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Binary_template + read_binary [message #53891]

Wed, 09 May 2007 09:00

rats06
Messages: 3
Registered: May 2007

Junior Member

Hi,

I have a LiDAR file in LAS FORMAT. I am trying to read this file using
BINARY_TEMPLATE and READ_BINARY but I am having some problems.
The only way I am being able to extract correctly all the information
is if I loop many times as the number of points I have in the dataset
and every time incrementing the TEMPLATE.OFFSET by 28 bytes.

What I mean is:

The format of the binary file should be:
Field1 = 4 bytes
Field2 = 4 bytes
Field3 = 4 bytes
Field4 = 2 bytes
Field5 = 1 byte
Field6 = 1 byte
Field7 = 1 byte
Field8 = 1 byte
Field9 = 2 bytes
Field10 = 8 bytes
Total number of bytes = 28

NUM_POINT_RECORDS = 276848 points

So, I create a TEMPLATE with BINARY_TEMPLATE with 10 fields using the
format above but using the NUMBER OF DIMENSIONS as a SCALAR.
Doing that and using the code:

for i = 0, NUM_POINT_RECORDS -1 do begin
data = read_binary(FILENAME, template=template)
template.offset[0] = template.offset[0] + 28
printf, ...
endfor

It works like that ... but of course too slow ... I tried putting the
NUMBER OF DIMENSIONS to 1 and using the NUM_POINT_RECORDS (276848
points) as the value ... but it doesn't work ... the result is not
the same as when I loop ...

How can I do that without looping ?

Thank you

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[Message index]

		Binary_template + read_binary By: rats06 on Wed, 09 May 2007 09:00
		Re: Binary_template + read_binary By: rats06 on Wed, 09 May 2007 11:13
		Re: Binary_template + read_binary By: rats06 on Wed, 09 May 2007 11:12
		Re: Binary_template + read_binary By: Paul Van Delst[1] on Wed, 09 May 2007 09:15

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