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Computing a skeleton

First, we declare some operators.

    CMMFile File
    CAlgebre algebre
    CCAlgebre calgebre
    CBasic basic
    CMorpho6c Morpho6c
    CMorpho4c Morpho4c
    CMorpho8c Morpho8c

Then, we create a Tcl proc for computing the skeleton. The idea is to use the skeleton_anchor with as anchor points the maxima of the distance function. We are going to write a procedure which has as argument the connectivity. The default is 6c, the 6-connectivity.

    proc skeleton {img {con 6c}} {

Then compute the distance

            CImageGrey dist -this [Morpho$con chamfer [$img cget -this]]

Take the maxima that are included in the object.

            CImageGrey max1 -this [Morpho$con localMaximum [dist cget -this]]
            CImageGrey max -this [algebre mult [max1 cget -this] [$img cget -this]]

Then compute the skeleton

            CImageGrey skel -this [Morpho$con skeleton_anchor [$img cget -this] [max cget -this]]

and stretch the image so that we can see the results

            CImageGrey resskel$con -this [basic stretch [skel cget -this]]

and write the results on the disk

            File PGMWrite [resskel$con cget -this] skeleton$con.pgm

Then free the memory

            deletePtr dist
            deletePtr max
            deletePtr max1
            deletePtr resskel$con
            deletePtr skel
    }

We will compute the skeleton on an image

    CImageGrey img -this [File PGMRead shape2.pgm]

and compute the skeleton

    skeleton img 6c

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