Compositing tool

[admin]

Overlays, Underlays and erasing areas
When you add an overlay, you add a new image on top of your existing image. You then use the brushes to select which parts of the new image you want to be transparent. You can use this to add new objects on top of your picture.

When you add an underlay, you add a new image underneath your existing image. You then use the brushes to select which parts of your *existing* image should allow the underlay to show through. This is basically making your existing image transparent in various places. You can use this to replace backgrounds or skies.


Moving Scaling and Rotating pictures
To place an overlay or underlay click on the "Move, Rotate and Scale" button at the top of the Composite Panel. This allows you to move overlays and underlays around on the screen.

N.B. You can only move overlays and underlays, not your original image.

[dood47 Profile]

I can't work out how to get two photos selected at the same time. Once I've chosen my first photo, how do I then add the second one to become my underlay?

[admin]

Hi,

Once you've loaded a photo:

+ Click on the Composite tool on the right
+ Click on "New" next to Underlays to add a new sky or something else behind your picture (or Overlay for something infront of your picture)

The "Replacing the background" tutorial takes you through the stages of replacing a background step by step.

Tony

[towerengineering Profile]

Can I replace an underlay with a different image. I have done one composite and saved it as a session. Now I want to come back to it and replace the first underlay image with an alternative - is this possible?

[admin]

Yes, just delete the first underlay by pressing the X button, then add your alternative underlay image by pressing New Underlay.

What we don't have as easily is the ability to replace the underlay but keep the selection the same. To do that, you will need to right click on the composite tab at the top then choose manual edit. You will see the nodes that create the composite you've done. One of them is Load image, which you can double click on and choose a new filename. You can then click on Effect output to see your original underlay replaced. You can then save the new result.

Tony

[towerengineering Profile]

Many thanks Tony - works just fine. It is good that after spending quite a lot of time getting a selection right for compositing it is possible to alternate the underlay image without having to process a new selection. Maybe a shortcut button to do this in future updates would be handy ??

Cheers,

John.

[admin]

I'm not sure exactly what you're asking. Did you manage to alternate the underlay image without processing a new selection using the steps I described (if you got stuck, let me know), or do you just mean it would be good to have a shortcut through that process?

Cheers,

Tony

[towerengineering Profile]

Hi Tony. Yes I managed to alternate the underlays without having to go through the process of a new selection and yes maybe a shortcut button labelled 'Replace Underlay' or similar in future program upgrades might be an idea? Thanks for your help again - cheers.

[alicemarie32 Profile]

hi everyone. I am erasing the background from an overlay photo for a sports collage. However, the photo is a lil blurry and its crystal clear! Any suggestions??

[admin]

If I understand you correctly, you're replacing the background of a blurry photo with a sharp photo and that looks wrong? If you load in the background first and search in the gallery for "blur" you'll find a few effects that can blur it. If you save out a blurred version you can then composite that version behind your blurred photo and it won't look so out of place.

Kind regards

Tony