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'Image filtering question'
2005\05\28@175141 by olin_piclist

face picon face
andrew kelley wrote:
> What sort of filter would I use to eliminate large areas of uniform
> color but keep smaller areas?

This question makes no sense.  Most image file format don't let you
eliminate pixels in arbitrary regions inside the image.  How would you
display such an image.  On a monitor each pixel is going to display *some*
color, and the same holds true for a paper print.


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2005\05\28@181257 by andrew kelley

picon face
Olin wrote:
> > What sort of filter would I use to eliminate large areas of uniform
> > color but keep smaller areas?
>
> This question makes no sense.  Most image file format don't let you
> eliminate pixels in arbitrary regions inside the image.  How would you
> display such an image.  On a monitor each pixel is going to display *some*
> color, and the same holds true for a paper print.

Yes, true, I did mean to change the color to a background color, not
eliminate the pixels; eliminate the colored area by replacing the the pixels
with a different color....

andrew

2005\05\28@193046 by Dave W Turner

picon face
Probably something like:

Look at a pixel.  If it's the colour you want to replace, i++, and put
the pixel's coordinates in a stack
Look at the next pixel.  If it's also the colour you want.... as above
If it's not, and i>10, replace all pixels in the stack with new
colour, i=0 and clear stack.

You can continue this, and it should replace any line of 10 or more
pixels with the colour.  Not sure how to make it work in 2d images.
Also, I don't have a clue in what format the image formats actually
store the pixels.

On 5/28/05, andrew kelley <spam_OUTleetslackerTakeThisOuTspamgmail.com> wrote:
{Quote hidden}

> -

2005\05\28@215851 by Josh

picon face
I think a 2d image would be just like your 1d explaination except you
have 2 pointers.

.....dave.w.turnerKILLspamspam@spam@gmail.com wrote:

{Quote hidden}

>>-

2005\05\29@062055 by William Chops Westfield

face picon face
>>>> What sort of filter would I use to eliminate large areas of uniform
>>>> color but keep smaller areas?
>>>>
Just to clarify, are you looking for an algorithm, or the name of one
of the commonly available "filters" (or "effects") in a high-level
program
like photoshop?

BillW

2005\05\29@204040 by andrew kelley

picon face
An algorithm would be nice.. But I think I found a way to do it..

use a filter like this (the laser scans horizantally)

float filtconsts[9]=
{-1/6,
-1/6,
-1/6,
.1/6,
2/3,
1/6,
-1/6,
-1/6,
-1/6};

multiplied by the vertical pixels.. So if you add all the
constants(uniform color), you get 0.  if you have a value near the
middle of the Y, the value falls through (> 0), if its a patch above
or below center, it comes out <= 0.

Or I'll train a NN to evaluate it so it will pass \ / - | patterns and
reject all others..

andrew

On 5/29/05, William Chops Westfield <.....westfwKILLspamspam.....mac.com> wrote:
> >>>> What sort of filter would I use to eliminate large areas of uniform
> >>>> color but keep smaller areas?
> >>>>
> Just to clarify, are you looking for an algorithm, or the name of one
> of the commonly available "filters" (or "effects") in a high-level
> program
> like photoshop?
>
> BillW
> --

2005\05\30@004332 by andrew kelley

picon face
Well, the filter kinda sorta worked.. It more functioned as an edge
detect on the areas instead of what I wanted... I'll try a ANN
tomorrow.. My wife Ashley just had a beautiful baby girl (Dakota Rose)
on 5/29 @ 1:57pm so I'm kinda tired out(and so is both of them)

--
andrew

On 5/29/05, andrew kelley <EraseMEleetslackerspam_OUTspamTakeThisOuTgmail.com> wrote:
{Quote hidden}

2005\05\30@081955 by Darrell Wyatt

picon face
Congratulations!
Is this your first?
D.

{Quote hidden}

>

2005\05\30@105937 by andrew kelley

picon face
On 5/30/05, Darrell Wyatt <RemoveMEn2gpinspamTakeThisOuThotmail.com> wrote:
> Congratulations!
> Is this your first?
> D.


Thanks! Yes it is. (and will be my only for a few more years til I graduate =P )

-
andrew

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