I need to georreference a .tif file containing a single band image with pixel depth 16 bits (unsigned). The number of columns and rows is 946 and 843, respectively. The boundaries of the image are (lat long):
Upper Left: (-26.3715412589932 -66.5047101346368)
Upper Right: (-26.35416349341 -65.6533514552353)
Lower Left: (-27.0551004785532 -66.4897545206575)
Lower Right: (-27.0372010091334 -65.6333136358799)
I tried a code that doesn't worth mention here because it yielded really bad results.
The question is if there is one piece of code to end up with a georreferenced .tif image that my gis will read automatically.
Thanks in advance.
Thanks for your help link, but i was looking for something more like a piece of code or script; i already read the explanation for geotiffwrite, but i cannot fully understand it in order to use it.
[I, path]=uigetfile('*.tif','*.tiff','Select Image');
cd(path)
[A, R] = geotiffread(I);
info = geotiffinfo(I)
%R.RasterSize = size(I)
geotiffwrite('rout.tif', B , R, 'GeoKeyDirectoryTag', info.GeoTIFFTags.GeoKeyDirectoryTag) % B is output variable
Thank you for your answer Sama, can you comment more extensively your script? I found one that solves the original problem partially, because now i have to deal with geolocation errors.
% UTM coordinates of boundaries of hte image
lonmin = ;
lonmax = ;
latmin = ;
latmax = ;
%
% Size of the pixel (DY and DX are positive or negative depending on the latitude or longitude increasing or decreasing; if latitude decreases from row to row like in the case of negative latitudes, DY must be negative)
DX = ;
DY = ;
%
% Generating world file for the image matrix. Image name has ".tfw" extension if image is a ".tif" file. If it has a different extension then in most cases first and third character of the extension plus "w" letter will work (e.g. ".jpw").
R = makerefmat(lonmin, latmin, DX, DY);
worldfilewrite(R,'');
%
% Reading worldfile, creating geotiff. EPSG code should be replaced for the right one.
REF = worldfileread('','planar',size());
geotiffwrite('',,REF,'CoordRefSysCode', 'EPSG: 32719');
Now the image is located in place and well oriented, but it has considerable geolocation errors (~1,5 km deviations east), so i will have to try something different. I'm not sure if deviations respond to the method used for constructing the image or to the boundary coordinates choosing (i read them from the metadata of the file, but i don't know if the boundary coordinates are the same for all ASTER bands).
Hi Matias Lestussi ,
Go through this link .....
https://www.mathworks.com/help/map/universal-transverse-mercator-system.html?s_tid=CRUX_lftnav
The selection of the UTM Zone it's a little bit complicated because the area lies just in the limit of two zones. I chose the one selected for imagery from another sensors that i got already georeferenced 19S. The ellipsoid is WGS84. I'm trying another script at the moment, based on fitgeotrans function, i will comment my results later
I managed to get the georeferenced tiff image with the script that i shared, the deviations i got were because of a constant displacement in the scene boundaries of TIR images with respect to vnir ones. I substracted 1500 meters from lon min and lon max and now the image (ASTER TIR Image) aligns perfectly with Landsat 7 and Sentinel 2A images.
Hi Matias,
I am trying to use your script to convert a tif into a georefference file to be read in ArcMAp. However, I get stuck in line 12 R = makerefmat(lonmin, latmin, DX, DY); and matlab reports an error here. Any ideas? Thanks a lot in advance.
Emilia
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