Re: Gold resolution
Re: Gold resolution
- Subject: Re: Gold resolution
- From: "Adriano Von Markendorf" <email@hidden>
- Date: Sat, 9 Mar 2002 18:35:34 -0300
Thomas wrote:
>
> Whoever "proved" this does not understand PostScript halftone
>
> screening algorithms. PostScript shapes dots within each halftone
>
> cell based on the high resolution image data.
and Roberto wrote:
>
I believe there's an incomplete picture on each view here.
>
>
Those people who 'prove' the futility of data over 1.4x, as Thomas said,
>
don't understand Postscript screening.
>
Thomas, on the other hand, is limiting his comment to the screening
>
algorithm on a single color plate, and he is right on his assertion in
that
>
context, but that doesn't propagate fully into color reproduction.
I see.
>
In a single color, the fact that PS cuts each halftone dot to the high-res
>
data, would amount to 3x holding more detail than 2x holding more than
1.4x.
>
And in fact, you might probably see eyelashes that are smaller than the
>
screening cell.
>
But when you add up the other colors, forming a rosette, the detail is
lost
>
because of the spatial dispersion of the samples ("pointillist effect")
that
>
is the basis of halftone color.
>
Similar than talking about megapixels on digital cameras. As each pixel is
>
tinted only a single primary color (RGB), the spatial resolution is less
>
than stated. Except for three-shot cameras that are almost inexistent now.
>
In printed halftone color, each halftone dot is a single ink, and it's the
>
combination of the four inks which makes the visual 'unit'.
Really, I didn't think on this way..!
>
But strong contrast details, however (ie black hairline), can to some
extent
>
go past the resolution limitation and benefit from 2x or maybe even 3x.
>
And careful choice of angles and dot shapes can also improve the detail in
>
specific images.
Really - II
>
And finally, stochastic screening blows past everything. At even 30 micron
>
stochastic, a 600dpi scan looks definitively better than a 300dpi one and
of
>
course 300dpi way better than 150dpi.
For sure. I was knowed that in stochastic scenario.
Well, thank's for Bruce, Thomas, Neil and you Roberto !
I hope that now I got the entirely picture.
Very nice weekend to all...
Adriano von Markendorf email@hidden
"I-C-Cm vitamin's inside" Rio de Janeiro - Brazil
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