(a) In a character recognition application, text pages are reduced to binary form using a...

(a) In a character recognition application, text pages are reduced to binary form using a thresholding transformation function of the form shown in Fig. 3.2(b). This is followed by a procedure that thins the characters until they become strings of binary 1s on a background of 0s. Due to noise, the bina-rization and thinning processes result in broken strings of characters with gaps ranging from 1 to 3 pixels. One way to “repair” the gaps is to run an averaging mask over the binary image to blur it, and thus create bridges of nonzero pixels between gaps. Give the (odd) size of the smallest averaging mask capable of performing this task.

FIGURE 3.2 Intensity Transformation functions. (a) Contraststretching function. (b) Thresholding function.

---

(b) After bridging the gaps, it is desired to threshold the image in order to convert it back to binary form. For your answer in (a), what is the minimum value of the threshold required to accomplish this, without causing the segments to break up again?