POV-Ray : Newsgroups : povray.binaries.images : Halftones by physical subtraction Server Time
28 Mar 2024 15:58:40 EDT (-0400)
  Halftones by physical subtraction (Message 1 to 8 of 8)  
From: Bald Eagle
Subject: Halftones by physical subtraction
Date: 2 Mar 2017 12:30:01
Message: <web.58b8564190f83d3c437ac910@news.povray.org>
I had been experimenting with creating some "prints" by laser cutting holes
instead of directly laser-engraving the image file, and came up with an
assortment of methods to experiment with.

The following is a straightforward halftone pattern where the hole size is
proportional to the darkness of the pixel at its center.


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From: Bald Eagle
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 12:35:01
Message: <web.58b857792ed17a0bc437ac910@news.povray.org>
Another.


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From: Bald Eagle
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 12:40:01
Message: <web.58b8587b2ed17a0bc437ac910@news.povray.org>
Another method I thought might speed up the cutting was overlaying a grid onto a
slice of a heightfield.  Some details and contours are better preserved this
way, although some of the floating "islands" will end up as part of the waste.


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From: William F Pokorny
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 12:46:03
Message: <58b85a5b$1@news.povray.org>
On 03/02/2017 12:33 PM, Bald Eagle wrote:
> Another.
>
Cool! I can imagine people replacing their home/office window and door 
screens with versions having images made in this way... :-)

Bill P.


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From: Bald Eagle
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 13:05:01
Message: <web.58b85e4e2ed17a0bc437ac910@news.povray.org>
William F Pokorny <ano### [at] anonymousorg> wrote:

> Cool! I can imagine people replacing their home/office window and door
> screens with versions having images made in this way... :-)
>
> Bill P.

That was, to a degree, actually the idea - large screens in a convention area as
decoration / space dividers.
The huge number of holes and the large size made finding a faster way to
substantially achieve the same effect really critical.

There are some neat things one can do with dots / perforations, including
optical illusions such as animation from still images, etc.

Photographs work well if the hole resolution is high enough, and there are ways
to play with the "image processing" - applying functions to the rgb or gray
values before calculating the hole size.

I even managed to create holes using fonts, so for instance, a person's photo
could be 'rendered' using their monogram ...


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From: Stephen
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 13:22:40
Message: <58b862f0$1@news.povray.org>
On 3/2/2017 5:28 PM, Bald Eagle wrote:
> I had been experimenting with creating some "prints" by laser cutting holes
> instead of directly laser-engraving the image file, and came up with an
> assortment of methods to experiment with.
>
> The following is a straightforward halftone pattern where the hole size is
> proportional to the darkness of the pixel at its center.
>

Oh! It reminds me of the old fashioned newspaper print photographs..

Nice.

-- 

Regards
     Stephen


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From: Jim Henderson
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 13:24:13
Message: <58b8634d$1@news.povray.org>
On Thu, 02 Mar 2017 18:22:35 +0000, Stephen wrote:

> On 3/2/2017 5:28 PM, Bald Eagle wrote:
>> I had been experimenting with creating some "prints" by laser cutting
>> holes instead of directly laser-engraving the image file, and came up
>> with an assortment of methods to experiment with.
>>
>> The following is a straightforward halftone pattern where the hole size
>> is proportional to the darkness of the pixel at its center.
>>
>>
> Oh! It reminds me of the old fashioned newspaper print photographs..
> 
> Nice.

That was my thought as well.  Really like it. :)

Jim



-- 
"I learned long ago, never to wrestle with a pig. You get dirty, and 
besides, the pig likes it." - George Bernard Shaw


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From: Stephen
Subject: Re: Halftones by physical subtraction
Date: 2 Mar 2017 14:03:00
Message: <58b86c64$1@news.povray.org>
On 3/2/2017 6:24 PM, Jim Henderson wrote:
> On Thu, 02 Mar 2017 18:22:35 +0000, Stephen wrote:
>
>> On 3/2/2017 5:28 PM, Bald Eagle wrote:
>>> I had been experimenting with creating some "prints" by laser cutting
>>> holes instead of directly laser-engraving the image file, and came up
>>> with an assortment of methods to experiment with.
>>>
>>> The following is a straightforward halftone pattern where the hole size
>>> is proportional to the darkness of the pixel at its center.
>>>
>>>
>> Oh! It reminds me of the old fashioned newspaper print photographs..
>>
>> Nice.
>
> That was my thought as well.  Really like it. :)
>

Yes so do I. And now it is retro artistic. :)

Actually a newsprint photo was the first thing I looked at with my 
Christmas pocket microscope when I was about 10 y.o.

-- 

Regards
     Stephen


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