Preserving pixel values in saved image

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Preserving pixel values in saved image

Martin Kavec-2
Hi,

I have the following problem:

I open a raw image (16-bit unsigned) do some treatment (no change to pixel
values though) on it and than I save it again as raw. If I again
open the image as raw, the pixel values are rescaled, different from the
original. Some of them even flow over the 16-bit value limit. Even worse, the
scaling is different if I adjust brightness/contrast. I have un-checked
option to Scale image, when converting, but the result is the same.
Preservation of the pixel values is critical for what I do.

I run ImageJ 1.36b on MacBook Pro. Thanks for advice in advance.

Martin
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Re: Preserving pixel values in saved image

Wayne Rasband
 > I open a raw image (16-bit unsigned) do some treatment (no
 > change to pixel values though) on it and than I save it
 > again as raw. If I again open the image as raw, the pixel
 > values are rescaled, different from the original. Some of
 > them even flow over the 16-bit value limit. Even worse, the
 > scaling is different if I adjust brightness/contrast. I have
 > un-checked option to Scale image, when converting, but the
 > result is the same. Preservation of the pixel values is
 > critical for what I do.

 >I run ImageJ 1.36b on MacBook Pro. Thanks for advice in advance.

16 and 32 bit images saved using File>Save As>Raw Data are in
big-endian byte order unless "Export Raw in Intel Byte Order" is
checked in the Edit>Options>Input/Output dialog box. This option was
added in ImageJ 1.37e.

-wayne