Replacing the sky

[Riftvalley]

Hi,
Is there a procedure to replace the sky in an image. I need to brighten a number of images shot on an overcast day. I have tried introducing a new sky and it works very well, by using the pen tool and a bit of patience and a touch of feathering.

Where I come unstuck is where a tree is silhouetted against the sky, I wonder if anyone has a way to make a tree look ok - I cannot imagine trying to trace round all the leaves!!! I did try cutting out the leaf parts and using light and dark cotones for sky and leaves respectively and this is reasonable, but not perfect.

I attach the sort of thing I need to put a better sky behind (the example I have selected has some purple fringing that is not representative).

Kind regards

Martin

[handrawn]

try giving it a stained glass transparency - that will remove all the white, and take it from there ?

[steve.ledger]

I'd try MEHDI eraser.

[Riftvalley]

Many thanks for the swift reply,
I have googled Mehdi eraser and downloaded it I will try it out tomorrow morning.

I have tried the one in the live effects drop down - works great. I will try also the Mehdi Eraser Genuine. This will saves a great deal of work.

Kind regards

Martin

[handrawn]

one of the 2 mehdi erasers comes as a standard live effect in xara - which one to use is maybe a personal thing

as free plugins go they are good

[iamtheblues]

As an alternative to the Mehdi plug-in, after following Steve J's advice re stained glass transparency, I cloned the photo, gave the clone a light blue contone, then selected the structure in the bottom left corner and sliced it out of the clone, exposing the full colour version below. Probably wouldn't work on all photos, I know, but seems to on over-exposed skies. But it did remove most of the purple fringe around the edges of the leaves.
Saludos,
Bob.

[Riftvalley]

Thank you for all your advice,

I am finding that where the sky is just part of the image there is a lot of work involved in getting everything to balance. This is mainly because the Mehdi eraser introduces some transparency.

My work flow is first to create a new layer called 'sky', move this below the main layer. I then trace a shape on the image that includes the foliage, in the layer gallery I select the shape and the image then press ctrl+K to copy both. I then take the top two copies (mask and image) and subtract. The clipped photo I then hide. Then I do a intersect of the original image and the shape, I then use the MEHDI plug-in on the foliage part of the picture. Then I restore the hidden image.

The next part is to adjust the balance of the three components of the image (and adjust the settings in MEHDI eraser) to make it look continuous. Final part is to crop the images and merge them into a jpg. I some images the traced shape is made up of several parts that I join before doing the subtraction and the intersection.

Fortunately these images are going on a webpage so, as I am working at fairly high resolution by the time they get down to something like 700X700pix they don't look too bad.

But quite a lot of work with about 100 images to work through!!!

I will try the stained glass method also, to see how much effort is involved with this approach.

Also, if the balance between the sky and the foliage is difficult then I find that often I can use a linear transparency to keep a strong colour for the foliage and blend it out using the transparency tool.

Thanks again

Martin