How to create image from array with millions of rows and 3 columns?

I am working on LiDAR data processing on MATLAB. I hav txt file with x,y,z data of 6 million rows and 3 columns. I need to convert it into image for further processing. How to do that? I imported the txt file to an array also. Help me.

Answer 1

[Chad Greene]

In your txt file, are the x and y values some regularly-spaced repeating pattern? By that I mean, does it look like:

x y 
1 1
1 2
1 3
2 1 
2 2
2 3
. .
. .
. .

or is your dataset a bunch of scattered points?

If the x,y values are already in some repeating pattern, you can likely reshape your z column to a gridded image.

If your x,y,z data are scattered I recommend John D'Errico's gridfit. Six million points will be no problem for gridfit as long as you don't try to map them to a high-resolution set of nodes. You'll have to tinker with the smoothing parameter a little bit. For my work with lidar data a smoothness value of 0.01 tends to be a good starting place.

[Image Analyst]

Or how about scatteredInterpolant()?