How can I take an image with a white background and make it transparent

8

0

I have a png image that has a white background. Is there anyway to take the white and make it transparent.

leora

Posted 2009-12-13T02:43:53.163

Reputation: 5 353

Answers

7

you can use Photofiltre (small, fast, free and portable):

  1. load the image

  2. go to Image > Transparent Color...

  3. choose the color (white), set the desired tolerance with the slider, click OK

  4. go to File > Save as... and save the image as .PNG

Molly7244

Posted 2009-12-13T02:43:53.163

Reputation:

10

The GIMP will allow you to convert a single colour to alpha, making it transparent.

The basic flow requires right-clicking on the image and choosing:

Filter > Color > Color to Alpha

And then selecting the white background. The GIMP will replace all white pixels in the image with transparent pixels.

Here's a good tutorial showing you how.

mlambie

Posted 2009-12-13T02:43:53.163

Reputation: 481

In newer versions of GIMP (I'm running 2.6), the Filter menu appears to have been removed. This option is under the top-level Color menu. – Bill the Lizard – 2017-02-22T16:19:25.247

6

I haven't seen a solution using Paint.NET here yet. It's an awesome lightweight image editor. To quote Jeff: "It raises the quality bar,"

  1. Download, install and run Paint.NET
  2. File > Open > Select your image
  3. Click the Magic Wand tool:

    Icon

  4. Click the white background on your image
  5. Press Delete
  6. File > Save

You can also select the tolerance of the magic wand tool before your use it to get rid of the "crust" or whatever you want to call it around your leftover image.

Travis

Posted 2009-12-13T02:43:53.163

Reputation: 2 125

The problem is the "crust" won't go away if there were lots of "border" pixels, i.e. gray diagonals that should've been half-transparent. – Dan M. – 2020-01-28T23:40:40.497

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You can use Paint.net to do this using the plugin Alpha Mask.

  1. Load the image. Select All (Ctrl-A) and Copy (Ctrl-C).
  2. Using the Effects menu, select Alpha Mask
  3. Leave the Mask File box blank and check the following options:
    • Invert Mask
    • Mix Alpha
    • Paste From Clipboard

After running the effect, you can optionally duplicate the layer and merge down to "darken" the image.

I know that Paint.net was used in a previous answer, but using the Magic Wand tool, or the Paint Bucket (to fill with transparency), will leave the edges of the image jagged. It won't look good on color backgrounds. Using the Alpha Mask method your image will look crisp on any background.

user2597747

Posted 2009-12-13T02:43:53.163

Reputation: 261

0

use GIMP... Select the white area and erase or delete it, you can select and use the DEL key, or use the eraser if that doesn't work as needed. Then save it as a PNG.

alpha1

Posted 2009-12-13T02:43:53.163

Reputation: 1 638

0

Photoshop (and Photoshop Elements) magic wand tool will allow you to select contiguous colours. You may want to play with the tolerance a bit... Once selected, hit delete to remove the white.

menns

Posted 2009-12-13T02:43:53.163

Reputation: 518