Re: Digital images & pixels
Wonderful.
So what?
"bagal" <alan_plc@hotmail.com> wrote in message
news:O74nc.78$Nc3.32@newsfe3-win.server.ntli.net...
: Hi I am new here and am looking for a discussion forum to sound out some
: preconceptions I have about digital imaging.
:
: 1 - pixels have finite dimension (whatever it may be on PDA, computer or
: large screen display a sports ground)
: implication:
: (a) digital image resolution is best optimised on a 1 to 1 basis
: therefore aiming for 6x4 or 7x5 prints with mucho megapixels is really a
bit
: of over the top-ness
:
: (b) digital signal processing (in essence maths algorithms) are essential
if
: image reproduction move from a 1-2-1 display. Why? Well, if showing a
2000
: by 1000 images on a display of 4000 by 2000 either the pixels have to be
: 'enlarged' to fill 2 pixel places along and 2 pixel places up. So in
this
: example 1 ordinary pixel now fills the space of 4 ordinary pixels (I bet
: this is what is called pixellation)
:
: (b2) maybe there is another way - let's call it interpolation. Instead of
1
: image pixel filling the space taked by 4 display pixels we'll use a bit of
: linear math to fill in the bits in between. So the original image pixels
: now fill 1 display pixel space but they are surrounded by fill-in values
: determined by a linear math algorithm.
:
: (c) going the other way, from a 2000 by 1000 image to a 300 by 200
display.
: Now we have far too many pixels in the image Rougly 5 times too many So
the
: display shows 1 pixel from the image, discards the next 4 image pixels and
: so on ... till the display space is filled.
:
: OK - what am I getting at?
:
: Well, the first thing is the importance of a bit of linear math, Image
: processing algorithms seem pretty darned important.
:
: Then there are interference effects. Remember all thos lovely patterns
: generated by repeating certain equations again, again and again (it used
to
: be called chaos or fractal math) Well, there is a possibility that
: particular image patters might generate interference
:
: To me - speaking naively - this suggests that tonal as opposed to colour
: display of images is the kernel of a good CCD. Can it handle tonal
: variation as well as changes in hue and colour?
:
: ?
:
: the bagal
:
:
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