Removing backgrounds from images is a great way to combine pictures. Then you can place the foreground of one image, or just one thing in it, over the background of another. There are a couple of ways to do that with the freeware Paint.NET, which you can add to Windows 7, 8 and 10 from here. Paint.NET’s Magic Wand tool is essential for both methods.
Remove the Background with the Magic Wand and Eraser
First, remove a background with the Magic Wand option and Eraser. Click File > Open and select an image to erase the backdrop from. Then click Tools, and select the Magic Wand option. Your cursor should become a Magic Wand selector as below.
Now click an area of the image background to remove with the Magic Wand selector. It highlights the area and colors it will remove as shown below and turn transparent. If the selector also includes some areas of the foreground that you intend to retain in the image, drag the tolerance bar further to the left. This effectively configures the tool to select fewer color shades. Dragging the bar more to the right will increase the number of color shades selected, so will most probably include some areas of the foreground if above 75%.
Then press the Del key to erase the selected area of the background. Keep on selecting areas of the background to erase with the Magic Wand tool, and press the Del key until you’ve removed most of the background as shown in the snapshot below. To erase smaller areas, press Ctrl and + to zoom in and select them.
Now you might be left with a few small specs of colors scattered in the background. You can use the Eraser tool to remove left over backdrop colors. Click Tools > Eraser and then hold the left mouse button and move the cursor over the remaining background colors to remove them. Select a higher brush width to wipe the remaining color gradients off the background more quickly, which could then leave you with output comparable to that shown directly below.
In the shot above, I’ve removed all background sky line from the picture, turning it transparent. Now you can fill the empty background with another picture or whatever color you’d like. Select Layers > Import From File and open another image to combine it with. Press F7 to open the Layers window shown in the snapshot directly below.
The image you just opened will be at the top of the stack. You need to move it below the one that includes the foreground to make it the background picture. So select it on the Layers window above and click Move Layer Down (the down arrow button). Then it will replace the backdrop of the foreground picture as shown below.
Remove the Background with Magic Wand and Paintbrush Tool
So that can be a good way to remove backgrounds from images. However, it might not always be entirely effective if the foreground and backdrop have similar colors. Then the Magic Wand might also erase areas of the foreground to retain. If that’s the case, or you only need to keep a small amount of foreground in an image, it might be better to combine the Magic Wand option with Paintbrush or Line/Curve instead.
First, open the image you’re going to remove the background from. Then set up another layer on top of that. So select Layers > Add New Layers, and press F7 to check that they are stacked as shown directly below. The empty layer should be on top of the background one.
Select Tool > Paintbrush, and choose a small value from the Brush width drop-down menu on toolbar. Now trace around a foreground object or other detail that you intend to keep in the picture with the Paintbrush tool. Trace around the object’s perimeter cleanly, and make sure there are no gaps left in the outline.
If the object has lots of straight lines, the Paintbrush tool might not be ideal. The Line/Curve option could be a better alternative. That enables you to draw out straight lines. Select Tools > Line/Curve, and drag a straight line along the edge of the object and press Enter. Then drag more lines around the foreground object’s perimeter and connect them together without any gaps.
Now click the Magic Wand option, and select inside the foreground object’s border. The border selection should then be highlighted. Press Ctrl + I to invert it.
Next, select the background image layer and press the Del key. Alternatively, you can also click the Cut button on Paint.NET’s toolbar. That will then remove all the background around the object’s border you traced out with the Line/Curve or Paintbrush tools as shown in the shot below.
The foreground will still include the border you traced out. To erase that, select the top layer on the Layers window. Then press the X button to delete the layer. Now save the image by selecting File > Save.
Now you can add a new background to the foreground detail. Open a new background image by selecting File > Open, and then click Layers > Import From File. Select the image you removed the background from as the new layer. Then the foreground object will overlap the background as below.
You can move the foreground object to new positions by selecting the top layer. Then click Tools > Move Selected Pixels. Left-click and hold the mouse button to drag it around the background image with cursor. Resize it by dragging the corners of the rectangular border around it.
The disadvantage of the Paintbrush method to removing backgrounds is that it’s not always easy to trace foreground details entirely smoothly. However, you can smooth out the tracing with additional options such as the Feather tool, which is a part of the BoltBait’s Plugin Pack. Click BoltBaitPack41.zip on this page to save its Zip, which should then be extracted to Paint.NET’s Effects folder. Then click Effects > Object menu > Feather to open the tool.
Alternatively, if some of the background is still around the edges of the foreground you could always use the Eraser tool to remove it. Select the foreground image on Layers window to edit it. Then zoom in with the Ctrl and + hotkey, select Eraser and brush over background to remove it.
So that’s how you can get rid of image backgrounds. Then you can add entirely new backdrops by combining them with other picture layers. Removing backgrounds with the Magic Wand option can transform your photos.