Subtracting multiple white background areas from an image in Designer?

[Ballyshannon]

I have an image with four areas of white background that need to be subtracted. Any suggestion(s) how to do this? I tried using the Alternate Fill option but doesn't work.

Forgot to specify Affinity Designer.

[HVDB Photography]

Difficult to say without seeing the image !

[Pšenda]

https://affinity.help/photo/en-US.lproj/pages/Filters/filter_eraseWhitePaper.html

[Ballyshannon]

Here's the image. I want to use the small finder scope attached to the telescope for another project and have it outlined for subtracting the telescope. There are three other areas of white outlined in red that I want removed from the finderscope.

Finderscope_subtract open spaces.afdesign

 

UPDATE: Figured it out. I first moved the main image into the outline layer to remove the main telescope image, leaving only the finderscope. I then moved each of the curves outlining the areas I wanted removed to the top of the layers list (above the grouping layer). I then selected all layers and used the subtract function to remove the open spaces. Worked great.

[gdenby]

Hi, Ballyshannon,

This what you are trying to make?

Finderscope_sub ope space.afdesign

 

[toltec]

If you want to do this as a pixel selection, youhave already done most of the work. I used your path for the outline, below.. 

However, the first thing you must do is turn the layer into a Pixel layer. It is currently an Image layer. Right click and then Rasterise.

If you draw the path around the whole finderscope outline (as you have) fill it with a colour (any colour) and then Ctrl + click on the path's layer thumbnail. That makes a pixel selection, click the image layer to move the pixel selection to that layer, then copy it, Ctrl + C. Create a new document from that. File > New From Clipboard.

You can draw around the bits you want to erase, and do pretty much the same thing. Fill with a colour and Ctrl + click on the path's thumbnail to make a selection, then click on the image layer but this time, press Delete to make a hole. Deleting the shape layers afterwards. You can refine the edges with the Refine Edges Tool.  You could also use the paths to ‘clip’ the image, though that’s not quite the same as you can’t refine the edges.

Obviously the more accurately you draw the paths, the better the result. 

You did a pretty good job 

 

[Ballyshannon]

Thanks for the input! As mentioned in my update above, I was able to figure it out and @gdenby, it appears we used the same process. Here is the final result added to the Celestron 11" SCT I created from scratch. Still doing some tweaking, but it's getting close. I've only been working with Designer for about a month now, and am really enjoying it.