I am trying to stitch together several satellite geotiff images to obtain a world image.<br>The individual images display the satellite picture with black areas on the sides of the picture itself.<br>So, when merging the images using gdal_merge.py some pictures are hidden underneath the black portion of neighbour images. Couldn't use -pct option due to images characteristics. Pls. see below the color tables in the input images.
<br><br>The original images do not have a no-data value assigned to pixels to avoid copying them. <br>So, for now my only option would be to crop the black areas that are always the same size around the image. I am trying to do this using gdalwarp, but I still can't figure out how to obtain the georeferenced box to be used along with -projwin option.
<br><br>BTW. I haven't been able to see these images using OpenEV although I can see them with ImageMagick. Any idea on what I may be doing wrong in OpenEV? I do need to run openev with the "-h" option since it quits on me when opening an image otherwise. I have been able to see other geotiffs downloaded from Internet in openev though.
<br><br>Any help on how to cut the black areas is appreciated.<br><br><br><br>Some info on 2 of the input images and the output images:<br><br>Input number 1<br><br>Origin = (45.833333,75.000000)<br>Pixel Size = (0.08055556
,-0.08055556)<br>Metadata:<br> AREA_OR_POINT=Area<br>Corner Coordinates:<br>Upper Left ( 45.8333333, 75.0000000) (142d30'0.03"E, 0d 0'0.04"N)<br>Lower Left ( 45.8333333, -70.0000000) (142d30'0.03"E, 0d 0'
0.04"S)<br>Upper Right ( 239.167, 75.000) (142d30'0.14"E, 0d 0'0.04"N)<br>Lower Right ( 239.167, -70.000) (142d30'0.14"E, 0d 0'0.04"S)<br>Center ( 142.5000000, 2.5000000) (142d30'
0.08"E, 0d 0'0.00"N)<br>Band 1 Block=2400x3 Type=Byte, ColorInterp=Palette<br> Color Table (RGB with 256 entries)<br> 0: 0,0,0,255<br> 1: 0,0,0,255<br> 2: 0,0,0,255<br> 3: 0,0,0,255<br> 4: 0,0,0,255
<br> 5: 0,0,0,255<br> 6: 0,0,0,255<br> 7: 0,0,0,255<br> 8: 0,0,0,255<br> 9: 0,0,0,255<br> 10: 0,0,0,255<br> 11: 0,0,0,255<br> 12: 0,0,0,255<br> 13: 0,0,0,255<br> 14: 0,0,0,255<br> 15: 0,0,0,255<br>
16: 0,0,0,255<br> 17: 0,0,0,255<br> 18: 0,0,0,255<br> 19: 0,0,0,255<br> 20: 0,0,0,255<br>...............................................................rest of values in color table look the same<br><br>Input number 2
<br>Driver: GTiff/GeoTIFF<br>Size is 2400, 1800<br>Coordinate System is:<br>PROJCS["unnamed",<br> GEOGCS["unnamed",<br> DATUM["WGS_1984",<br> SPHEROID["WGS 84",6378137,
298.2572235629972,<br> AUTHORITY["EPSG","7030"]],<br> AUTHORITY["EPSG","6326"]],<br> PRIMEM["Greenwich",0],<br> UNIT[,0.0174532925199433
]],<br> PROJECTION["Equirectangular"],<br> PARAMETER["latitude_of_origin",2.5],<br> PARAMETER["central_meridian",-155],<br> PARAMETER["false_easting",0],<br> PARAMETER["false_northing",0],
<br> UNIT["degree",0.01745329251994328,<br> AUTHORITY["EPSG","9102"]]]<br>Origin = (-251.537842,74.963768)<br>Pixel Size = (0.08051530,-0.08051530)<br>Metadata:<br> AREA_OR_POINT=Area
<br>Corner Coordinates:<br>Upper Left ( -251.538, 74.964) (155d 0'0.14"W, 0d 0'0.04"N)<br>Lower Left ( -251.538, -69.964) (155d 0'0.14"W, 0d 0'0.04"S)<br>Upper Right ( -58.3011272,
74.9637681) (155d 0'0.03"W, 0d 0'0.04"N)<br>Lower Right ( -58.3011272, -69.9637681) (155d 0'0.03"W, 0d 0'0.04"S)<br>Center (-154.9194847, 2.5000000) (155d 0'0.09"W, 0d 0'0.00"N)<br>
Band 1 Block=2400x3 Type=Byte, ColorInterp=Palette<br> Color Table (RGB with 256 entries)<br> 0: 0,0,0,255<br> 1: 0,0,0,255<br> 2: 0,0,0,255<br> 3: 0,0,0,255<br> 4: 0,0,0,255<br> 5: 0,0,0,255<br> 6: 0,0,0,255
<br> 7: 0,0,0,255<br> 8: 0,0,0,255<br> 9: 0,0,0,255<br> 10: 0,0,0,255<br> 11: 0,0,0,255<br> 12: 0,0,0,255<br> 13: 0,0,0,255<br> 14: 0,0,0,255<br> 15: 0,0,0,255<br> 16: 0,0,0,255<br> 17: 0,0,0,255<br>
18: 0,0,0,255<br> 19: 0,0,0,255<br> 20: 0,0,0,255<br>.................................................................. rest of values in color table look the same<br><br><br>Output from gdal_merge.py -o <outpiut> <Input number 1> <Input number 2>
<br>Driver: GTiff/GeoTIFF<br>Size is 6067, 1800<br>Coordinate System is:<br>PROJCS["unnamed",<br> GEOGCS["WGS 84",<br> DATUM["WGS_1984",<br> SPHEROID["WGS 84",6378137,
298.2572235629972,<br> AUTHORITY["EPSG","7030"]],<br> AUTHORITY["EPSG","6326"]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",
0.0174532925199433],<br> AUTHORITY["EPSG","4326"]],<br> PROJECTION["Equirectangular"],<br> PARAMETER["latitude_of_origin",0],<br> PARAMETER["central_meridian",135],
<br> PARAMETER["false_easting",0],<br> PARAMETER["false_northing",0],<br> UNIT["unknown",1]]<br>Origin = (-243.264249,69.948187)<br>Pixel Size = (0.07772021,-0.07772021)<br>Metadata:
<br> AREA_OR_POINT=Area<br>Corner Coordinates:<br>Upper Left ( -243.264, 69.948) (134d59'52.13"E, 0d 0'2.28"N)<br>Lower Left ( -243.264, -69.948) (134d59'52.13"E, 0d 0'2.28"S)<br>Upper Right (
228.264, 69.948) (135d 0'7.38"E, 0d 0'2.28"N)<br>Lower Right ( 228.264, -69.948) (135d 0'7.38"E, 0d 0'2.28"S)<br>Center ( -7.5000000, -0.0000000) (134d59'59.76"E, 0d 0'0.00"S)
<br>Band 1 Block=6067x1 Type=Byte, ColorInterp=Gray<br><br><br><br>