Does anyone have any suggestions for additional filters? I currently 
have these on the "to-do" list:
highlight/midtone/shadow level adjustment
color_function filter


In development:
find_edges
    The "cartoon-like" filter. It basically works, but still needs a lot 
of work.

patterned_blur
    Blurs the image by an amount controlled by a pigment(the only reason 
it is here is because I haven't tested it yet, it compiled fine. :-) ).


(Mostly) Finished:
stars
    Generates non anti-aliased starsfield on portions on the image with 
a given color.

steps
    Divides smooth gradients of color into separate steps. This might 
make good "terraced" height field landscapes.

normal
    Displays the normal values as rgb colors, scaled into the 0-1 range.

multiply
    Multiplies the image by a given color. I will probably extend it to 
take a pigment.

add
    Adds a given color to the image. I will probably extend it to take a 
pigment.

exponent
    Raises the values of each color channel to a power in the respective 
channel of a given color. I will probably extend it to take a pigment.

clip_colors
    Clips the colors of the image to always be less than a specified 
color. I will probably modify it to take two colors, to clip to a range.

invert
    Inverts the image, using the formula component = 1-component.

blur_matrix
    Also called a convolution matrix(I think). Useful for directional 
blurring, etc.

color_matrix
    Runs the color through a 3*3 matrix. Useful in combination with 
multiply, add, exponent, etc.


I will post the source code soon, hopefully later tonight.

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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Chris Huff wrote:
> 
> Does anyone have any suggestions for additional filters? I currently

  You might want to cruise some of the photoshop plugin sites to see what
other kind of effects might be useful. I have a section dedicated to them
at povray.org -

http://www.povray.org/links/3D_Programs/SoftWare_Graphics-Misc/PhotoShop_and_PSP_Filter_Plugins/

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Look into adding some way of adding sparkles when the color of the pixel
surpasses a user-specified threshold. You know, kinda like lensflares. I
would call that filter "dings". I would also like to suggest that you add
some way of blurring specific objects. You could use this to fake blurred
reflections. Oh, and how about a filter that blurs shadows? That way we
could have area_lights without actually using them.

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On Thu, 27 Apr 2000 20:04:35 -0400, "TonyB"
<ben### [at] panamac-comnet> wrote:

>I would call that filter "dings". 

dings???   Why dings?

( Remove the "7" from 7no### [at] ezwvcom to email me. )

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In article <3908e430@news.povray.org>, "TonyB" 
<ben### [at] panamac-comnet> wrote:

> Look into adding some way of adding sparkles when the color of the pixel
> surpasses a user-specified threshold. You know, kinda like lensflares. I
> would call that filter "dings".

Why "dings"?
This could be a good idea, though...I will try a couple things.


> I would also like to suggest that you add some way of blurring 
> specific objects. You could use this to fake blurred reflections.

The code for object-specific effects is not finished yet, so filters 
can't currently use that feature.


> Oh, and how about a filter that blurs shadows? That way we
> could have area_lights without actually using them.

Probably not possible...there is no way to get shadow data.

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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Chris Huff wrote:
> 
> Does anyone have any suggestions for additional filters? I currently

I use "Levels" a lot to increase contrast. It's very useful for scanned and
rendered images, because the scanner/renderer doesn't always distribute the
colour values very well. That is making the darkest (rgb combined) pixel black
and the lightest white. Could probably implement some means of controlling how
white and how black it should be.

sig.

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Is that because if you "ding" or create a tiny nick in the surface of a
lens or filter, the resulting refraction creates something that looks
like a lens flare?

Glen Berry wrote:

> On Thu, 27 Apr 2000 20:04:35 -0400, "TonyB"
> <ben### [at] panamac-comnet> wrote:
>
> >I would call that filter "dings".
>
> dings???   Why dings?
>
> ( Remove the "7" from 7no### [at] ezwvcom to email me. )

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In article <39095F35.84A14C89@stud.ntnu.no>, Sigmund Kyrre Aas 
<as### [at] studntnuno> wrote:

> I use "Levels" a lot to increase contrast. It's very useful for 
> scanned and rendered images, because the scanner/renderer doesn't 
> always distribute the colour values very well. That is making the 
> darkest (rgb combined) pixel black and the lightest white. Could 
> probably implement some means of controlling how white and how black 
> it should be.

This sounds like the "highlight/midtone/shadow level adjustment" filter 
which is still in the "to-do" list. I would like to make a filter which 
allows you to adjust each of these independantly for each color channel, 
but I don't want to "invent" my own math for the process, I want to use 
whatever is being used in professional programs like Photoshop. If 
anyone has some equations for this...?

Or are you talking about an automatic thing that goes through the image 
looking for the darkest and brightest pixels, and adjusts the image so 
those pixels are black and white? That could be done...

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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No. Because these kinds of lens flares usually make a sound when seen on TV.
For example, the hero smiles and you see and hear the ding on his teeth.
Knowwhatimean?

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Chris Huff wrote:

> 
> Or are you talking about an automatic thing that goes through the image
> looking for the darkest and brightest pixels, and adjusts the image so
> those pixels are black and white? That could be done...

Almost. The Photoshop filter is a bit more complex but I think all those
features would be cumbersome in POV. In Photoshop you can adjust the settings
according to a colour histogram while seeing the preview image. 

"Auto Levels" in Photoshop adjusts each channel so that the reddest gets a 255
red value, the greenest a 255 green, etc. This is not very reliable and more
often than not produces an unwanted tint. 

I suggest the following syntax:

levels { <dark_tint>, <bright_tint> }

If the brightest was <.9,.95,.93> the new value would be:
<.9,.95,.93>/.95*bright_tint

For most "real world" scenes, levels{1,1} would then give good results. I have
to do this manually in Photoshop, adjusting the endpoints to the histogram
endpoints.

The in-between values could be changed as a linear function between the two new
endpoints. In Photoshop there's a value which controls this function, but I'm
not sure how it works. It seems to use a power function taking values from 0 to
10 where "1" is linear, 1-10 sort of moves the pure red/green/blue to pixels
which previously were dark. 1-0 moves the palettes against the light area
making the whole image darker. Aw, I'm hopeless at explaining. I could post
some demo images if you're interested.

sig.

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