Whitening Background
Date: Sun, 6 Mar 2016 06:54:17 +0100
From: forums@gimpusers.com
To: gimp-user-list@gnome.org
CC: notifications@gimpusers.com
Subject: [Gimp-user] Whitening Background
I am a beginner to Gimp and I hope this is a very easy question to answer.
I took a photo with my phone of a simple Blank & White label. I opened it in
Gimp and saved it as a .PNG file. What I need to do is brighten or whiten the
label background. When the picture is printed the White comes out greyish. I
need to whiten this greyish background so when I print the label it comes out
White.
I've tried everything I've learned in Gimp the past year but I simply cannot
figure this out. Any/All help would be greatfully appreciated.
Thank you!
This is actually a common, even expected, procedure to perform any time you're cleaning up an image taken from a scanner or camera. When you're initially taking the image, look around for any brightness/contrast/exposure related settings and use them because if you can get it right before capturing the image this will improve the quality of the end result even if you still need to make further adjustments to it in GIMP. Similarly, if your device has a highlight/shadows "alarm" function then switch that on to highlight any areas that are over/underexposed and washed out as either black or white. Normally washout is bad for a photograph, but in this case you're printing a label and you WANT the white areas of the source material to be washed out so the printer won't attempt to shade them in.
In GIMP's case, go to the Colors menu and pick either the "Levels" or "Curves" command -- the next steps vary depending on which tool you prefer but in either case you need to take the Highlight setting and brighten it until your white background tone washes out (becoming a solid RGB white).
- For the Levels tool, Highlight is shown directly in the dialog and corresponds to the arrow mark at the white end of the spectrum. Click and drag this mark to the left (into the light-gray area of the spectrum) to brighten the image.
- For the Curves tool, Highlight is the node at the top-right corner of the graph. Drag it to the left (keeping it aligned along the top edge) to brighten the image.
-- Stratadrake
strata_ranger@hotmail.com
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Numbers may not lie, but neither do they tell the whole truth.