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Re: Conversion floating point to byte or integer [message #56296 is a reply to message #56292]

Thu, 11 October 2007 14:04

M. Katz
Messages: 69
Registered: May 2005

Member

You have to guard against byte values going below zero.
Here is what I would recommend.
1) Immediately convert the raw data into float, before any processing.
2) Subtract the background array but "crop" any negative values at
zero.
image1 = (raw_data - background ) > 0.
3) Then apply your calibration
image2 = image1 * calibration
If instead you have to divide by the calibration array, watch out
for zeros.
image2 = image1 / (calibration > 1.) might be a format you should
consider.
(The 1. here is just an example. It depends on your actual data.)

Of course be careful about spikes or zeros in the calibration
file or background file. Those can cause problems.

MKatz

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[Message index]

		Re: Conversion floating point to byte or integer By: beardown911 on Thu, 11 October 2007 18:44
		Re: Conversion floating point to byte or integer By: M. Katz on Thu, 11 October 2007 14:04
		Re: Conversion floating point to byte or integer By: beardown911 on Thu, 11 October 2007 06:22
		Re: Conversion floating point to byte or integer By: beardown911 on Thu, 11 October 2007 06:20
		Re: Conversion floating point to byte or integer By: Maarten[1] on Thu, 11 October 2007 01:05
		Re: Conversion floating point to byte or integer By: Jean H. on Wed, 10 October 2007 23:08
		Re: Conversion floating point to byte or integer By: beardown911 on Wed, 10 October 2007 21:20
		Re: Conversion floating point to byte or integer By: Jean H. on Wed, 10 October 2007 16:44

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