How can I export a matrix as a geotiff file?

I want load this matrix to ArcMap

I did several approach. I tried to convert .mat into ASCII (txt format) but it's not appear, maybe I did something wrong when I did the conversion.

Then I tried to save the file via a tool bar across the top of the figure, click on file, save as.

The result doesn't have correct coordinate system when I open on ArcMap.

Thank you for your help.

Intan

[Walter Roberson]

Is there a reason you have not used geotiffwrite() ?

[Intan Antasari]

I've tried beforehand but I got an error because I choose wrong example. I tried write an image referenced to geographic coordinate.I got some approach from this link https://nl.mathworks.com/help/map/exporting-images-and-raster-grids-to-geotiff.html

Which one should I choose for converting .mat data to projected coordinate system If I already have reference image beforehand?

Answer 1

[KSSV]

Let A be your matrix and (xmin,xmax) be your xlimits and (ymin,ymax) be your y limits.

% Get geo referenced 
R = georasterref('RasterSize',size(A),'LatitudeLimits',[ymin,ymax],'LongitudeLimits',[xmin,xmax]);
% write to tiff file 
tiffile = 'test.tif' ;
geotiffwrite(tiffile,A,R)
%% Read geotiff file
[A, R] = geotiffread(tiffile);

[Intan Antasari]

Is it should has parenthesie in line 4?

tiffile = ('test.tif');

I employed your code to my data. It works. I put the coordinate as same as reference map data. Then I got the result up side down.

Thank you

[KSSV]

Edited the typo error.....before writing to geotiff....you may try flipping your data matrix.

A = flipud(A) ;

Or may be you need to transpose....check with transpose also before writitng..looking at your attached image..I think transpose should work.

A = A' ;

[Intan Antasari]

I tried another options that I use the base data for retreving the coordinate.

% Load data
load ('lidar', 'map1')
load('LAS01.mat');
A = map1;
base = pc
xyz = pc(:,1:2);

% Get coordinate from base data
xmin = min(xyz(:,1));
xmax = max(xyz(:,1));
ymin = min(xyz(:,2));
ymax = max(xyz(:,2));

What should I use to export the data that have same coordinate with reference data?

Thank you for your help.

Intan

[Intan Antasari]

Flipping data give the right result than transpose. The figure is result from trasnpose data.

Thank you

Intan

[KSSV]

Perfect.....good.