how to extract text using opencv and pytesseract python?

Question

I am using labelImg to draw a rectangle on the rows of image. Which gives me the xml file . With the help of this xml how to extract that text from the image table . To extract the text I have used the horizontal and vertical ine detection but do not get good result. Now I am using the labelImg which gives me the points of that text which want to extract but I do not know how to apply the method for this .Please tell me how to do that ?

My xml file :

    <annotation>
      <folder>Test Images</folder>
      <filename>FreKa.jpg</filename>
      <path>/home/sumit/Desktop/office_works/Fusion_Code/BIS_Final/Test Images/FreKa.jpg</path>
      <source>
         <database>Unknown</database>
        </source>
      <size>
         <width>679</width>
         <height>341</height>
         <depth>3</depth>
         </size>
         <segmented>0</segmented>
       <object>
         <name>Contact Type</name>
         <pose>Unspecified</pose>
         <truncated>1</truncated>
         <difficult>0</difficult>
         <bndbox>
           <xmin>1</xmin>
           <ymin>100</ymin>
           <xmax>678</xmax>
           <ymax>157</ymax>
        </bndbox>
       </object>
       </annotation>

My input images :

how to extract the contract type from the table with the help of the xml file ? Thanks...

Answer 1

To get xmin you can use xpath() with '//annotation/object/bndbox/xmin' or even shorter '//xmin'

It always gives list (even if there is only one element or there are no elements) so it will need [0] to get first element or for-loop to work with all elements.

Using if list_of_elelemts: ... you can run code only when list has some elements.

You can also use len() to check how many elements you get.

text = '''
<annotation>
  <folder>Test Images</folder>
  <filename>FreKa.jpg</filename>
  <path>/home/sumit/Desktop/office_works/Fusion_Code/BIS_Final/Test Images/FreKa.jpg</path>
  <source>
     <database>Unknown</database>
  </source>
  <size>
     <width>679</width>
     <height>341</height>
     <depth>3</depth>
  </size>
  <segmented>0</segmented>
  <object>
     <name>Contact Type</name>
     <pose>Unspecified</pose>
     <truncated>1</truncated>
     <difficult>0</difficult>
     <bndbox>
       <xmin>1</xmin>
       <ymin>100</ymin>
       <xmax>678</xmax>
       <ymax>157</ymax>
     </bndbox>
  </object>
</annotation>
'''

import lxml.etree

tree = lxml.etree.fromstring(text)

print('xmin:', tree.xpath("//annotation/object/bndbox/xmin")[0].text)
print('xmin:', tree.xpath("//bndbox/xmin")[0].text)
print('xmin:', tree.xpath("//object//xmin")[0].text)
print('xmin:', tree.xpath("//xmin")[0].text)

print('xmin:', tree.xpath("//xmin/text()")[0])  # with `text()` instead of `.text`

for item in tree.xpath("//xmin/text()"):
    print('xmin:', item)  # with `text()` instead of `.text`

objects = tree.xpath("//object")
print('len(objects):', len(objects))

other = tree.xpath("//bndbox/other")
if other:
    print('found', len(other), 'elements')
else:
    print('there is no "other" elements')