15 Feb
2002
15 Feb
'02
3:29 a.m.
On Fri, 15 Feb 2002, Christopher Smith wrote:
Actually the resolution is really about 1/3 the stated "Megapixel
resolution", especially if you take pictures of things with high spatial
frequency (say fine pitch IC leads) This is because the stated resolution
neglects to mention that the three color pixels in a group are counted as
individual pixels -- basically a X resolution B/W sensor behind a color filter
array is called a X resolution color sensor, but it really isn't...
filtering after the fact attempts to fix the artifacts, but makes a
mess out of high spatial frequency images that would have been ok if the
camera really had the stated resolution....
Peter Wallace
-----Original
Message-----
From: Doc [mailto:doc@mdrconsult.com]
What's happening more and more, though, is
a long pseudotechnical
mis-explanation of the part's function. I was looking at digital
I love those. :) See my previous comment about the composite video
input.
cameras last year, and asked the salesperson at
the camera
counter what
3.2 megapixels translates to in terms of resolution and color
depth. He
I always assumed megapixel was referring to the number of pixels at
a fixed color depth (probably 24-bit)... I'm certain that it's just
a manufactured slang term to make digital cameras sound more impressive
and annoy people who know what they're talking about.
Chances are that we're either talking about 1024 * 1024 pixels, or 1000
* 1000 pixels, in which case 3.2 megapixels gives one a resolution of
something like:
3355443.2 (?) pixels -- that's using 1024, so it's probably incorrect :)
(The .2 of a pixel makes me wonder)
3200000 (Sounds better to me, so it's based on 1000s)
A square picture of 1789 * 1789 would be slightly larger than this. You
can probably assume some kind of a rectangular aspect ratio, though. I
would guess that a normal camera is something around 1.5 (wide) to 1,
but I don't really feel like calculating that. ;) explained to me at length that megapixels was a
measure of "how many
pictures you can take on one smartcard"
Not being busy that day, and being unduly irritated by his
condescension, I made him repeat himself in front of the
store manager.
I don't know if the manager cared at all, but it made _me_ feel much
better.
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl
Hacker.")."\x08!\n");
'