John,
I think you are misunderstanding how camera phones with "digital zoom"
accomplish the zooming. Digital zoom is fake zoom. It is done by simple
cropping the center section of the full frame, and then that cropped section
is resized and interpolated to fill the frame. Interpolation means the
camera makes up data to fill in the missing pixels which are now stretched
out over a wider area. As a result, you lose resolution, sharpness, detail.
The same thing occurs whether you do the cropping & resizing in Photoshop,
or if you use your phone's "digital zoom" feature, but the interpolation
algorithms in Photoshop are superior to those in phones or consumer
digicams, so you'll get better results if you do the cropping and resizing
in post-processing using a proper image editor.
I know what I'm talking about. This stuff is my job. :-)
See:
www.PhotoFixPro.com
I've been meaning to post my observations about the Pre's camera. I'll try
to get to that later today.
George
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of John
Messeder
Sent: Saturday, February 06, 2010 9:56 AM
To: [email protected]
Subject: Re: [Treo] webOS suggestions for Palm - "official" nomination
thread
Let's say, to make up some easy numbers, the camera shoots a 3Mp
picture. Whatever it sees, it spreads across all 3 million pixels -
whether that's the full cubicle or the face of the person working there.
What makes the picture look closer, whether by optical or digital zoom,
is that the face takes up more space in the frame.
Taking more space in the frame means that the face now uses the
same 3 million pixels that in a wider shot recorded the entire cubicle.
That's part of why digital lenses talk about magnification rather
than focal length, and why a 300mm digital zoom lens on my Nikon digital
is "equivalent" to a 450mm lens on my old FM.
But if I shoot wide and crop in PS, I actually remove a bunch of
pixels from the pic. To get the size back, I have to add pixels, and
that means PS has to interpolate colors and detail as it makes the
transition to give me back a portion of the original pic in the original
3Mp size.
That said, it can be done, and the result isn't really terrible,
especially for newsprint and online reproduction. But it's better if the
camera uses all the pixels it has in the shot, rather than doing the
conversion in PS.
On 2/6/2010 10:43 AM, Don Ferguson wrote:
> Yep, but my point is that with digital (rather than optical) zoom, the
same
> thing happens whether it's on the camera or in PS.
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