Exact center to prevent disc 'wobble'

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oatmeal769
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Exact center to prevent disc 'wobble'

Post by oatmeal769 »

Using GIMP
I'm having a hell of a time with some of my images and getting them EXACTLY centered. I check all my circles using zoom and ellipse, along with cross hair guides. When I save the image, everything seems as perfect as can be, but between then and the time they get to the site, they get rejected for not being perfectly centered. I'm primarily talking about the center hole, and rings. Sometimes though, the whole image wobbles. As near as I can tell, the error happens when I save the image somehow. Can anyone relate or point me in the right direction?
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akovia
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Re: Exact center to prevent disc 'wobble'

Post by akovia »

I don't do any cdart, but if you could post your xcf, I'd be happy to have a look. I'm certain we can figure out what's happening.
oatmeal769
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Re: Exact center to prevent disc 'wobble'

Post by oatmeal769 »

Here's a link.

https://www.dropbox.com/s/owohbzr513y2r ... submit.xcf

This is after I've saved everything, but before converting to .png. The error of which I speak exists here. I check and double check to be sure every ring is perfectly round and at dead center, but somewhere in the process of saving it, an error is introduced.
If you zoom in to exact center, you will see that I colored one pixel black. When I was working on centering everything, I made this dot exactly in the center of my cross hairs. You can see now however, that the dot is now in the upper left quad of where center is. My guess is that this has something to do with it.
I don't usually add a dot, I just included it this time to show my trouble.
Thanks!!
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akovia
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Re: Exact center to prevent disc 'wobble'

Post by akovia »

I think I see the problem. Raster images are comprised of pixels and you can't center something on a half a pixel. I re-sized the final image to 999px, auto-cropped the layer, then used the alignment tool to center it on the canvas.

Have a look and see if this is what you were after.

https://dl.dropboxusercontent.com/u/935 ... mit-r1.xcf

Let me know if it's still off and I'll have another look.
oatmeal769
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Re: Exact center to prevent disc 'wobble'

Post by oatmeal769 »

Yes, I think you nailed it... Unfortunately the background isn't transparent now, but I'm assuming I can still do everything like I was, except to "re-size the final image to 999px, auto-crop the layer, then use the alignment tool to center it on the canvas."
Would I resize the entire image - template and all - or just the cd label which has been dropped on it?

Thanks much!
oatmeal769
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Re: Exact center to prevent disc 'wobble'

Post by oatmeal769 »

Hmmm... Maybe I need a tutorial on doing what you just did. I can't seem to make the align tool do anything, and I'm still coming up with the pixel error.
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akovia
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Re: Exact center to prevent disc 'wobble'

Post by akovia »

oatmeal769
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Re: Exact center to prevent disc 'wobble'

Post by oatmeal769 »

Wow, very cool tutorial on the fly. I appreciate the excellent help!

So, resizing it to 999 will eliminate the centering issue. I was noticing that I had to make the whole image as an even number - not odd- to get it to fit into the template. I guess I need to do it with the entire image after it is dropped into the template too. I can't imagine others didn't have this problem using the template too?

You mentioned raster image vs. vector. Would it be possible / easier to simply change everything to vector? Or is that a can of worms I don't want to open?
oatmeal769
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Re: Exact center to prevent disc 'wobble'

Post by oatmeal769 »

In your video, if you look closely at when you rotate the image (cool trick BTW) you can see that the image is now centered, but the split-disc isn't - there's still wobble. BUT, I'm guessing that may be from when I saved the label the 1st time. I get the gist of what you've suggested though, I'll play with it.
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akovia
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Re: Exact center to prevent disc 'wobble'

Post by akovia »

Cool, I didn't catch that but it sounds like you have the tools now to do what's needed. Let me know if you get stuck.

Cheers

P.S. I missed your previous post. You wouldn't be able to convert that image to vector without great loss in quality. Vector is a totally different animal.

http://vector-conversions.com/vectorizi ... ector.html
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