Counting number of object in an PNG image

[hs.khan47]

Hi everyone im new to Image magic and image processing
i have a test image
http://binarylabsolutions.com/hs/imgs-test/cam2.jpg

and after performing some operation via php imagic interface i converted the image into this

http://binarylabsolutions.com/hs/imgs-t ... 2_cam2.jpg
http://binarylabsolutions.com/hs/imgs-t ... m2.jpg.png

now i just want to count the number of white objects in the image
like in this example the answer will be "8"
-----------------------------------------------------

there was an old threat on this form which has been deleted and buts it was kind of same problem
https://imagemagick.org/discourse-serve ... hp?t=28856

however fortunately i had copy the command

var_dump(
exec("convert out.pbm -define connected-components:verbose=true -define connected-components:area-threshold=50 \ -connected-components 4 -auto-level -depth 8 test.png")
);

but this is not working form me

help please !!

[snibgo]

I'll assume the important image is 3_cam2.jpg.png, which is a PNG with transparency.

"connected-components" does the job. We ignore the transparency ("-alpha off"). The image is noisy, so we ignore connected components of less than, say, 50 pixels. We don't save the resulting image (we save it to "NULL:").

Code: Select all

convert 3_cam2.jpg.png -alpha off -define connected-components:verbose=true -define connected-components:area-threshold=50 -connected-components 4 NULL:

The text output is:

Code: Select all

Objects (id: bounding-box centroid area mean-color):
  0: 665x500+0+0 331.7,240.7 294764 gray(0)
  247: 129x103+82+378 150.2,430.1 10520 gray(255)
  246: 142x100+475+350 541.9,400.2 10169 gray(255)
  244: 97x64+132+232 181.7,263.9 4811 gray(255)
  238: 107x60+434+216 484.1,245.9 4797 gray(255)
  186: 76x40+162+145 200.9,164.4 2470 gray(255)
  176: 80x40+400+125 438.6,145.1 2413 gray(255)
  83: 60x28+185+75 215.3,88.4 1367 gray(255)
  55: 63x25+384+63 413.7,75.3 1189 gray(255)

We see that one component is black and the rest are white. A suitable Unix text filter will count the lines with "gray(255)".

You are using convert within PHP or something, so you need to write the text to an array or something.

[fmw42]

Please, always provide your IM version and platform when asking questions, since syntax may differ. Also provide your exact command line and if possible your images.

See the top-most post in this forum "IMPORTANT: Please Read This FIRST Before Posting" at http://www.imagemagick.org/discourse-se ... f=1&t=9620

If using Imagemagick 7, then see http://imagemagick.org/script/porting.php#cli


For novices, see

http://www.imagemagick.org/discourse-se ... f=1&t=9620
http://www.imagemagick.org/script/comma ... essing.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/
https://github.com/ImageMagick/usage-markdown