[gdal-dev] Converting from Lambert (LCC) to latlong/mercator
idlegod at gmail.com
Sat Feb 21 23:07:49 EST 2009
>From the gdal_translate line, the images are identical, but with added
information to the tif, in a geotif style.
Once I warp it, the image is squished (as I would expect), but the
width is the same.
I have also tried embedding all of the geotiff data within the
intermediate image, but for some reason, I just cannot seem to set the
pixel size. If I create a wld or a tfw file, it just seems to ignore
gdal_translate -of gtiff -CO TFW=YES -a_ullr -115 56 -105 54 -a_srs
"+proj=lcc +lat_0=56 +lon_0=-115 +lat_2=49.33 +lat_1=54.66 +x_0=0
+y_0=0 +datum=NAD27" n.tif nn.tif
I am wondering if perhaps its because photoshop added a bunch of
incorrect meta data:
TIFFTAG_SOFTWARE=Adobe Photoshop CS3 Macintosh
To my eyes, that looks like 72pixels per inch, which is about right
for the scanner it came in from, but wrong for the actual map scale. I
cannot find a way in photoshop to change that, and it definitely
doesn't like scaling to sizes below 1.0
On Sat, Feb 21, 2009 at 8:45 PM, Wendy Fay Stevenson <stevensw at erau.edu> wrote:
> Have you not got a world file for your image?
> I would agree that the pixel size does not seem right. I
> would try writing my own world file with reasonable values -
> just to see if the image come out looking better. Make sure
> you call it the same name as your original tiff file (with
> .wld or .twf extention) and gdal will automatically pick it
> What results do you get if you run gdalinfo on the new file?
> Does it have more or less the same number of pixels?
> I know you can set the resolution with gdalwarp but I haven't
> tried that.
> About the false eastings and northings, it would very much
> depend on the projection of the original image. If they do
> not specify I would assume they are 0.
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