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Re: Conversion floating point to byte or integer [message #56325 is a reply to message #56322]

Wed, 10 October 2007 16:44

Jean H.
Messages: 472
Registered: July 2006

Senior Member

go cats wrote:
> Hello Gurus,
>
> I've been trying to write a code to correct imagery data. Original
> imagery data format is byte format.
> Steps for the processing includes reading the original data,
> subtracting dark current, and multiplying calibration coefficients and
> saving the results. The two values; dark current and calibration
> coefficients are given by arrays with floationg point format.
> The code seemes to work without any problem. But in the resulting
> image saved in binary format , numbers higher than 255 store only
> remants of what is subtracted from 256. The reason I want to convert
> to byte is to save some disk space. In the image saved as floating
> point format pixel values look ok.
> Could you give some advice what part of program I have to look at? and
> what causes this problem?
>
> Thank you in advance,
> Kim

So what do you want to do with values greater than 255?

You could do
1) compute your new image as a float,
2) scale everything down so ALL of your values are between 0 and 255 and
save the image
or 2) brightPixels = where(image gt 255)
image[brightPixels] = 255 and save the image

Jean

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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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