http://imagej.273.s1.nabble.com/Image-Rotations-and-ip-setBackgroundValue-tp5021339p5021341.html
> Hi Herbie,
>
> yes, the "Fill with Background Color" checkbox is disabled for 16-bit
> and float images in Image>Transform>Rotate (ij.plugin.Rotator.java)
>
> One could easily remove that limitation, but one would also have to
> modify the code for rotate() and scale() in ShortProcessor and
> FloatProcessor (currently it uses zero filling) and write the code for
> get/setBackgroundValue methods. So I fear it is more than a few minutes.
>
> For me, the nicest would be a 'select rotated' option for the 'Rotate'
> command; then I could invert the selection thereafter and maybe even
> create a background with smooth borders to avoid artifacts in FFT - but
> I fear that it is difficult to get the selection rectangle correct
> (without rounding errors, which might leave zero pixels).
>
> For the moment, the easiest might be converting to float, subtracting
> the background value you prefer, then rotating and adding the background
> value.
>
> Michael
> ________________________________________________________________
> On 24/10/18 17:44, Herbie wrote:
>> Dear experts,
>>
>> my question concerns ways to fill *only* the corner areas that result
>> from
>> rotated images and that work with 8bit, 16bit and 32bit images.
>>
>> I should like to fill these areas with the mode value of the images.
>>
>> "ip.setBackgroundValue()"
>>
>> appears to work with 8bit images only.
>>
>> Is there a reliable way to do this with 16bit and 32bit images?
>>
>> (What I did already is select the zero-valued corner areas with the
>> Wand-tool and then fill them, but if the image structure is zero as
>> well and
>> touches a corner area, it becomes filled as well...)
>>
>> (Another approach not, tested yet, is to rotate a rectangular
>> selection as
>> well and fill outside.)
>>
>> Any suggestions are welcome
>>
>> Herbie
>>
>
> --
> ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>