| polyfill on postscript: hairy with hairlines [message #76609] |
Tue, 21 June 2011 14:08  |
MarioIncandenza
Messages: 231
Registered: February 2005
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Senior Member |
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So, for a precision application, I resorted to the nuclear option of
plotting each point with a POLYFILL, rather than leaving that up to
CONTOUR, IMAGEMAP, etc.
Got what I wanted in terms of precision, but the polygons in the
PostScript file have hairlines around them. When the image is shrunk,
the hairlines result in ugly aliasing.
What bothers me most is that these lines are a particular shade of
gray, that I didn't think was available when POLYFILL is called-- that
is, it's not in the color table.
Has anyone found a solution/workaround for this?
--Edward H.
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| Re: polyfill on postscript: hairy with hairlines [message #76692 is a reply to message #76609] |
Wed, 22 June 2011 11:40  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Ed Hyer writes:
> Yup! As per usual, the question had already come up, and been
> ImageMagick behave properly?" Which is also answered in that article!
Coyote has always claimed he is clairvoyant. :-)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thue. ("Perhaps thou speakest truth.")
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| Re: polyfill on postscript: hairy with hairlines [message #76693 is a reply to message #76609] |
Wed, 22 June 2011 11:34 |
MarioIncandenza
Messages: 231
Registered: February 2005
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Senior Member |
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On Jun 22, 7:10 am, Andy Heaps <a.j.he...@reading.ac.uk> wrote:
> Hi Ed,
> doeshttp://www.idlcoyote.com/ps_tips/psstripes.htmllook like the
> problem you're having?
Yup! As per usual, the question had already come up, and been
answered. As I read the solution, I thought, "OK, but how do I make
ImageMagick behave properly?" Which is also answered in that article!
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| Re: polyfill on postscript: hairy with hairlines [message #76700 is a reply to message #76609] |
Wed, 22 June 2011 07:10 |
Andy Heaps
Messages: 22
Registered: March 2006
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Junior Member |
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Hi Ed,
does http://www.idlcoyote.com/ps_tips/psstripes.html look like the
problem you're having?
Cheers
Andy
On 21/06/11 23:34, Ed Hyer wrote:
> On Jun 21, 2:22 pm, "Kenneth P. Bowman"<k-bow...@null.edu> wrote:
>> Are you using PS or PDF? On a Mac by any chance?
>
> I am using the PS driver on Linux.
> The hairlines may be "rendering artifacts," but they are definitely
> present, and the aliasing that comes with them does persist when the
> PS is converted to a PNG.
>
>> The best solution I know of is to use an image instead of
>> line graphics. You can control the resolution of the image
>> and make it chunky or smooth, as you prefer.
>
> I was driven to try this because I got fed up with the imprecision of
> my results using various image-based approaches.
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| Re: polyfill on postscript: hairy with hairlines [message #76707 is a reply to message #76609] |
Tue, 21 June 2011 15:34 |
MarioIncandenza
Messages: 231
Registered: February 2005
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Senior Member |
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On Jun 21, 2:22 pm, "Kenneth P. Bowman" <k-bow...@null.edu> wrote:
> Are you using PS or PDF? On a Mac by any chance?
I am using the PS driver on Linux.
The hairlines may be "rendering artifacts," but they are definitely
present, and the aliasing that comes with them does persist when the
PS is converted to a PNG.
> The best solution I know of is to use an image instead of
> line graphics. You can control the resolution of the image
> and make it chunky or smooth, as you prefer.
I was driven to try this because I got fed up with the imprecision of
my results using various image-based approaches.
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| Re: polyfill on postscript: hairy with hairlines [message #76708 is a reply to message #76609] |
Tue, 21 June 2011 14:22 |
Kenneth P. Bowman
Messages: 585
Registered: May 2000
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Senior Member |
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In article
<f3d8e3f8-3fff-49f3-b1cf-63d04a7a24d5@28g2000pry.googlegroups.com>,
Ed Hyer <ejhyer@gmail.com> wrote:
> So, for a precision application, I resorted to the nuclear option of
> plotting each point with a POLYFILL, rather than leaving that up to
> CONTOUR, IMAGEMAP, etc.
>
> Got what I wanted in terms of precision, but the polygons in the
> PostScript file have hairlines around them. When the image is shrunk,
> the hairlines result in ugly aliasing.
>
> What bothers me most is that these lines are a particular shade of
> gray, that I didn't think was available when POLYFILL is called-- that
> is, it's not in the color table.
>
> Has anyone found a solution/workaround for this?
>
> --Edward H.
Are you using PS or PDF? On a Mac by any chance?
There seem to be some rendering issues with screen display
of PDFs on Macs (and possibly other systems).
The best solution I know of is to use an image instead of
line graphics. You can control the resolution of the image
and make it chunky or smooth, as you prefer.
Ken Bowman
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