Changes not saved in tiff image

[Malgosia]

Hello,

I am trying to save some changes I made to a 16-bit tiff file in Image J.  I open the file, modify the brightness/contrast and then re-save as a tiff.  But the new tiff image does not have the changes I made.  It works when I save as jpeg, but I don't want to lose the image data.

Anyone have a solution to this problem?

Thanks!

Malgosia

[Emanuele Martini]

Hi,
it is because adjust brightness and contrast doesn't work with 16 bit images (if you look at help or in the toolbar it says that to you...)
Even if i never understood why...
Have a nice day,
Emanuele Martini

[Michael Schmid]

Hi Malgosia,

the Brightness/Contrast settings don't modify the image contents, just the way how the image is displayed. For 8-bit and RGB images, you can click "Apply" in the B&C panel to make the change permanent.

There is no such option for 16-bit or floating-point (32-bit) images. If you need the image for display purposes only (not for further analysis), you can adjust B&C and then convert it to 8 bits (make sure that "scale when converting" is on in Edit>Options>Conversions), then save it as 8-bit image (PNG or whatever format you like).

If you want to keep the 16-bit data inside the display range, but truncate everything outside, you can use Process>Math>Min and Max to set all pixels outside the Min...Max range to the limits. If you have the 16-bit range set to "Automatic" in Edit>Options>Appearance, the image will be opened with that range. Of course, this modifies the image data.

Hope this helps,

Michael
________________________________________________________________
On May 8, 2015, at 06:35, Malgosia wrote:

> Hello,
>
> I am trying to save some changes I made to a 16-bit tiff file in Image J.  I
> open the file, modify the brightness/contrast and then re-save as a tiff.
> But the new tiff image does not have the changes I made.  It works when I
> save as jpeg, but I don't want to lose the image data.
>
> Anyone have a solution to this problem?
>
> Thanks!
>
> Malgosia
>
>
>
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> Sent from the ImageJ mailing list archive at Nabble.com.
>
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> ImageJ mailing list: http://imagej.nih.gov/ij/list.html

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[Malgosia]

Thanks Michael that was really helpful.  Now it saves the changes, but still not the way I see them in before I save.  I reset the min value and the image looked correct (all the pixels below that min were black) but when I saved it made the background of the image dark grey instead of black....

[Rasband, Wayne (NIH/NIMH) [E]]

> On May 8, 2015, at 12:35 AM, Malgosia <[hidden email]> wrote:
>
> Hello,
>
> I am trying to save some changes I made to a 16-bit tiff file in Image J.  I
> open the file, modify the brightness/contrast and then re-save as a tiff.
> But the new tiff image does not have the changes I made.  It works when I
> save as jpeg, but I don't want to lose the image data.
>
> Anyone have a solution to this problem?

You need to make the lookup table changes permanent by clicking on “Apply” in the “B&C” dialog. You will also need to upgrade to the latest ImageJ daily build (1.49t11). The “Apply” button did not work with 16-bit images in earlier versions of ImageJ. To upgrade, use the Help>Update ImageJ command and select “daily build” from the drop down menu.

-wayne

> --
> View this message in context: http://imagej.1557.x6.nabble.com/Changes-not-saved-in-tiff-image-tp5012767.html
> Sent from the ImageJ mailing list archive at Nabble.com.



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