Many times when we take a photo or download a photo from the internet, its background is not to our liking. Usually, you will be disappointed and curse your luck for not knowing a powerful tool like Adobe Photoshop. But, don’t worry. You have GIMP.
GIMP, the free photo editing tool, is one of the best alternatives to Photoshop. It provides several ways to remove the image background by making it transparent. However, one of the most useful and easy methods (you’ll see why) involves the use of layer masks.
Before diving into the steps of using layer masks to remove the background, let’s have a quick understanding of layer masks.
What is a layer mask?
Layer masks are used in image editing to control the visibility of layers present below a layer. Normally, you would delete part of the image to reveal the layer underneath. But that’s what makes the layer mask so different. With them, you can hide or show some parts of an image without actually removing other parts from it. Think of it as a non-destructive way to remove parts of a photo from your view.
Still confused? Let me explain through a real example. You know how when you draw something, you use masking tape to cover up the places you don’t want to draw. That way, you can easily paint the surface without worrying about other areas. That’s exactly what the use of layer masks is in digital editing — you hide areas of an image using masks without erasing them.
Furthermore, layer masks make it easy to restore surfaces that you have accidentally deleted/hidden. That is not possible with other techniques where you have to go through the tedious undo and in some cases start from scratch.
Basic Layer Masks
Mostly, you’ll be working with two types of layer masks: white and black. When you add a layer mask, fill the surface with black to hide the parts and use white to show them. Remember it like this – black and white for the current layer.
White Mask (Full Opacity)
When you add a white layer mask, you won’t see any visual changes on your image (except for the layer mask in the layer box). To use it (or to remove the mask), you need to paint the picture black. When you do, the layer below your current layer will be visible. If there is no underlying layer, then transparency is exposed.
Painting the layer mask with black will make it completely transparent. To control the level of transparency, use other shades of gray. Use this mask when you only want to hide a small part of the layer, such as when removing the background of an image.
Black Mask (Full transparency)
Adding a black mask will make your entire image transparent. That is, your class will be empty. To show parts of your current layer (or to remove the mask), paint it with a white brush. That will make the pixels on the current layer visible to you. Black masks are useful when you want to hide most of the layer to reveal only a portion of it.
In short, when you have a white mask, use black to show the background, and when you have a black layer, use white to show the current layer.
Now that you know the basics of layer masks, let’s see how to remove backgrounds using them.
How to remove image background in GIMP
Step 1: Open the image in GIMP with the background you want to remove using the File > Open option.
Tip:
Step 2: Then in the layer box, right click on the image and select Add Layer Mask from the menu. Alternatively, go to Layer > Mask > Add Layer Mask in the top bar to add it.
Step 3: In the layer mask dialog box that appears, select the option White (full opacity).
You should see a small white box appear next to the thumbnail of your image in the layer box.
Step 4: Now that we have filled the layer mask with white, we need to use black to remove the background. For that, keep the foreground color black in the color box on the right.
Tips
Step 5: Click on the brush tool to activate it. Then color the areas that you want to remove. You’ll find that swiping the brush over the image removes that area. Apply strokes over the area that you want to make transparent.
Make sure that the mask is active when you start using the brush on your image. For that, just click on the mask in the layers panel. It should have a white border around it. If the image is selected instead of a mask and you start painting, you will see the usual black on your image.
Step 6: At any point, if you make a mistake while removing the background, you don’t need to start from scratch. Just invert the colors i.e. make the foreground color white and make the background black. Then draw on the area that you want to bring back.
Step 7: Finally, to maintain the transparency of the image, you need to save the image as a PNG file. PNG is different from JPG because it preserves the transparency layer. That is, if you save the image in JPG or any other format instead of PNG, the image will lose its transparency.
To save the image, click on the File option at the top and select Export As from it.
Tip: Use the keyboard shortcuts Shift + Ctrl + E (Windows) and Shift + Command + E (macOS) to open the export dialog.
Navigate to the folder where you want to save the image. Make sure to keep the file extension as PNG.
Get help from Layer Masks
Layef masks are not only useful in removing the background, but you can also use them for many other things. For starters, by making an image transparent, you can easily change the background of that image. Furthermore, you can apply effects to part of an image without affecting the entire image. Similarly, you can merge two images using them. Layer masks are also widely used for selective coloring.
Next up: Beautify your text in GIMP by adding a little drop shadow to it. Check out our detailed tutorial for adding shadows to text using GIMP.
Categories: How to
Source: thpttranhungdao.edu.vn/en/
