How To Cut Out Part Of an Image Using Affinity Photo

Hi, this is Gary with MacMost.com. Today let's look at using Affinity Photo to cutout part of an image.

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So many times in the past I've shown you how to cutout part of an image in a graphics app. I think Affinity Photo seems to be the popular choice now as a Photo Shop replacement on the Mac so let's look at how to do it using Affinity. I'm going to drag and drop an image from the Finder into Affinity Photo. There you could see there's me and a background. Let's cut me out of this and then do things to manipulate me and the background separately. Also just paste me into a different image.

The basic idea is to select just me and not any part of the background. You have several tools for dealing with this in Affinity Photo. First let's go use the Brush Selection tool right here. I'm going to take that and I'm going to use it to select the subject as best I can. Now up at the top here I've got a width button. So notice the circle here is a certain size. I can change that size and make it smaller or larger using this control. I could also use the square bracket keys on the keyboard to do it. So I can start selecting me by just clicking and dragging. You could see how it's going to grab some of the selection. We don't have to worry about it being perfect now because we're going to learn how to refine this in several different ways.

Let's first just start by grabbing the general area that we want. You could see it does a pretty good job. How good a job it does really depends on how well the subject stands out from the background. So now we've selected a lot of things here. Let's refine it first by continuing to stick with the brush selection tool. I'm going to use Command and Plus to zoom in. You could also do it with your trackpad. Now I could just move around here inside of the image and look for places where things aren't perfect.  So let's go and shrink down the width of the brush selection tool here so I have something much smaller. Now I can click and select more of an area here. I can fill in some of the spaces that it missed.

In some cases maybe it grabbed a little too much. Let's do say this and say oops it grabbed a little too much there. I can hold the Option key down and then I click and it's going to subtract. You can do the same things by switching modes between Add and Subtract. But holding the Option key works faster. So let me go over here and further refine this area. I could keep adjusting the size for what I need and see how well I can do here. Grabbing pieces that I may have missed when I was zoomed out a lot more.

So once we've done a little work adding and subtracting areas we can go to the Refine Tool. Click this Refine button here and it opens up a separate set of controls. Now notice how everything that we haven't selected is red and everything we have selected is its regular color. You can change that here using Preview. So that's the overlay preview. I can go to Black matte or White matte to just make everything I haven't selected a solid color like that. I could go to black and white like that and I can go to Transparent just making everything I haven't selected transparent there. So you're going to switch between these because they each work better in different situations.

Now you have several settings for the Adjustment brush. You have Matte, Foreground, and Background. Matte will try to make things a little bit better if you select the area. So you can see here the selection isn't so good. Let's zoom in a little bit and go right here and I could click and drag this area and when I release it will attempt to do a better job of selecting what's there. So you could use this to further refine things. Now if I switch the preview I get a better sense of what's selected. If I switch to background I can make something specifically part of the background. So I can kind of erase this. Maybe get rid of some of the extra stuff right here.

Let's go back to Matte and you could also adjust things like the border width. When you do that it's going to increase the width of the border there to reassess the Matte and grab more or less. You can always use Command Z to Undo things while you're playing with them here. You can also adjust the Smoothness and it will adjust things a little bit. The Feather. Different adjustments work in different ways. It really depends on the image how well it's cutout from the background and foreground. How many things like hair or fur or smooth edges are in the cutout. 

So you're just going to keep playing with this. Maybe I'll use the background tool here to get rid of a little extra. Things like that. Go to the Matte tool here and attempt to make this a little bit better. Sometimes it works and sometimes it doesn't. You really have to play with it. There's a reason why you have these tools here and you have to use them manually is because you constantly have to keep making adjustments. I'm going to use the matte tool here and you could see it does a pretty good job in that specific case.

Now, let's zoom back out and look at what we've got. So it looks pretty good. We can look at it in overlay here like that. We can look at it as a transparent image there. When we're satisfied with it we can choose what we want to do with it. Now we could just go and hit Apply and just have this area selected. We could do things with it like Copy and Paste. But we could also select to create a new layer. Let's do that. I'll do New Layer and hit Apply. So now we can go here and look at the layers. We can see we have two layers. The layer that we just cutout and the background. I can make the background visible again and now we'll see both. The thing I like about this is if I make the cutout area invisible you could see the background still includes the subject. So it's just basically overlaying one on top of the other. 

Now we could do really cool things with it. For instance with this selected I could click up here to Develop Persona and it will change the tools here and here just for changing the photographic settings of that layer. So for instance I could increase the exposure of just that layer and you could see it's just that and not the background. So we could hit Develop here to Accept those or Cancel. We could also add filters. So in this case instead of having it filter to the subject I'll go to the background here. I'll go to Filters and Blur and I could just blur the background. I could hit Apply and now the background is blurred.

Let's Undo that and instead I could add an adjustment layer. Click here and let's add an adjustment layer for say the exposure. I'll adjust the exposure. I can change the exposure, say, for the background like that. If I go into Layers I'll see that the exposure layer is between the subject and the background. I can move up and have it applied to both. Or I can drag it into a layer and have it applied to one layer or the other. 

So now what if I just wanted to take this subject and place it in another image. So I can select the layer here. I can simply copy it and let's open up another image here. Just drag and drop to Affinity Photo the second image. So I have two tabs open. This one and this one. I can simply paste this layer in and there it is. Let me switch to the Arrow tool and I could move it here. I could shrink it or enlarge it. I can, of course, add those effects and adjustments to make it fit in a little bit better here. So it may make sense to add an adjustment layer for exposure here. You know increase the exposure of just the subject. So I'm going to go into layers here and move it underneath this layer here so now this is a little brighter. Work on that a little bit to get it to look a little bit more natural in this setting.

Now once I have things like I want I can go ahead and File, Export and export this out as a new jpeg image to share. Let me show you just one more example. I'm going to take a piece of stock photography and you could see here this is a bear on a white background. I would be nice if that's transparent. Maybe I could use it in Keynote over a gradient background or something like that. So I could do the same thing here. I could use the Brush tool. Let's enlarge the circle quite a bit. I'm going to select the bear. I'm going to refine the area a little bit more. Go to Refine. Let's zoom in a bit. Now I could use the Matte tool here and it will actually do a really good job because the background is so different than the foreground. So you could see I select this portion here and how much better it gets. The same thing here. 

Now I'll change this to a Mask here. What a mask will do is it will keep the same layer but it will apply a mask to the subject so that the rest of it isn't visible anymore. So it makes the background invisible. Then I could go to Layer, New Fill Layer and there's a color here. I could click on that and I can use one of the color tools here and choose a new color for that. Let's move it behind the bear and now you could see here the bear on any color that you want. Or I could simply Copy this layer here and paste it here as a new layer here on this image.