HowTo: Add artificial print bleed area to images
For our album "X marks the spot", I've encountered the problem that some images did not really have a lot of content free "space" around their edges. Unfortunately, this causes details to be cut off during printing, because it's necessary to have a so called "bleeds" to avoid white areas at the edge of the paper.
This tutorial explains a nice workaround to this problem...
Since I couldn't simply go out and re-make the affected photos, I've found a way to add a virtual bleed border around the image using simple graphic editing methods. In the tutorial, I'll explain how the principle works, but for all lazy ones of you (like me), I've written a GIMP plugin in Python-Fu, called "cheap print bleed".
Here's an example of the applied effect:
The general principle is quite simple:
- Resize the image canvas to whatever size you finally need
- Copy the original image layer
- Resize the layer copy to be exactly 2 pixels higher/wider than before
- Lower the layer copy
- Repeat steps 2-4 until the whole area is filled
- Merge visible layers
Easy, but it sucks to do it manually - especially for high resolutions where you need to fill e.g. 100 (!) pixels on each side.
Using the plugin
First of all, download and extract the "cheap print bleed plugin" plugin to GIMP's plugin folder.
This can be per-user (e.g. "~/.gimp-2.6/plug-ins/") or system-wide (e.g. "/usr/lib/gimp-2.6/plug-ins/").
Of course, adapt GIMP's version number accordingly.
If you did it correctly, you should see a new menu item in GIMP's "Image" menu, called "Cheap print bleed". If the item is there, proceed:
- Open the image in GIMP
- Select the whole image: Select > All (Strg+A)
- Add a border to the selection: Select > Border > 2 pixels
(NO feather border / NO lock selection to image edges)
- Copy/paste this selection to a new layer
- Turn all layers except this new one invisible
- Apply the "cheap print bleed" effect: Image > Cheap print bleed
It might be necessary to run "Image > Autocrop image" after applying the bleed effect, due to transparent pixel leftovers.
Here are 2 examples with their original version - and after adding a virtual print bleed:
|As you can see in the first example, the heads of the two people in the background would have been cut off without the bleed area.|
|In the second image, the corpus of the violin would also have been cut off in the original.|