Scaling to a reference object?

[jimklo]

I have a scanned image that I’m trying to edit that I’ll eventually export for cutting on a Cricut. 

Trying to figure out if Photo (or Design) on iPad has the ability to scale/resize a layer or object  based upon a reference object? 

eg: I’ve got a photo of ruler that I imported, I now want to scale and deskew the photo so the objects in the image are actual size and proportionally correct.  

For scaling, I could create a 1” square and then try to scale the imported image to align with the 1” square, but this is complicated as there doesn’t seem to be a way to designate an arbitrary point as the anchor point for the scale operation. Is there a simpler way?

I’m used to this sort of technique in CAD (And even Photoshop) where you select an object, define an anchor point, a reference point, and then the third point moves the reference point to the new location scaling the whole object proportionally.  

Similarly I would also need to deskew the image (remove any keystone effects from perspectives) but can’t seem to figure out how this is done within Affinity. I don’t see how I would do arbitrary transform of an image at all (other than in the limited transform studio on the right side).

Is there a way to do this or something similar in Affinity?

[DM1]

7 hours ago, jimklo said:

Similarly I would also need to deskew the image (remove any keystone effects from perspectives) but can’t seem to figure out how this is done within Affinity. 

Affinity Photo has a Perspective filter in the Filters studio that will address perspective issues. Design does not. It is possible to resize a layer in either, but not I think, relative to a reference object. You can set up a grid to possibly use as a size reference. 
Maybe the mods or others can suggest better alternatives.

[Dan C]

Hi jimklo,

Welcome to the forums

9 hours ago, jimklo said:

Trying to figure out if Photo (or Design) on iPad has the ability to scale/resize a layer or object  based upon a reference object? 

Unfortunately not currently, however this may be a feature we add in a future update.

In the meantime, DM1's suggestion of using a grid will most likely be the best option here, although this will still require some manual scaling.

You can use the Transform Studio to input expressions for resizing or repositioning objects, but again this doesn't support using 'relative' points, my apologies!