Sometime you may want to remove the white content or background from an image and fill it with another color. The quickest solution is to load the image in Photoshop, grab the Magic Wand tool from the toolbar on the left and click on the background you want to remove.
Then fill the selection with the color of your choice using the Fill Bucket tool or Paintbrush or Delete it to get a transparent background. But that doesn’t always work. Often you will find that around the edges some background pixels are left behind which makes the image look poor.
Here is an example. The image on the left is the original. The one on the right has the background removed using the Magic Wand and filled with blue. Notice that the shadow, which has a different shade, is not removed.
The second option you have is to use a combination of the Lasso tool to outline the image carefully. The advantage of using the Lasso tool is that you have full control on the shape of the selection. The downside is that the process is time consuming for complicated shapes and you still have to leave out the shadows if you want to fill it with another color.
Here the shadow of the apple had to be removed.
The third option is to add a colored layer below the image and change the Blending mode of the top layer (the image) to Multiply or Darken. You can do this by right clicking on the layer and choosing Blending option. Then Select “Multiple” or “Darken” under Blend Mode.
The result isn’t any good either.
The fourth option is to use the Kill White Photoshop Filter. This is a free Photoshop Filter that actively removes white from an image, perfectly leaving the rest of the image intact, whether the image is black-and-white or color. This is not simple masking. Pixels that are partly transparent are altered so as to only remove the white portion. Shadows and gradients remain in the image, only white is removed.
Lets run this filter on our image of the apple.
Perfect. Notice that the color of the apple is not changed and the blue background is visible through the transparent section of the glass apple.
Here is another example that demonstrates the utility of the Kill White filter. This is the original image.
The image when blended with a blue background yields this.
And this what we get by applying the Kill White filter.
Notice that the color of the skin is barely changed. Compare this with the previous image where the whole image gets a distinct blue tinge.
Kill White might not give desirable results every time you use it, as you can see there is a slight discoloration around the apple which would need to be removed. Checkout some of the other options you have got: