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#### Finding Length/Height in image

```hi all!

i'm new to matlab and i've to use this program as part of my project.

my project requires matlab to:
- find the height of the player from ground to knee level

i'm able to convert the image to a rather clear bw image. however, i do not know how to target at the spot where i want to find the length at.

can someone give some suggestion?
your help would be very much appreciated :)

thanks
```
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serena
3/2/2011 1:05:22 AM
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```On Mar 1, 8:05=A0pm, "serena " <moonstruckseren...@hotmail.com> wrote:
> hi all!
>
> i'm new to matlab and i've to use this program as part of my project.
>
> my project requires matlab to:
> - find the height of the player from ground to knee level
>
> i'm able to convert the image to a rather clear bw image. however, i do n=
ot know how to target at the spot where i want to find the length at.
>
> can someone give some suggestion?
> your help would be very much appreciated :)
>
> thanks

--------------------------------------------------------
Sure.  But first of all, where did you post your image?  Give the URL
to the web hosting site where you uploaded it, such as one you'd get

Secondly, do you want the height in pixels, or real world units?  If
you want it in real world units, you have to know how many pixels
correspond to 1 cm, such as b y imaging an object of known length like
a ruler.

Third, does it have to be automatic or can it be manual?  If it can be
manual, just call improfile and find the distance in pixels between
the first coordinate and the last coordinate.  Then convert to real
world units if you have a calibration scale factor.  If it has to be
automatic, then you have to segment out your person from the
background somehow, for example by thresholding.  Then sum the array
horizontally to get a vertical profile, and then use find() to find
the row (line) where the segmented person starts and stops (use the
'first' and 'last' option in find()).  Then convert to real world
units if required.

So if you have any more questions, post your image and your code and
clearly and unambiguously describe what the trouble is.
-ImageAnalyst
```
 1
ImageAnalyst
3/2/2011 1:49:26 AM
```> --------------------------------------------------------
> Sure.  But first of all, where did you post your image?  Give the URL
> to the web hosting site where you uploaded it, such as one you'd get

> Secondly, do you want the height in pixels, or real world units?  If
> you want it in real world units, you have to know how many pixels
> correspond to 1 cm, such as b y imaging an object of known length like
> a ruler.
i would want the height in real world units eventually.
how would i be able to find out how many pixels correspond to 1 cm?
referring to my image link above, i do know the length of the stick (if there is a need for a known length in the image?)

> Third, does it have to be automatic or can it be manual?  If it can be
> manual, just call improfile and find the distance in pixels between
> the first coordinate and the last coordinate.  Then convert to real
> world units if you have a calibration scale factor.  If it has to be
> automatic, then you have to segment out your person from the
> background somehow, for example by thresholding.  Then sum the array
> horizontally to get a vertical profile, and then use find() to find
> the row (line) where the segmented person starts and stops (use the
> 'first' and 'last' option in find()).  Then convert to real world
> units if required.

at the moment, going step by step, it would be manual.

> So if you have any more questions, post your image and your code and
> clearly and unambiguously describe what the trouble is.
> -ImageAnalyst
i'll give it a try, i'm sure i'll be back here ;)
thanks ImageAnalyst!
```
 0
serena
3/2/2011 2:16:06 AM
`plz serena send me cod eif u hav`
 0