How To Make Backgrounds Transparent
Removing the background from an image with GIMP is a handy technique when creating digital content from stock or free images. In fact, It’s necessary in many cases to make an image background transparent if re-using an object from an image. GIMP is a handy free background remover because there are multiple ways for GIMP to erase backgrounds. Plus GIMP works on Windows, Mac or Linux which makes GIMP a great option. Since GIMP is free, that means there are no subscription fees, and you can continue to work even if you’re not online.
While removing backgrounds from images with GIMP depends on image complexity, there are 5 basic ways that GIMP makes backgrounds transparent. GIMP erases backgrounds with four tools or using layer masks.
GIMP BACKGROUND REMOVAL TECHNIQUES
Let’s look closer at how to remove white backgrounds, make transparent backgrounds and even create logos and pictures without a background . I’ve added short 1-3 minute videos to demonstrate ( I like short videos and think you’ll get this immediately!)
Magic Wand Tool (aka Fuzzy Select)
Free Select Tool
Layer Masks Method
Each technique to make the background transparent by removing it is specific to different types of images.
Example 1. GIMP White Background Removal With Color Tool
The Color Tool is the simplest choice; it’s a straightforward process if using GIMP to remove white backgrounds or to remove uniform color backgrounds. The color tool selects on regions of similar color.
Colors including both white and black have a 6 digit number that represents that color in the digital or electronic world. White is ffffff and black is 000000. Each color is unique. So a “solid” background is represented by just one color or one 6 digit number. GIMP’s Color Tool can easy selected large solid areas (white or color) by their unique 6 digit number (it’s actually called a “hexadecimal code or hex code” for short.
Click or selecting an area selects the color of the pixel clicked on, and GIMP then automatically selects all other pixels of the same color code (hex code). So the GIMP color tool works best with uniform background colors. If the shades of color in the background are present then holding down the shift key and continuing to make addition selections will pick up the multiple colors or shades.
But in this example, the color tool makes a transparent background very quickly. As shown below, the Color Tool is perfect for having GIMP remove white backgrounds of images, icons or illustrations.
Here’s a simple image from Pixabay to demonstrate how GIMP is used to “cut out” the background. This works with icons and illustrations as well because the differences between the image to keep and the background to be removed are clearly defined. The result is used in pdfs, webpages or designs.
You will need to add an alpha channel prior to removal of the background. Simply go to Layers>Transparency>Add Alpha Channel. Next select the color tool and click on the white area of the back. Hit the delete key and you’re done.
Here’s the result.
White background removal result.
Example 2. GIMP Remove Background Color With Magic Wand (Fuzzy Select)
The Magic Wand is similar to the Color Tool; it works best when the background is a very different color than the image you wish to keep. The Magic Wand or Fuzzy Select works like the Color Tool and in cases where the background image has a lot of shades or color gradients in the background that do not exist in the image to be retained. That last part is important because there is no way to refine how the Magic Wand selects areas to be removed.
Shaded color background removal – before
Which is why I find Pixlr Editor Magic Wand easier for this type of background removal (but that demo is for another article). The GIMP Color tool simply doesn’t have the fine tuning “tolerance range” for color selection that Pixlr has. Still for simple shaded areas that do not have those colors in the remaining portion of the image the GIMP Magic Tool will work quickly and efficiently.
To use the color tool, select the background color. Hold shift and select (click on) additional shades of color within the background area to add to the selection for removal. Pressing the Delete key or using Edit>Clear will delete the background.
FYI. Hovering over the Magic Tool shows a brief description “selecting continuous regions based on color”. GIMP documentation says this about the Magic Tool:
“…tool is designed to select areas of the current layer or image based on color similarity. When using this tool, it is very important to pick the right starting point.”
That last bit does matter; you may need to test where to start and how to select additional shaded areas to get the cleanest result for removing the image background.
So as an example here’s a simple image with a shaded blue area. Remember to add the alpha channel prior to attempting to delete.
Here’s the result.
after background removal
See the video
Example 3. GIMP Delete Background By Image Selection (Free Select)
Using GIMPs free select tool to remove backgrounds is a different way to accomplish the task. It works very well to “draw” around an object in an image but in this case, copying the selection and pasting to a new transparent file or layer effectively removes the background. It does require using the Color tool to remove the white default background of the new layer or file.
The Free Select Tool works in situations where it’s easier to outline what to save rather than trying to select everything to remove. In cases where part of the image is the same color or similar to the background, this tool allows defining what should remain. It takes a bit patience and will require zooming into the area to clearly see what to select but it is handy for certain situations.
To show how this works, here is an image of some balloons, I’m only going to save one to keep it simple. Simple Zoom in (I used 400%) to the ballon on the right. Then with the Free Select tool click on the edge of the ballon and continue until it is completely outlined. Double-click in the middle.
Before background removal with GIMP’s Lasso Tool “Free Select Tool”
Now, I’ll “lasso” the upper right ballon, copy it. One option is to save to a new transparent file. I could also just right click use Select > From Path than Select > Invert. Since I “lasso”d the object to be saved if I hit delete I would delete the ballon rather than the background. By inverting what I “lasso’d” the background gets selected before I hit delete.
GIMP’s Free Select Tool selects what you want to save rather than what should be removed.
Check out the video.
Example 4. GIMP Transparent Background Using Paths Tool.
The Paths Tool is similar to the Free Select or lasso; the difference is that the Paths Tool allows for fine tuning the selected object by moving the Path nodes to make curved path lines of selection. It produces a clean result from complex images with very defined objects. The Paths Tool works by placing lines or curves attached to nodes around the area to keep. After creating a rough selection, you can refine the selection of the background to remove using by dragging the lines and curves in between the node points. Hit Delete when you’re done. I’m going to use the same image as previous but use the Paths Tool to save the middle ballon. I’ll still zoom in a bit to use the tool.
I’ll skip the before as it’s shown above. but here’s the result after image background removal.
Using GIMP’s Path Tool to remove a background
Check out the quick video
Example 5. GIMP Layer Mask Background Removal.
While Layer Masks aren’t really a GIMP “tool” this technique works well on images with areas that are hard to lasso or outline. The strategy is to use Layer Masks to create a copy of the image in black and white; that copy defines the transparent area of the image. It’s is the most complicated way for image background removal, takes the most time and requires the most steps to accomplish. If the goal is to cleanly remove the background this method is best with light colored background (think white).
It’s also a great technique to use when making a photo collage where images overlap and fade into each other. But that’s for another demo.
So here’s an image of a cute bulldog. The lace on the pillow would be hard to separate from the background however it is possible with a mask.
The steps involve creating as much of a contrast as possible by using 3 color menu options (Color> Hue Saturation, Color> Levels, Color> Desaturate). Then with duplicate layers and a layer mask the background is removed. Two copies of the original are made with the original set to invisible. The second copy is modified to set the Hue-Saturation to 100 and then use the Color>Level to pick the darkest “white” of the background (the part under the pillow). That resets the white background to a more uniform white. Re-setting the Hue-Saturation again to 100 and then
Here’s the original image.
Before using GIMP Layer Mask as a way to remove the background.
Here’s the result shown in GIMP just to show that the background is now transparent.
Check out the 3 minute video for details.
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