Prev: New search engine
Next: I need a linux distribution with a specific bug fixed in thekernel
From: unruh on 4 Dec 2009 01:14
["Followup-To:" header set to alt.os.linux.]
On 2009-12-04, Anita <me(a)invalid.com> wrote:
> I quoted and wrote in message news:7nri6tF3kdfmiU1(a)mid.individual.net...
>
>>>> It begs the question: precisely what "measuremenst" are required?
>>>
>>> Since you asked.
>>> There is a bright line in the frame which is a laser sheet reflected from
>>> the tops of the waves. We need to measure their height very accurately.
>>
>> And how will you accomplish that sort of "very accurate" measurement using
>> the method you (very loosely) suggest? Cropping the image, converting
> image
>> format et. al. will most assuredly result in various losses of
> information,
>> and pixels are not any sort of accurate measurement of anything other than
>> pixels.
> I neglected to mention that the original *.mov, as well as the instrument
> that captured the "Quicktime" image, will render unacceptable mensuration
> parameters into the mix.
>

Yup. Which was why I asked what the format of the of the .mov file.
the instrument that captured the image is called a camera.

>
>
>
From: Anita on 4 Dec 2009 02:08
"unruh" <unruh(a)wormhole.physics.ubc.ca> wrote in message
news:slrnhhha2i.8k9.unruh(a)wormhole.physics.ubc.ca...

>>> There is a bright line in the frame which is a laser sheet reflected
from
>>> the tops of the waves. We need to measure their height very accurately.
>>
>> And how will you accomplish that sort of "very accurate" measurement
using
>> the method you (very loosely) suggest? Cropping the image, converting
image
>> format et. al. will most assuredly result in various losses of
information,
>
> Which is why I am converting to png, a lossless format. Cropping is OK
> since it is relative changes which are important. Pixels, when
> calibrated are a fine measure.
>
>> and pixels are not any sort of accurate measurement of anything other
than
>> pixels.
>
> You think the pixels move around, or breathe?

I know that the rendition of coherent light into relatively large formatted
pixels after passing through a lens is a gross approximation particularly
when dealing with laser light, but feel free to mark with chalk, measure
with a micrometer and then round (or truncate) it to the nearest pixel...
the comparison is an apt one.

Good luck, you're going to need it.


First  |  Prev  | 
Pages: 1 2 3 4 5
Prev: New search engine
Next: I need a linux distribution with a specific bug fixed in thekernel