I have a png image that has a white background. Is there anyway to take the white and make it transparent.
you can use Photofiltre (small, fast, free and portable):
load the image
go to Image > Transparent Color...
choose the color (white), set the desired tolerance with the slider, click OK
go to File > Save as... and save the image as .PNG
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.
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,"
- Download, install and run Paint.NET
- File > Open > Select your image
Click the Magic Wand tool:
- Click the white background on your image
- Press Delete
- 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.
- Load the image. Select All (Ctrl-A) and Copy (Ctrl-C).
- Using the Effects menu, select Alpha Mask
- 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.