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From: Roshan Rajaratnam on 2 May 2010 14:33
guys can someone help me to find the height of a signature in which im so clueless.
From: John D'Errico on 2 May 2010 14:49
"Roshan Rajaratnam" <rajaratnam_roshan(a)yahoo.com> wrote in message <hrkggv$r7f$1(a)fred.mathworks.com>...
> guys can someone help me to find the height of a signature in which im so clueless.

1. Steal some code that finds the width of a signature.

2. Rotate the signature by 90 degrees.
From: ImageAnalyst on 2 May 2010 16:45
On May 2, 2:33 pm, "Roshan Rajaratnam" <rajaratnam_ros...(a)yahoo.com>
wrote:
> guys can someone help me to find the height of a signature in which im so clueless.

------------------------------------------------------
Use the sum function to sum along the columns (2) direction. Then
pick some threshold to find where the sum dips below some level. Use
that with the find() function to find the first and last row where
your sum is less than your threshold (assuming the signature is dark
on a light background).
verticalProfile = sum(sigImage, 2);
startRow = find(verticalProfile < thresholdValue, 1, 'first');
endRow = find(verticalProfile < thresholdValue, 1, 'last');
sigHeight = abs(endRow-StartRow);
It might get more complicated than that, (like if the signature is
rotated, or it's a color image, etc.) but that's basically it.
Hopefully this will give you a clue now to get started and make it
more robust....
From: Roshan Rajaratnam on 13 May 2010 22:23
ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message <acc97da8-b8c8-40ff-8f30-c06d377c6390(a)a34g2000yqn.googlegroups.com>...
> On May 2, 2:33 pm, "Roshan Rajaratnam" <rajaratnam_ros...(a)yahoo.com>
> wrote:
> > guys can someone help me to find the height of a signature in which im so clueless.
>
> ------------------------------------------------------
> Use the sum function to sum along the columns (2) direction. Then
> pick some threshold to find where the sum dips below some level. Use
> that with the find() function to find the first and last row where
> your sum is less than your threshold (assuming the signature is dark
> on a light background).
> verticalProfile = sum(sigImage, 2);
> startRow = find(verticalProfile < thresholdValue, 1, 'first');
> endRow = find(verticalProfile < thresholdValue, 1, 'last');
> sigHeight = abs(endRow-StartRow);
> It might get more complicated than that, (like if the signature is
> rotated, or it's a color image, etc.) but that's basically it.
> Hopefully this will give you a clue now to get started and make it
> more robust....

what do u mean by the threshold value in this example? can someone help me in this please?
From: ImageAnalyst on 13 May 2010 22:26
On May 13, 10:23 pm, "Roshan Rajaratnam"
> what do u mean by the threshold value in this example? can someone help me in this please?
-------------------------------------------------------------
It's just an intensity value that divides the background from the
foreground. Just use plot() to plot the vertical profile and you'll
see what I mean. It will be bright (high,say 200 gray levels) for all
rows except where there is a signature where the profile will be
darker, say only 150 or so. So the threshold might be 175.

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Next: how to get random sequence from pulse generator in sample based pulse type