Smooth coasts & Style?

[Midgardsormr]

The "pixellizing" effect you're seeing is called aliasing. It is an artifact of using a digital medium—you cannot get a truly smooth angled or curved line when the image is built of discrete pixels that are either "on" or "off." The solution is to use some intermediate shades in places along the boundaries to create the illusion of smoothness. This is called anti-aliasing. For reference, I posted some example images a while ago here: http://www.cartographersguild.com/sh...ll=1#post14957

Most of the time, you want to start with anti-aliased lines because there's not really any easy way to reliably and accurately anti-alias them later. To that end, avoid using the Pencil tool, and be careful not to threshold things too harshly. Also, work at a resolution high enough that you are not relying on pixel or subpixel accuracy for your detail.

Now, if you really need to fake antialiasing, there are a number of approaches you can use. Personally, I like to use some resizing tricks. In the Preferences > General menu, set Image Interpolation to Bicubic Smoother. Enlarge your image to 200% in both directions. Give it a 1 pixel Gaussian blur. Go back to the Preferences and set Image Interpolation to Bicubic Smoother. Reduce your image to 50% in each direction (returning it to the original size). The lines should be somewhat smoother. Try it with and without the blur step, try different combinations of the interpolation algorithms (except nearest neighbor—that one will actually enhance the aliasing instead of reducing it), and see if going to 400% or 800% and back down does anything more for you. Different sizes of blur will give you different results, too.

This is not truly antialising, though, as it softens the lines rather than blending them properly. You could also try some tricks with layer effects. A 1-pixel stroke or even a very small outer glow might do the trick for some shapes and styles.

Here's a sample of what I did while I was experimenting. In the upper left is my original, aliased shape. In the top center, I simply increased the size by 200% then reduced it by 50% with Bicubic interpolation both directions. Top right, I did the same thing with a 1-pixel Gaussian blur. Bottom left, I used the resizing process I described above. Bottom center has an outer glow set to Blend Mode: Multiply, 65% opacity, Color: Black, Technique: Softer, 0% spread, 1 px size, and a linear contour.

[Alex]

@Schwarzkreuz:

I apologize Schwarzkreuz, but I am having a difficulty understanding what you mean. You selected it with the wand, right? How did you smooth out the layer if it was blank? Or was there something you added on the new layer?

@Sular:

Thank you very much for the images and explanation, Sular! I was just about to say that the wand forcefully grabs parts I don't want to, but I'll keep trying to get it right. I like the image's coast/lines in the left picture you uploaded as well. I'll try the option out now.

@Midgardsormr:

I see! Thank you very much for the link and post, Midgardsormr. I did not know about "anti-aliased lines". Also, nice post with the descriptions as well, very useful (especially for my spriting!)! *rep* I will try this option as well!

Once I finish each version, I'll try and upload them so I can show them off (in case I'm being stupid xD)! Oh, and I'm going to rep you all too! Promise. (:

*Schwarzkreuz, it says I cannot rep you yet. I will when I spread. :>*

[Alex]

Sorry for the double post, just reporting back.

I tried each of the methods, but none of them made it smoother. I tried increasing and decreasing from 800 and 900 as well with the blurs and even tried increasing the blurs, but the terrible pixelized look was still there. Blurring it erased some of the coasts and all of the islands. The magic wand too method's coast lines ended up being the same as well.

So I tried Paint SAI Tool to recreate my landmasses. I was wondering if the lines looked smooth, or if it didn't work right:

Besides the above, I have tried everything I could think of, even redoing the tutorial with a new map. Same old pixelized coasts.

[Sular]

Hrm, that is somewhat strange. I did try playing around with my tutorial images to see if I could create a jagged coast. I did manage it by selecting the interior of my linework rather than the outside and then reversing the selection. Even after smoothing the interior-selection version was more jagged than the other. So, clearly, the way one selects things matters.

One thing that occurs to me is that the image resolution might well be a factor. I have mine set at 300 pixels per inch.

[Alex]

Oh man, that would be a shame if it was the problem. I would have to find a way to recreate the map with a higher reso. How can I check the current resolution of my image? (assuming that is what you mean?)

[Sular]

In PS it is listed under "Image Size" as resolution. You can adjust the resolution in the text box to whatever you want it to be.

[Alex]

If 300 is recommended as the minimum, then I definitely believe its the problem. The image's size is 1990x4212, with a reso of 72!

If I changed the reso in the image, would it work, or would I have to restart? And if so, is there away way to preserve what I have now...? I would hate to have to lose what I have now.

[Sular]

If you alter the resolution it will likely resize your image again, which might help. That said, 1990x4212 is not a small image at all. Would it be possible for me to see what you've got and to play around with it? I may be forgetting a step or something and having a sample to work with may help me figure this out.

[Alex]

I changed the reso to 300, and it increased the image. It helps a bit, but much of it was sorta changed and still a lot pixelized.

Sure thing, I do not mind. The PSD file right, right?

[Sular]

If you can, sure. If that is too large, then just the coastal outlines should be helpful.