Re: Core Image in FxPlug example
Re: Core Image in FxPlug example
- Subject: Re: Core Image in FxPlug example
- From: Brian Gardner <email@hidden>
- Date: Wed, 29 Apr 2009 01:15:53 -0700
Hi Darrin.
Thank you for your examples. Very helpful.
Is there any example source code for
the Displacement Distortion CI filter which you mention below?
Which samples 3 pixels from one image,
and 1 pixel from another image?
That would be very helpful for me to see.
There are very few examples which use
multiple (or reference) images,
and take multiple samples per image.
Is there any such sample code available?
(Like of the Displacement Distortion filter you describe, below.)
-- Brian
On Apr 28, 2009, at 9:01 AM, Darrin Cardani wrote:
Glad it helps! It looks to me like Displacement Distortion is using
the magnitude and direction of edges in the map image to offset
pixels in the source image. I believe it first converts the map
image to grayscale, then finds the difference of each pixel with its
neighbors in the x and y directions. It multiplies the x and y
differences by the scale parameter and uses the resulting vector as
an offset from the current pixel in the source image.
So let's say the grayscale version of your map image looked like this:
0.75 0.89
0.23 0.52
It takes (0.75 - 0.89) = -0.14 as the x offset
It takes (0.75 - 0.23) = .52 as the y offset
It then multiplies those values by the scale parameter. Let's say
it's set to 25, so it comes up with an offset of (-3.5, 13). It adds
that to the current (x,y) coordinate and samples the input image at
(x - 3.5, y + 13).
Does that make sense?
Darrin
On Apr 27, 2009, at 5:53 PM, Patrick Sheffield wrote:
Thank you Darrin - this helps a lot.
I wonder if you could shed some light on a specific CoreImage
filter - specifically DisplacementDistortion...
In Shake and in FxScript, the X-Displacement is governed by one
channel in the displace image and the Y-Displacement by another. I
can't find any documentation on the CI filter as to how it handles
this.
Thanks,
Patrick
--
Darrin Cardani
email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Pro-apps-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Pro-apps-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden