TOCR does not currently support OCRing of zones (regions of a page); it will always OCR the whole image. If you wish to OCR zones then you should either:

a) OCR the whole image and extract characters based on the positional information returned or
b) Copy the zones to a new image and OCR the new image.

Accuracy is usually much improved if all the zones are OCR’d at once rather than OCRing the zones individually. To do this copy the zones to a clean image and separate them vertically, with lots of white space.