mmdlabeltext
Segmenting letters, words and paragraphs.

The text image is read.

>>> f = mmreadgray('stext.tif')

>>> mmshow(f)

f

The letters are the main connected components in the image. So we use the classical 8-connectivity criteria for identify each letter.

>>> fl=mmlabel(f,mmsebox())

>>> mmlblshow(fl)

fl

The words are made of closed letters. In this case we use a connectivity specified by a rectangle structuring element of 7 pixels high and 11 pixels width, so any two pixels that can be hit by this rectangle, belong to the same connected component. The values 7 and 11 were chosen experimentally and depend on the font size.

>>> from Numeric import ones

>>> sew = mmimg2se(mmbinary(ones((7,11))))

>>> mmseshow(sew)

array([[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
       [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]],'1')

>>> fw=mmlabel(f,sew)

>>> mmlblshow(fw)

fw

Similarly, paragraphs are closed words. In this case the connectivity is given by a rectangle of 35 by 20 pixels.

>>> sep = mmimg2se(mmbinary(ones((20,35))))

>>> fp=mmlabel(f,sep)

>>> mmlblshow(fp)

fp