resizing the canvas

[blackest]

Hi what i'm trying to do is mirror a photograph on all sides.

so if it was say 500 by 400 i might change the canvas to 800 by 500 duplicate the photo and flip it.

The problem is i can't quite get a perfect line up. 

is the top left corner pixel 1,1 or 0,0 it seems like there is a few pixels gap.

 

maybe its just me

 

 

 

[toltec]

Have you tried with snapping?

[R C-R]

The top left corner is at 0,0. The gap you see may be an artifact of rendering the document at a zoom level that does not display everything with pixel perfect accuracy due to antialiasing -- try viewing at 100% zoom level to see if it still appears.

[blackest]

ok 

i have an image of 4056 x 2535.

I expand the canvas to 12168 x2535 holding the background to the middle.

cmd j

it looks like i have 3 objects lining up at 

0,0 is top right of the left mirror  4056,0 is the top left (its flipped horizontal)

the middle object 

TL 4056,0 TR 8112,0 

The right object

TR 8112,0 TL 12168,0 

 

while they are 3 then sometimes you see the line sometimes you don't at 100% you don't merging them together the lines disappear at all zoom levels.

The merge gives you a new layer. 

it seems at first logical that if the first is from 0,0 to 4056,0 then the next should be at 4057,0 

or perhaps 0,0 to 4055 and the next 4056,0 to 8111.

but the transform tool is giving the outside edges  of the object not pixel coordinate which makes perfect sense and easier math too

 

Thank you for your assistance, now if only I could automate it.

[R C-R]

I don't think there is any way to automate this but there is a way to reduce the number of steps that also makes the math trivially simple. You don't say if you are using Affinity Designer or Affinity Photo but the basic idea is the same in either one:

 

1. Let the app do the math to resize the canvas, using an appropriate anchor point:

 or the equivalent for Photo: 

You should now have the photo perfectly centered on a canvas 3X its width.

 

2. Enable Snapping & make sure that at least the "Snap to spread" option is checked.

 

3. Select the photo & duplicate it in place using CMD + J (Mac) or Control + J (Windows).

 

4. To flip & position this copy in one step, grab its right center bounding box control handle & drag that to the left until it snaps to the left margin of the canvas.

 

5. Either duplicate this copy & drag it all the way to right until it snaps to the right margin of the canvas or as in step 4 duplicate the original (center) photo layer & grab its left center bounding box control handle & drag that to the right until it snaps to the right margin of the canvas.

 

6. You should end up with three photo layers aligned exactly edge to edge. 

[carl123]

12 hours ago, blackest said:

Hi what i'm trying to do is mirror a photograph on all sides.

so if it was say 500 by 400 i might change the canvas to 800 by 500 duplicate the photo and flip it.

The problem is i can't quite get a perfect line up.

is the top left corner pixel 1,1 or 0,0 it seems like there is a few pixels gap.

 

maybe its just me

 

 

 

You can also do all of this without having to calculate the new canvas size or do any other calculations or do any manual movement of the photos

Example:

1. Duplicate the photo
2. Set the x position of the duplicate to the width of the photo (all done in the Transform panel)
3. Select Document > Unclip Canvas
4. Flip the duplicate (using Arrange > Flip Horizontal)

[R C-R]

2 hours ago, carl123 said:

3. Select Document > Unclip Canvas

Does Designer have an Unclip Canvas option?

[carl123]

3 minutes ago, R C-R said:

Does Designer have an Unclip Canvas option?

I don't think it has.

But the OP mentioned "mirroring a photograph" so I assumed he/she is using Affinity Photo

[JimmyJack]

Nice techniques, both of you.

 

1 hour ago, R C-R said:

Does Designer have an Unclip Canvas option?

 

In Designer, you could select both and click create Artboard from selection.

[carl123]

Or (if you don't want an Artboard) just select both, copy and File > New from Clipboard

[blackest]

On 8/28/2017 at 3:57 PM, carl123 said:

I don't think it has.

But the OP mentioned "mirroring a photograph" so I assumed he/she is using Affinity Photo

I use both actually. This actually started for me due to something I saw in a pdf file in designer one of the images had been extended on top by mirroring the top edge. The background was subtle enough so it wasn't obvious.   It pretty much depends on the detail but mirroring round the edges can give you a larger image to crop sometimes. Also works quite well for a wrapped canvas print you just use the mirrored parts for the side edges.

 

I will try your technique  saves having a calculator around.

 

It works well, much faster to apply