On Wed, Oct 29, 2014 at 5:54 PM, Garyfx wrote:

I'm new to GIMP and need to create an effect from existing JPG images that look like a simple blueprint of the image objects. Specifically large trailers used for hauling race cars. The effect I'm after is not unlike the one on the background of the gimpusers website. Anyone know how to achieve this? I've attached an example of the effects here.

If I understood correctly, what you are after, you mighty have some luck with http://www.gimp.org/tutorials/Sketch_Effect/ as the first stage, followed by bringing the results of that tutorial to a background image filled with the blue color. Needless to say, you will probably have to remove background objects from your original JPEG files, so that they don't end up in the picture.

Alex

On 29/10/14 14:54, Garyfx wrote:

I'm new to GIMP and need to create an effect from existing JPG images that look like a simple blueprint of the image objects. Specifically large trailers used for hauling race cars. The effect I'm after is not unlike the one on the background of the gimpusers website. Anyone know how to achieve this? I've attached an example of the effects here. Thanks!

Attachments:
* http://www.gimpusers.com/system/attachments/163/original/Trailer_CADS.gif

You mean just exchanging colors?

You are looking for edge-detect. Fliters -> Edge Detect.

Play with the algorithms to get the one you like best. Try difference of Gaussians which might be best for what you want. After you detect the edges, you may have to use desaturate/invert/threshold also.

HTH, Partha

On Fri, Nov 7, 2014 at 3:34 PM, Garyfx wrote:

You mean just exchanging colors?

Well, I may have not been as articulate as I could have. I want to take JPG images of trailers and turn them into line schematics or outlines. I want just the line drawing or frame of the trailers like the images I attached in my original message.

And... a simple grey background is sufficient.

Thanks

-- Garyfx (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

On 11/07/2014 03:34 PM, Garyfx wrote:

You mean just exchanging colors?

Well, I may have not been as articulate as I could have. I want to take JPG images of trailers and turn them into line schematics or outlines. I want just the line drawing or frame of the trailers like the images I attached in my original message.

And... a simple grey background is sufficient.

Thanks

This PhotoShop-specific link explains how to use divide blend mode to make a line drawing; the technique is the same when using GIMP:

http://blog.advancedphotoshop.co.uk/tutorials/how-to-use-the-divide-and-subtract-blending-modes-in-photoshop-cs5/

Yes, that is the same as DOG (Difference of gaussian). :)

On Fri, Nov 7, 2014 at 3:56 PM, Elle Stone wrote:

On 11/07/2014 03:34 PM, Garyfx wrote:

You mean just exchanging colors?

Well, I may have not been as articulate as I could have. I want to take JPG
images of trailers and turn them into line schematics or outlines. I want just
the line drawing or frame of the trailers like the images I attached in my original message.

And... a simple grey background is sufficient.

Thanks

This PhotoShop-specific link explains how to use divide blend mode to make a line drawing; the technique is the same when using GIMP:

http://blog.advancedphotoshop.co.uk/tutorials/how-to-use-the-divide-and-subtract-blending-modes-in-photoshop-cs5/

_______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

On 11/07/2014 04:05 PM, Partha Bagchi wrote:

Yes, that is the same as DOG (Difference of gaussian). :)

Hmm, checking in GIMP 2.9 on a high bit depth image, I think the algorithms really are a bit different.

Checking in GIMP 2.8 on an 8-bit image, DOG gives much more useable results than "duplicate, divide, blur". I should have checked 2.8 results before mentioning "duplicate, divide, blur". It's a cool way to make a line drawing, but it doesn't seem to work very well at 8-bit precision.

For anyone using GIMP 2.9, the "duplicate, divide, blur" method gives more useable results if you first use the Levels lower left (output) Value slider to pull all the channel values well above (0,0,0). This is because the Divide blend mode gives odd results when zero is divided by zero, going to black instead of to white.

Best regards, Elle Stone

On Fri, Nov 7, 2014 at 3:56 PM, Elle Stone wrote:

On 11/07/2014 03:34 PM, Garyfx wrote:

You mean just exchanging colors?

Well, I may have not been as articulate as I could have. I want to take JPG
images of trailers and turn them into line schematics or outlines. I want just
the line drawing or frame of the trailers like the images I attached in my original message.

And... a simple grey background is sufficient.

Thanks

This PhotoShop-specific link explains how to use divide blend mode to make a line drawing; the technique is the same when using GIMP:

http://blog.advancedphotoshop.co.uk/tutorials/how-to-use-the-divide-and-subtract-blending-modes-in-photoshop-cs5/

_______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

_______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list