Cutting Out Leaves Mess Around Image

[TomHu]

Hi, I'm new here and to Affinity Photo!

My first time cutting out a person from the background didn't go so great. I made the background disappear by using a mask. But when I turn the mask off, I see this mess all around the edges of the person I cut out... 

Why is this happening, is this a bug or am I doing something wrong? I followed this tutorial on Affinity's Vimeo page: https://vimeo.com/channels/affinityphoto/134729670

I'm using an iMac 27 (Late 2012) running macOS Mojave. 

 

[toltec]

Was, Matte edges unticked in Refine Selection? If you refined the selection.

That can sometimes produce similar results on lower resolution images.

[TomHu]

11 hours ago, toltec said:

Was, Matte edges unticked in Refine Selection?

No, "Matte edges" was checked. The image is higher resolution as well. I tried another image yesterday and got the exact same results. This is kind of a big problem for me because I do a lot of this kind of photo work. 

[firstdefence]

How are you making this mask?

The way I would generally do this is... 

1. Choose a fair sized width for the Selection Brush, I worked on approx 1700 x1900px image and made the selection tool brush size 80px, choosing too large a brush can result in what you are experiencing. 
2. Select the background area to delete  as well as you can.
3. Now press <Q> on the keyboard to enter Quick mask.
4. Using the Paint Brush Tool <B>  refine the edge selection, by flipping between black and white using the <X> key (Black adds to the mask, White removes the mask)
5. Once you have a selection you like press <Q> again to come out of quick mask.

You should be able to delete the background cleanly and place your background behind.

saved with history: replace background.afphoto

[TomHu]

I followed this tutorial I found on the Affinity Photo Vimeo page, and did it pretty much exactly like this: 

I use the selection brush tool first as well, then use the Refine option to go around the edge to make the selection more accurate and clean it up as much as I can. Although I'm finding Refine very sloppy, see this post from today for more details: 

Your method sounds fairly manual, which I'm not adverse to, I've been doing this for many years in Photoshop. But it would take me so much longer to cut out images the way you describe, especially for some of the photos I work on where I need to remove a person from a busy background. I was hoping Affinity Photo had good, or better, tools for cutting out parts of a photo than Photoshop has, but so far I'm finding the opposite. It takes a lot of time to get a good selection, and it's not terribly clean requiring a lot of manual touch-up. But I think for me it's the Refine option in AP that isn't working very well for me, it doesn't seem to find edges very well at all and bleeds the selection over edges into parts of the image I don't want to select. I notice you don't use it in your process, is that why? 

 

[firstdefence]

2 minutes ago, TomHu said:

I notice you don't use it in your process, is that why? 

No, I can get good results using refine but I find the method outlined quicker and cleaner, I use a tablet and pen to select, its more intuitive and quicker than using a mouse.

[Sara72]

Hi,

I found this tutorial very useful in refining and cutting an image: