16 December 2012

Tech Tip– Transparency

by Leigh Lundin

Improve your Image

It amazes me how creativity bursts out of many of us in multiple ways, music, painting, sculpture, cooking, even quilting. Many of us like to include art in our blogs and find ourselves frustrated by cantankerous software. When it comes to clip art, you may have noticed some SleuthSayers pictures seem cursed with a white frame or background while others blend into the blog. For anyone with a non-white blog background, this is for you.

Once upon a time, little programs could make unwanted image parts invisible. Unfortunately, they've all but disappeared. I use Photoshop to set backgrounds to transparent, but that's using a steam shovel to shift a dustpan of dirt.

If you're interested (and this is by no means required) in how to do this, here are a few free tools you can use. Although I strive to be cross-platform, I've somewhat emphasized Windows here since Microsoft Paint doesn't support transparency and Mac tends to be more graphically inclined.
Gimp The Gimp MacOS Windows instructions
GimpShop GimpShop MacOS Windows instructions
Paint.dot.net Paint-dot-net
Windows instructions
LView LView Pro
Windows instructions

GIF and PNG

GIF and JPEG formats have very different purposes and you'll often see the wrong format used, especially JPEG. JPEG is intended for blends, subtle tones, and a large color palette such as photographs. GIF is designed for flat-tone images like line drawings, cartoons, and simple 'flat' pictures. There is a third format, PNG, which encompasses both images. To use transparency, you must use GIF or PNG, not JPEG although you can convert a JPEG to the other formats if it's tonally flat.

PowerPoint

Although I avoid PowerPoint, I understand it can be used to make parts of images transparent. Follow this video or these instructions:
  1. select menu: Insert Photo > Picture from File
  2. click Recolor button
  3. click Set Transparent Color
  4. click on the background color to disappear
  5. right click image
  6. click Save as Picture
  7. set Format to .PNG
  8. specify name and save
Here's to transparency!

7 comments:

Fran Rizer said...

Leigh, as you well know, I'm computer-challenged. This means that I appreciate your column today but it may not get rid of the white around my illustrations. After much thought, I've decided that, like in life and writing, it's point of view. When I frame a nice picture, I use a mat to enhance it. Please consider the white around my clips as mats to enhance their appeal.

Leigh Lundin said...

Matting it is, Fran!

Louis A. Willis said...

Thanks, Leigh for the information. I've been trying to use photoshop to set background to transparent for pictures I use in the newsletter I edit for my high school classmates. Unfortunately, photoshop and me don't get along too well.

I think I'll try the Gimp.

I also glad to know the difference between JPEG, GIF, and PNG. Maybe I'll try photoshop using GIF or PNG.

Leigh Lundin said...

Louis, Photoshop is not a simple program, but it has a took called Magic Eraser that can erase a background area. Just be sure to save your graphic as PNG.

Louis A. Willis said...

Thanks again!

A Broad Abroad said...

You're on the carpet for not revealing the secret of matting earlier! This pulled the rug out from under me.

Without piling on the agony, you've woven facts into an interesting yarn. I felt the underlying thread was information to dye for.

You ply your trade well. Borders on shear genius. A tuft act to follow:-)

Leigh Lundin said...

Ach! A luddite is PUNishing me.