character segmentation

hi, i have obtained this code from a website,for character segmentation, i am unable to understand a particular line in this code , could any body explain me...

code:-

clear all;

close all;

I = imread('plate.jpg');

BW = im2bw(I, 0.9);

BW = ~BW;

stats = regionprops(BW);

for index=1:length(stats)

if stats(index).Area > 200 && stats(index).BoundingBox(3)*stats(index).BoundingBox(4) < 30000

      x = ceil(stats(index).BoundingBox(1))
      y= ceil(stats(index).BoundingBox(2))
      widthX = floor(stats(index).BoundingBox(3)-1)
      widthY = floor(stats(index).BoundingBox(4)-1)
      subimage(index) = {BW(y:y+widthY,x:x+widthX,:)}; 
      figure, imshow(subimage{index})
      end
  end

what does this line do:

if stats(index).Area > 200 && stats(index).BoundingBox(3)*stats(index).BoundingBox(4) < 30000

Answer 1

[Walter Roberson]

See http://www.mathworks.com/help/toolbox/images/ref/regionprops.html#bqkf8hf

For a 2 dimensional image, BoundingBox(3) will be the x width and BoundingBox(4) will be the y width of the bounding box.

The Area is the actual number of pixels in the region; the product of the widths is the number of pixels that are within the bounding box.

[Ashish]

Thank you for the answer, could u also tell me what boundingbox(1) n boundingbox(2) stand for.

[Matt Fig]

I deleted my answer because I misread your code. Please accept Walter's answer, as he got it right...

[Walter Roberson]

As indicated in that link, they are the x and y coordinates of the upper-left corner of the bounding box.

[Ashish]

Thanks Matt and Walter, my doubt is now cleared.

[vinod ch]

what does the boundingBox contains can you explain it briefly about this code... i mean how it was able to detect exactly it is the character and on what parameters it separated them. can you explain me

[ezhil K]

I have used the same code.But,I get error as follows:

Error:

Reference to non-existent field 'Area'.

Error in Shi_tomashi (line 142)

if stats(index).Area > 100 && stats(index).BoundingBox(3)*stats(index).BoundingBox(4) < 30000

How should I resolve this?

Answer 2

[SATYAVIR SINGH KUNTAL]

@ashish.. could u give me the link of the site from which u got this piece of code... thanxx..

[Ashish]

Here is the link:

http://stackoverflow.com/questions/5305712/how-to-perform-character-segmentation-in-matlab

there is a sample image along with the code.