missing crop filter in gpuimage3

i was using gpuimage2 in my project.i want to migrate from gpuimage2 to gpuimage3 .
i was using crop() filter from gpuimage2 but in gpuimage3 i cant find it.
i am using this filter for obtaining different orientation like 1:1,3:4 and 9:16.
can anyone guide me how to obtain this functionality in gpuimage3?
thank you.