MATLAB: Roipoly help – colours display badly (so unable to define)

colourmaskroiroipoly

I have a 1660 x 986 matrix with values up to 2500 (it represents a digital elevation model).
I need to define an area using roipoly but when it displays in roipoly, the colour bar only goes up to 1, so the whole image is white apart from one small spot near 0.
In case this is relevant, it does tell me:
Warning: Image is too big to fit on screen; displaying at 33% > In imuitools/private/initSize at 73 In imshow at 262 In roipoly>parse_inputs at 191 In roipoly at 81
Is there a way to solve this?! Thank you

Best Answer

What is class() of the data? With that range of values, if it is not int16 or uint16 then it is not an "image" as is required for input to roipoly()
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