a=60;
b=150;
c=10;
d =70;
(*a=180;
b=250;
c=70;
d =220;
*)A= ImageData[ColorConvert[ 
Import["/Users/felix/fie_mac/Investigacion/BilateralFilter/Lena_origen_5.png"], "Grayscale"]
];
A0 =A; A[[a;;b,c;;d]];
A1= ImageData[ColorConvert[
Import["/Users/felix/fie_mac/Investigacion/BilateralFilter/Lena_BF_25.png"], "Grayscale"]];
A2 =A1;A1[[a;;b,c;;d]];
A3= ImageData[ColorConvert[Import["/Users/felix/fie_mac/Investigacion/BilateralFilter/Lena_TF_25.png"], "Grayscale"]];
A4 = A3; A3[[a;;b,c;;d]];
{Image[A0], LaplacianFilter[Image[A0],1]//ImageAdjust ,
MorphologicalPerimeter[Image[A0], 0.4]}
{Image[A2], LaplacianFilter[Image[A2],1] //ImageAdjust,
MorphologicalPerimeter[Image[A2], 0.4]}
{Image[A4],LaplacianFilter[Image[A4],1]//ImageAdjust,
MorphologicalPerimeter[Image[A4], 0.4]}

Binarize[Image[(A4-A2)^2] // ImageAdjust, 0.2]
{Binarize[GradientFilter[Image[A0], 1] //ImageAdjust, 0.08],Binarize[GradientFilter[Image[A2], 1] //ImageAdjust, 0.08],Binarize[GradientFilter[Image[A4], 1] //ImageAdjust, 0.08]} 
(*{ImageFilter[MedianDeviation[Flatten[#]]&,Image[A0],2]// ImageAdjust,
ImageFilter[MedianDeviation[Flatten[#]]&,Image[A2],2]// ImageAdjust,
ImageFilter[MedianDeviation[Flatten[#]]&,Image[A4],2]// ImageAdjust}*)
(*ListPlot3D[B0, Mesh-> All,ViewPoint->Above]
ListPlot3D[A2, Mesh-> All,ViewPoint->Above]
ListPlot3D[A4, Mesh-> All,ViewPoint->Above]*)