Two Dimensional Discrete Fast Wavelet Transform
[CA,CH,CV,CD]=dwt2(x,wname,['mode',extMethod]) [CA,CH,CV,CD]=dwt2(x,Lo_D,Hi_D,['mode',extMethod])
dwt2 is for two dimension discrete fast wavelet transform with the signal extension method optional argument.
x=rand(100,100); [CA,CH,CV,CD]=dwt2(x,'db2','mode','asymh');
Roger Liu and Isaac Zhi