To build a workspace to experiment with the Change Homotopy operator:
Choose Gaussian Noise from Generate Noise in option Input/Output. Use Width = 20, Height = 1, Mean = 50 and Variance = 20.
Choose the AdaptativeThreshold (mmach) of an Image, set the lower threshold level to 60 and the upper threshold level to 255 and apply it to the generated noise.
Apply the morphological Negation to the result of the threshold.
Do the Intersection of the base image and the previos result.
Generate a 3x3 Str.El. Flat Structuring Element like the following:
0 0 0
1 1 1 Structuring element used
0 0 0
Apply the Closing by Reconstr. operator using as first input the result of the intersection, as second input the result of the negation and as third input the structuring element.
Visualize the result using the Plot Display 2D in Visualization.
Exercises
Use the editimage anotation tool to build markers for the faces of the
block of the image $MMACH/viff/block1.xv. Apply the change of homotopy
operator to the gradient of the block image.
Compare the gradient image with the image obtained after the change of
homotopy. What are the differences between the two images?
Compute the gradient of the negation of the distance function of the
image $MMACH/viff/blobs1.xv. Use the editimage anotation tool to
build markers for each cell in this image. Perform the change
of homotopy of the gradient.
Compare the gradient image with the image obtained after the change of
homotopy. What are the differences between the two images?