yes, in the 1st tiff header the GeoTransform = 740551.2494, 0.078, 0.1506 189669.7013, 0.1506, -0.078
it means GeoTransform = <lon offset> <scale related> <nonzero rotation> <lat offset> <nonzero rotation> <scale related> if you transform the N-S oriented image in a NS oriented image I think the image will be magically displayed faster. Of course, adding tiled and overview with gdal should improve the performance. I think the problem isn't in the GDAL drivers because I try to open the same "slow" image with others OS GIS and the it's is displayed well. 2011/4/29 Patrice Vetsel <ubu...@kagou.fr> > Is it because the original is not Nort-South oriented and must be rotated > by QGis ? > > > Le 29/04/11 14:08, Patrice Vetsel a écrit : > > Hi, >> >> with an original raster (tif+tfw), from french cadastre, when I open it >> under qgis, it's unusable because QGis is horribly slow. >> with the same raster, but after using georef extension (tif+aux.xml), QGis >> is responsive >> >> here I put gdalinfo of the original (slow) and referenced : >> >> What's the problem with the first ? I would prefer to not have to manually >> georeference all my original rasters ;) >> >> In the same time, what's the most efficient raster type to use with QGis ? >> >> Regards >> >> >> Patrice Vetsel >> >> SLOW : >> MacBook-Pro-de-Patrice-Vetsel:~ Patrice$ >> /Library/Frameworks/GDAL.framework/Programs/gdalinfo >> ~/Desktop/3004221146000AB010200001.tif >> Driver: GTiff/GeoTIFF >> Files: /Users/Patrice/Desktop/3004221146000AB010200001.tif >> /Users/Patrice/Desktop/3004221146000AB010200001.tfw >> Size is 12329, 8760 >> Coordinate System is `' >> GeoTransform = >> 740551.2494, 0.078, 0.1506 >> 189669.7013, 0.1506, -0.078 >> Metadata: >> TIFFTAG_ARTIST=JBG-PYV-APIC >> TIFFTAG_XRESOLUTION=300 >> TIFFTAG_YRESOLUTION=300 >> TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch) >> Image Structure Metadata: >> COMPRESSION=CCITTFAX4 >> INTERLEAVE=BAND >> MINISWHITE=YES >> Corner Coordinates: >> Upper Left ( 740551.249, 189669.701) >> Lower Left ( 741870.505, 188986.421) >> Upper Right ( 741512.911, 191526.449) >> Lower Right ( 742832.167, 190843.169) >> Center ( 741691.708, 190256.435) >> Band 1 Block=12329x1 Type=Byte, ColorInterp=Palette >> Image Structure Metadata: >> NBITS=1 >> Color Table (RGB with 2 entries) >> 0: 255,255,255,255 >> 1: 0,0,0,255 >> >> >> OK : >> MacBook-Pro-de-Patrice-Vetsel:~ Patrice$ >> /Library/Frameworks/GDAL.framework/Programs/gdalinfo >> ~/Desktop/testgeo/AB_georef.tif >> Driver: GTiff/GeoTIFF >> Files: /Users/Patrice/Desktop/testgeo/AB_georef.tif >> /Users/Patrice/Desktop/testgeo/AB_georef.tif.aux.xml >> Size is 13446, 14968 >> Coordinate System is `' >> Origin = (740550.783870017039590,191526.220101331215119) >> Pixel Size = (0.169699598291267,-0.169699598291267) >> Image Structure Metadata: >> INTERLEAVE=BAND >> Corner Coordinates: >> Upper Left ( 740550.784, 191526.220) >> Lower Left ( 740550.784, 188986.157) >> Upper Right ( 742832.565, 