Tutorial (link): Edges, Outlines, Sketch effect

[DannyRaphael]

This is a terrific illustration of four easy methods for getting "edges" courtesy of Tammy Niemand. The final results can be used by themselves or as the basis for creating outlines for a watercolor painting ala the traditional method.

http://www.pbase.com/niemand/image/40579948/original

In the first example where she uses Smart Blur > Edge Only, another alternative is to apply Stylize > Diffuse > Anisotropic (to soften the edges a bit). Follow this with Edit > Fade, which allows you to control the degree of edge softening.

- - - - - - - - - -

To Tammy's excellent examples add:

(1) Find Edges:
* Duplicate Background
* Stylize > Find Edges
* Image > Adjustments > Desaturate
* Image > Adjustments > Levels (move middle slider to the left to get rid of some of the noise)
* Optional: Layer > New Layer Mask > Reveal all
* Below the sketch layer and above the original Background add a new layer and fill it with white.
* Click on the Find Edges layer mask and airbrush black to remove excess noise.
* Merge down when finished

(2) Glowing Edges: an alternative to Find Edges:
* After duplicating the Background, try Stylize > Glowing Edges instead. This filter allows you to have some control over edge characteristics.
* Image > Adjustments > Invert - To give you colored lines on white.
* The rest of the steps are the same starting with the Desaturate step above.

(3) Offset/Difference
* Background: Layer > Duplicate
* Background copy: Shift + Ctrl + U (Desaturate)
* Background copy: Layer > Duplicate
* Background copy 2: Change the layer blend mode from Normal to Difference, resulting in an all-black image
* Layer > New Adjustment Layer > Invert: Change to white
* Select the Move tool (press V)
* Click on Background copy 2: nudge the layer using the arrow keys until the desired degree of line detail is achieved. Usually a couple clicks down and a couple to the right will do it. It's a total judgment call.
* When satisfied create a new layer at the top of the layer stack.
* Alt + Layer > Merge visible to merge all layers into the top one.

~Danny~

[Flora]

Thanks for the link, Danny!!!

I don't usually go for anything 'artistic' but I'm quite partial to sketches!!!

[Joy_CA]

Hi Danny, thank you, for the link, I am very interested in sketches.

I have a question....
Do you know of a filter that would work in PSP and would emulate the PS Anisotropic filter ? I am using PSP9 and the program does not have the 'Anisotropic' filter. I have several tutorials that call for the Anisotropic filter, they just don't work well without that filter.

Joy

[Legacy~Art]

Most photoshop plugins work in psp, give it a try.

[Joy_CA]

I can't find a filter that is even close to doing what the Anisotropic does. I have run searches and nothing.....

Joy

[Stroker]

Joy, I might be able to help. I've got anistropic code.
I just have to finish ripping/converting it and compile it.
You should be able to use it.

However, things are really bad over here right about now.
Hopefully I'll have some time this weekend.
If I disappear longer than the weekend, send me a PM.

[Joy_CA]

Stroker, that would be the greatest thing since sliced bread....:-)

Thank you, thank you, ever so much.

Joy

[DannyRaphael]

Originally Posted by Joy_CA

Hi Danny, thank you, for the link, I am very interested in sketches.

I have a question....
Do you know of a filter that would work in PSP and would emulate the PS Anisotropic filter ? I am using PSP9 and the program does not have the 'Anisotropic' filter. I have several tutorials that call for the Anisotropic filter, they just don't work well without that filter.

Joy

Hi Joy:

You can get in the ballpark of the Anisotropic effect by applying some Gaussian Blur followed by some Unsharp Mask. It might take 1-3 applications, depending on the line characteristics and the GB & USM settings used.

[Stroker]

I was thinking this over while chasing the kids and trying to do the dishes. I think Displacement Sharpening by MV is the better route. I think it would be the more versatile route and save me the time of digging into various things.

Displacement sharpening is basically edge detection and then moving pixels towards those edges. Sometimes looks a lot like Smart Blur. Sometimes it works very well and sometimes it's poopy.

Now, MV has tossed in an option to View Edges and an anistropic kernel. Isn't that nice of him? Kudos, MV.

Two possible routes:
1. Let Displace Sharpen find your edges with Threshold and use View Edges.
2. Use another method to find edges, a little bit of blurring, then Displace Sharpen.

