617)
Center      (     311.418,    -479.040)
Band 1 Block=395x20 Type=Byte, ColorInterp=Red
Band 2 Block=395x20 Type=Byte, ColorInterp=Green
Band 3 Block=395x20 Type=Byte, ColorInterp=Blue


if I add arbitray digits to the WLD file by simply editnig that file
2.014
0
0
-2.014
-555585.34
555534.53

gdalinfo my.tif
Driver: GTiff/GeoTIFF
Size is 395, 511
Coordinate System is `'
Origin = (-555586.347000,555535.537000)
Pixel Size = (2.01400000,-2.01400000)
Corner Coordinates:
Upper Left  ( -555586.347,  555535.537)
Lower Left  ( -555586.347,  554506.383)
Upper Right ( -554790.817,  555535.537)
Lower Right ( -554790.817,  554506.383)
Center      ( -555188.582,  555020.960)
Band 1 Block=395x16 Type=Byte, ColorInterp=Red
Band 2 Block=395x16 Type=Byte, ColorInterp=Green
Band 3 Block=395x16 Type=Byte, ColorInterp=Blue

C.