A wild question arrives in r/mathematica
Since this is r/mathematica, I can think of at least three ways -
In[]:=
ColorNegate
Out[]=
In[]:=
GraphicsColumnImageReflect
,ImageRotate
,Bottom,ImageReflect
,Left
Out[]=
In[]:=
ImageAdjust
-1
Out[]=
Hope this helps! Good luck with your project!