Post Reply 

Image cropping tips

Apr 27, 2012, 17:48 (This post was last modified: Apr 27, 2012 17:50 by STU9000.)
Post: #1
Image cropping tips
The colour selector tool is quite handy and fast for selecting regions rounds objects in images that you would like to edit into another file, however it tends only to work effectively where there is a marked colour contrast between the object and the surroundings.

Sometimes the only way to cut that object out is to go round it manually with the free select tool which can of course be quite a laborious task.

So I just wondered if anyone had any interesting tips for doing this?

One technique I have discovered, which sometimes works quite well is to quickly select round the object with the free select tool leaving a smallspace. Invert the selection and perform a Gaussian blur, then use the colour select tool. I have found that this helps the software to select more of the appropriate region you want to clear, and then if there are any bits left you just go round it and rub them out with the rubber tool.

It doesn't always work, but sometimes it can save you a bit of time.

Another way could be to select regions of the image and perform a colour select on that specific region, thus possibly avoiding the software inadvertently selecting parts of the object that you don't want to clear. I'm not sure how to do that though without cropping the image down. Of course if that happens you can always cut and paste a rough cut out of the objects inner region and copy and paste into a new layer and merge.
Find all posts by this user
Quote this message in a reply
Apr 27, 2012, 19:27 (This post was last modified: Apr 27, 2012 19:28 by ofnuts.)
Post: #2
RE: Image cropping tips
(Apr 27, 2012 17:48)STU9001 Wrote:  The colour selector tool is quite handy and fast for selecting regions rounds objects in images that you would like to edit into another file, however it tends only to work effectively where there is a marked color contrast between the object and the surroundings.

Sometimes the only way to cut that object out is to go round it manually with the free select tool which can of course be quite a laborious task.

So I just wondered if anyone had any interesting tips for doing this?

One technique I have discovered, which sometimes works quite well is to quickly select round the object with the free select tool leaving a smallspace. Invert the selection and perform a Gaussian blur, then use the colour select tool. I have found that this helps the software to select more of the appropriate region you want to clear, and then if there are any bits left you just go round it and rub them out with the rubber tool.

It doesn't always work, but sometimes it can save you a bit of time.

Another way could be to select regions of the image and perform a colour select on that specific region, thus possibly avoiding the software inadvertently selecting parts of the object that you don't want to clear. I'm not sure how to do that though without cropping the image down. Of course if that happens you can always cut and paste a rough cut out of the objects inner region and copy and paste into a new layer and merge.
See here for the dangers of the Color selector and the Magic Wand.

For "natural" objects, you can use the Paths tool to make a path around the object, and then get a selection from the path, or use the Scissors. You can combine the various techniques (and have a coffee break without losing your work) as explained here. You can also make selections using combinations of the color channels (useful for some very complex shapes such as loose hairs).

In some cases the best technique is to duplicate the layer and erase all the object surroundings, coarsely at first , and then finishing using a soft brush (using a layer mask for this instead of a plain eraser gives better results, and using a tablet instead of a mouse also vastly improve things).

Now answering your questions on
https://Gimp-Forum.net
Visit this user's website Find all posts by this user
Quote this message in a reply
Apr 29, 2012, 15:06
Post: #3
RE: Image cropping tips
Cheers ofnuts, will have a look at those links..
Find all posts by this user
Quote this message in a reply
Post Reply 


Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Image Map - update existing image w/links Norkuvich 1 147 Sep 18, 2017 08:16
Last Post: paynekj
  How to remove shaky camera ghost image? ianpwilliams 4 1,506 Aug 12, 2017 13:47
Last Post: Elizabeeth
  How to extend an Image from side to side softening the hard edge of image Flesh 2 214 Jul 21, 2017 06:21
Last Post: Flesh
  Image Quality Degradation Issue dedoubleu 2 291 Jun 7, 2017 06:37
Last Post: ythgilb
  Losing image quality Futant 2 282 Oct 10, 2014 16:07
Last Post: rich2005

Forum Jump:


GIMP ForumPortalArchiveContactTermsRSS