[gdal-dev] add tranperency

[Jan Tappenbeck]

  Hi !

i have a image with following data:

C:\Program Files (x86)\FWTools2.4.7>gdalinfo "[Path]\trans_a.tif"
Driver: GTiff/GeoTIFF
Files: D:\brumi\VG_Bruchmuehlbach-Miesau_DOP\geotiff\trans_a.tif
Size is 10390, 10390
Coordinate System is:
PROJCS["DHDN / 3-degree Gauss-Kruger zone 2",
     GEOGCS["DHDN",
         DATUM["Deutsches_Hauptdreiecksnetz",
             SPHEROID["Bessel 1841",6377397.155,299.1528128000009,
                 AUTHORITY["EPSG","7004"]],
             AUTHORITY["EPSG","6314"]],
         PRIMEM["Greenwich",0],
         UNIT["degree",0.0174532925199433],
         AUTHORITY["EPSG","4314"]],
     PROJECTION["Transverse_Mercator"],
     PARAMETER["latitude_of_origin",0],
     PARAMETER["central_meridian",6],
     PARAMETER["scale_factor",1],
     PARAMETER["false_easting",2500000],
     PARAMETER["false_northing",0],
     UNIT["metre",1,
         AUTHORITY["EPSG","9001"]],
     AUTHORITY["EPSG","31466"]]
Origin = (2601576.178792405400000,5477422.986974134100000)
Pixel Size = (0.200049845331526,-0.200049845331526)
Metadata:
   AREA_OR_POINT=Area
Image Structure Metadata:
   INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  ( 2601576.179, 5477422.987) (  7d24'1.33"E, 49d25'34.75"N)
Lower Left  ( 2601576.179, 5475344.469) (  7d23'59.41"E, 49d24'27.48"N)
Upper Right ( 2603654.697, 5477422.987) (  7d25'44.45"E, 49d25'33.49"N)
Lower Right ( 2603654.697, 5475344.469) (  7d25'42.50"E, 49d24'26.22"N)
Center      ( 2602615.438, 5476383.728) (  7d24'51.92"E, 49d25'0.49"N)
Band 1 Block=10390x1 Type=Byte, ColorInterp=Red
Band 2 Block=10390x1 Type=Byte, ColorInterp=Green
Band 3 Block=10390x1 Type=Byte, ColorInterp=Blue

there are black arrows at the border (by transformation) - is it 
possible to make i transparency ?

how?

gdal_translate -of ECW old_image.tif new_image.ecw

tells that is unpossible !!!

can you help me ?

regards Jan :-)