Not to mention having Displace Sharpen in your toolbox for other uses.

Not sure how well Displace Sharpen will work as a replacement for Diffuse > Anistropic, though. For regular anistropic edge work, should work more than dandy with the extra options.

Also, I have heard of a few issues of FM compiled plugs having some issues with PSP. If you can't use it, I'll do a little digging into this.

Let me know.
Here's to hoping.

[Joy_CA]

Stroker, FM works in my PSP I can't tell you how much I appreciate the help.

Not ever having used Anisotropy, I left the filter set at default. I will play with the settings. I am not sure what a before and after would look like, but I tried it and it made a big difference, it looks good to me

I have also been searching for 'Crystalize', any suggestions would be appreciated. PSP has Pixelate, but it just doesn't do the job. I downloaded a filter that was also called Pixelate, but has more settings, it does work better than the PSP filter, but, I'm sure it's not the same as Crystalize.

Danny, thank you for the suggestion, I will also give your idea a try.

Joy

[Stroker]

Glad it worked. I hate taking the easy way out, but I'm a little too strapped for serious coding.

I did some comparisons between Displace Sharp and Diffuse > Anistropic with regular photos. The closest I could get for a regular photo is:
Threshhold all the way over to the right.
All others to the left.
Not perfect, but awlfully close.

After a little more research, anistropic edge stuff is kind of interesting. Frustrating, but interesting. With more research and fiddling, I'm sure I can figure this out. Currently only working with the gradient and I think I need to implement magnitude.

Related, interesting stuff:
http://www.greyc.ensicaen.fr/~dtschu...tion/demo.html *very impressive
Canny Edge Detection

Crystalize is in the Worley cellular family. I understand the idea behind the algorithm, but I don't fully understand the exact mechanics of it just yet. You have build a list/array, find distances, modify the list/array, and a few other things. I'm working on it, but it's slow.

Back under my rock for awhile.

edit:
Oh! While the little one was helping me clean the microwave, the anistropic thing hit me right in the face.
I completely undertand it now. My problem was that I was thinking of terms of a single gradient derivative (I hate calculus, but it has it's uses).
Woohoo!
All I had to do was back up and think 2d.
Can't wait for this weekend.

[Joy_CA]

Stroker, thank you, I found the links very, very interesting.

PSP9 has a new filter called 'Digital Camera Noise Removal' (DCNR). It really works very well and has setting for small, medium and large noise removal. It also has the capability of protecting the part of the image that you do not want affected by the filter. I have found it very useful.

When I was searching for the Crystallize filter, I found the following explanations (but,no filter)....

Shows results...
http://www.rice.edu/Computer/Tutoria...p/stylize.html

"Crystallize
This filter achieves its effect by applying irregular solid-color shapes. The user-defined option of cell size specifies the size of the solid color shapes. This filter will make the image look as if the surface is covered with bumpy glass."

"The Crystallize Filter changes the image into a mass of polygonal shapes, making the image appear as if you are viewing it through a shower door. Clumps pixels into a solid color in a polygon shape. "

Thank you, for trying the settings, very helpful.

Joy

[Stroker]

Cellular in a nutshell
http://www.diku.dk/hjemmesider/studerende/duff/Fortune/

Worley's original code
http://www.texturingandmodeling.com/Worley.html

Fun Voronoi applet
http://www.cs.cornell.edu/Info/Peopl.../Delaunay.html

Uber cellular plug for A:M
http://www.ypoart.com/Downloads/Worley.htm

Getting a bit off-topic, eh?
Gotta go squish the kids.

edit:
Kids are mostly squished, but need some more squishing.
I'll be back later with one of my favorite edge techniques.

[Joy_CA]

Stroker, all of this is, waaaay over my head. I downloaded the Worley, but, I can't open it. It is a .TRB file (document ?), I have no idea what that is. When I click on it, I am ask what I want to open it with...duh. Too bad, it looked like it had real possibilities.

Joy

[Stroker]

Sorry, Joy. I should have clarified. That plug is for Animation Master. I included it just to show some of the things that can be done with a cellular procedural.

beep

[Joy_CA]

Stroker, no problem. I am having too much fun learning to use the one you gave me.

Thank you, for helping me.
Joy