Python + OpenCV: OCR Image Segmentation

Question

I am trying to do OCR from this toy example of Receipts. Using Python 2.7 and OpenCV 3.1.

Grayscale + Blur + External Edge Detection + Segmentation of each area

Answer 1

Try using Stroke Width Transform. Python 3 implementation of the algorithm is present here at SWTloc

Install the Library

pip install swtloc

Run the swttransform

from swtloc import SWTLocalizer
from swtloc.utils import imgshowN, imgshow

swtl = SWTLocalizer()
imgpath = ...
swtl.swttransform(imgpaths=imgpath, text_mode = 'lb_df', gs_blurr=False ,
                  minrsw = 3, maxrsw = 10, max_angledev = np.pi/3)
mgshowN([swtl.orig_img, swtl.swt_mat, swtl.swt_labelled3C],
        ['Original Image', 'Stroke Width Transform', 'Connected Components'])

Run the Grouping of texts

respacket = swtl.get_grouped(lookup_radii_multiplier=.8, sw_ratio=2,
                 cl_deviat=[13,13,13], ht_ratio=2, 
                 ar_ratio=4, ang_deviat=30)

grouped_labels = respacket[0]
grouped_bubblebbox = respacket[1]
grouped_annot_bubble = respacket[2]

imgshowN([swtl.orig_img, grouped_annot_bubble],
        ['Original', 'Grouped Bubble BBox Annotation'])

There are multiple parameters in the of the swttransform function and get_grouped function that you can play around with to get the desired results.

Full Disclosure : I am the author of this library