191526.220) >> Lower Right ( 742832.565, 188986.157) >> Center ( 741691.674, 190256.188) >> Band 1 Block=13446x1 Type=Byte, ColorInterp=Palette >> Color Table (RGB with 256 entries) >> 0: 255,255,255,255 >> 1: 0,0,0,255 >> 2: 0,0,0,255 >> 3: 0,0,0,255 >> 4: 0,0,0,255 >> 5: 0,0,0,255 >> 6: 0,0,0,255 >> 7: 0,0,0,255 >> 8: 0,0,0,255 >> 9: 0,0,0,255 >> 10: 0,0,0,255 >> 11: 0,0,0,255 >> 12: 0,0,0,255 >> 13: 0,0,0,255 >> 14: 0,0,0,255 >> 15: 0,0,0,255 >> 16: 0,0,0,255 >> 17: 0,0,0,255 >> 18: 0,0,0,255 >> 19: 0,0,0,255 >> 20: 0,0,0,255 >> 21: 0,0,0,255 >> 22: 0,0,0,255 >> 23: 0,0,0,255 >> 24: 0,0,0,255 >> 25: 0,0,0,255 >> 26: 0,0,0,255 >> 27: 0,0,0,255 >> 28: 0,0,0,255 >> 29: 0,0,0,255 >> 30: 0,0,0,255 >> 31: 0,0,0,255 >> 32: 0,0,0,255 >> 33: 0,0,0,255 >> 34: 0,0,0,255 >> 35: 0,0,0,255 >> 36: 0,0,0,255 >> 37: 0,0,0,255 >> 38: 0,0,0,255 >> 39: 0,0,0,255 >> 40: 0,0,0,255 >> 41: 0,0,0,255 >> 42: 0,0,0,255 >> 43: 0,0,0,255 >> 44: 0,0,0,255 >> 45: 0,0,0,255 >> 46: 0,0,0,255 >> 47: 0,0,0,255 >> 48: 0,0,0,255 >> 49: 0,0,0,255 >> 50: 0,0,0,255 >> 51: 0,0,0,255 >> 52: 0,0,0,255 >> 53: 0,0,0,255 >> 54: 0,0,0,255 >> 55: 0,0,0,255 >> 56: 0,0,0,255 >> 57: 0,0,0,255 >> 58: 0,0,0,255 >> 59: 0,0,0,255 >> 60: 0,0,0,255 >> 61: 0,0,0,255 >> 62: 0,0,0,255 >> 63: 0,0,0,255 >> 64: 0,0,0,255 >> 65: 0,0,0,255 >> 66: 0,0,0,255 >> 67: 0,0,0,255 >> 68: 0,0,0,255 >> 69: 0,0,0,255 >> 70: 0,0,0,255 >> 71: 0,0,0,255 >> 72: 0,0,0,255 >> 73: 0,0,0,255 >> 74: 0,0,0,255 >> 75: 0,0,0,255 >> 76: 0,0,0,255 >> 77: 0,0,0,255 >> 78: 0,0,0,255 >> 79: 0,0,0,255 >> 80: 0,0,0,255 >> 81: 0,0,0,255 >> 82: 0,0,0,255 >> 83: 0,0,0,255 >> 84: 0,0,0,255 >> 85: 0,0,0,255 >> 86: 0,0,0,255 >> 87: 0,0,0,255 >> 88: 0,0,0,255 >> 89: 0,0,0,255 >> 90: 0,0,0,255 >> 91: 0,0,0,255 >> 92: 0,0,0,255 >> 93: 0,0,0,255 >> 94: 0,0,0,255 >> 95: 0,0,0,255 >> 96: 0,0,0,255 >> 97: 0,0,0,255 >> 98: 0,0,0,255 >> 99: 0,0,0,255 >> 100: 0,0,0,255 >> 101: 0,0,0,255 >> 102: 0,0,0,255 >> 103: 0,0,0,255 >> 104: 0,0,0,255 >> 105: 0,0,0,255 >> 106: 0,0,0,255 >> 107: 0,0,0,255 >> 108: 0,0,0,255 >> 109: 0,0,0,255 >> 110: 0,0,0,255 >> 111: 0,0,0,255 >> 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>> 223: 0,0,0,255 >> 224: 0,0,0,255 >> 225: 0,0,0,255 >> 226: 0,0,0,255 >> 227: 0,0,0,255 >> 228: 0,0,0,255 >> 229: 0,0,0,255 >> 230: 0,0,0,255 >> 231: 0,0,0,255 >> 232: 0,0,0,255 >> 233: 0,0,0,255 >> 234: 0,0,0,255 >> 235: 0,0,0,255 >> 236: 0,0,0,255 >> 237: 0,0,0,255 >> 238: 0,0,0,255 >> 239: 0,0,0,255 >> 240: 0,0,0,255 >> 241: 0,0,0,255 >> 242: 0,0,0,255 >> 243: 0,0,0,255 >> 244: 0,0,0,255 >> 245: 0,0,0,255 >> 246: 0,0,0,255 >> 247: 0,0,0,255 >> 248: 0,0,0,255 >> 249: 0,0,0,255 >> 250: 0,0,0,255 >> 251: 0,0,0,255 >> 252: 0,0,0,255 >> 253: 0,0,0,255 >> 254: 0,0,0,255 >> 255: 0,0,0,255 >> >> >> _______________________________________________ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/qgis-user >> > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/qgis-user >
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