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Re: how many array elements with a certain value in a row [message #70275 is a reply to message #70273]

Thu, 01 April 2010 06:17

ben.bighair
Messages: 221
Registered: April 2007

Senior Member

On Apr 1, 9:02 am, David Fanning <n...@dfanning.com> wrote:
> Jeremy Bailin writes:
>> Does anyone have a nice simple efficient solution to this problem (I
>> have a simple inefficient solution and a vague sketch in my mind of a
>> convoluted but probably efficient solution):
>
>> I have an image in which many pixels are saturated (=65535, they're
>> short unsigned). I want to treat each set of consecutive saturated
>> pixels in a row as a single unit and know how many saturated pixels in
>> a row there are. So I would like to have a list that contains (a) the
>> rightmost pixel of each set of consecutive saturated pixels, and (b)
>> how many saturated pixels there were in the set.
>
> I'm guessing you could probably work something out with
> LABEL_REGION. As for efficiency...

Hi,

That sounds right. I recall HISTOGRAM scans left to right along rows.
So a histogram of the labeled image coupled with the reverse indices
and a row look-up function to convert from index to row should provide
enough info.

Is this like a run-length-encoding you're looking for?

Cheers,Ben

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[Message index]

		Re: how many array elements with a certain value in a row By: jeanh on Thu, 01 April 2010 08:22
		Re: how many array elements with a certain value in a row By: Jeremy Bailin on Thu, 01 April 2010 08:11
		Re: how many array elements with a certain value in a row By: Chris W on Thu, 01 April 2010 07:14
		Re: how many array elements with a certain value in a row By: Jeremy Bailin on Thu, 01 April 2010 06:56
		Re: how many array elements with a certain value in a row By: Chris W on Thu, 01 April 2010 06:48
		Re: how many array elements with a certain value in a row By: Jeremy Bailin on Thu, 01 April 2010 06:40
		Re: how many array elements with a certain value in a row By: ben.bighair on Thu, 01 April 2010 06:17
		Re: how many array elements with a certain value in a row By: Gray on Thu, 01 April 2010 06:03
		Re: how many array elements with a certain value in a row By: David Fanning on Thu, 01 April 2010 06:02

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