I've been experimenting with the Free version of Luminar 4

[Glen Barrington]

Sheesh! ACDSee doesn't have anything to worry about! If you want to read my thoughts, you can find it on DPR in the retouching forum.

But the one interesting tool they have is an automated sky replacement. As near as I can tell, it uses an AI version of something similar to Pixel Targeting tweaked for sky replacement.

I suspect this because the new sky tends to bleed into the portion of the photo where it should be masked out. In experimenting with L4 sky replacement, I noticed that the replaced sky would only bleed into areas that are the same color and luminosity as the sky, or very close to it. If so, I should think this is a quick and dirty way to create the sky replacement mask, but at the cost of quality work.

I wonder if a series of actions could be created to do this in ACDSee Ultimate? I suspect a Pixel targeted mask could be coupled with layers to 'touch up' the mask before sky replacement, and thereby eliminate the bleed-over. It might be a cheap and easy way to add buzz to a new release.

Does anyone have any ideas on how to go about this in a manual fashion?

[Greyfox]

Glen Barrington

There is a quick ACDSee tutorial on sky replacement here https://www.google.com/search?client...Y4-EPy8WB2AI27

The bleed as you call it in Luminar 4 as I understand it was considered somewhat beneficial because a change of sky between say a bright mid day sun and a gold sundown in the real world would affect the coloring of other objects in the image.

It is particularly noticeable in real estate photographs when you substitute a bright blue sky over houses that have white tiled roofs. There are some adjustments in the L4 sky replacement tool to manipulate this, but in the end one nearly always had to use masking. The L4 process in my view is based on blending as is the ACDSee tutorial above.

On a side note. It was and is possible to get good results from the L4 sky replacement tool, but it did cause some angst. Because of the "AI" tag, some expected to be able to get professional results with no skill requirement. For sky replacement to be believable that isn't the case.

[Regor250]

This is also a feature in ACDSee Gemstone. That said, I find that these AI selection tools while working great on "easily selected subjects/skies" in general, do struggle when the background (or foreground for skies) becomes more complex. Bright skies are easy, just do a luminosity selection. Things get more difficult when you separate small details with antialised edges in a very different color than the new background. I wish ACDSee would create a "re-antialise edges" function, that would be awesome in blending small details with a new background, while preserving them.

[Greyfox]

Regor250

Yep, try replacing an overcast sky showing through a tree or trees with open leaves and thin branches with a bright sunny sky. or replacing a sky behind a subject with blonde flyaway hair.

Sky replacement is fairly common for photos used for real estate sales advertising. You probably won't see many advertisements where the property images have a dull or stormy sky, but that may well be what was there the day the photos had to be taken.

[Glen Barrington]

Glen Barrington

The bleed as you call it in Luminar 4 as I understand it was considered somewhat beneficial because a change of sky between say a bright mid day sun and a gold sundown in the real world would affect the coloring of other objects in the image.

I

That sounds like marketing spin to me! Especially so since the bleed is so, SO obvious!

Actually, I'm not all that interested in sky replacement as such, just that I found it interesting that I could see a 'synchronicity' between L4's sky replacement and Pixel targeting.

At any rate, ACDSee remains safe from Luminar's customer poaching!

[Greyfox]

..Especially so since the bleed is so, SO obvious!

For those who have spent the time to learn how to get the best out of the sky replacement tool, bleed is not an issue.

The screen shot below shows a 2 minute sky replacement with a change in general warmth, done in L4.



L4 is not be any means one of my favorite applications, but it does have some useful tools. I use it as a plug in from ACDSee's Edit mode.

[hectorsm]

Glen Barrington

There is a quick ACDSee tutorial on sky replacement here https://www.google.com/search?client...Y4-EPy8WB2AI27

The bleed as you call it in Luminar 4 as I understand it was considered somewhat beneficial because a change of sky between say a bright mid day sun and a gold sundown in the real world would affect the coloring of other objects in the image.

It is particularly noticeable in real estate photographs when you substitute a bright blue sky over houses that have white tiled roofs. There are some adjustments in the L4 sky replacement tool to manipulate this, but in the end one nearly always had to use masking. The L4 process in my view is based on blending as is the ACDSee tutorial above.

On a side note. It was and is possible to get good results from the L4 sky replacement tool, but it did cause some angst. Because of the "AI" tag, some expected to be able to get professional results with no skill requirement. For sky replacement to be believable that isn't the case.

I saw the video. It's interesting but a lot of work. The results are not that great even after multiple brushes and layering. This is something I'll rarely need but mighty be useful at times.

Hector

[Greyfox]

I saw the video. It's interesting but a lot of work

If you take away the time Alec spends explaining what he is doing because it is a tutorial, the process itself would probably take him only a couple of minutes. I don't see that as a lot of work. For images that require replacing the sky I would probably spend more than that just choosing a suitable sky that matches the lighting, and "feel" of the original shot.

Here is one done in ACDSee in around 2 minutes using the method used in the video. Note that the thin rigging wires are still intact (though they do pixelate quite quickly with the low res screen shot) and there is some bleed on the masts which I haven't bother to remove.

[hectorsm]

If you take away the time Alec spends explaining what he is doing because it is a tutorial, the process itself would probably take him only a couple of minutes. I don't see that as a lot of work. For images that require replacing the sky I would probably spend more than that just choosing a suitable sky that matches the lighting, and "feel" of the original shot.

Here is one done in ACDSee in around 2 minutes using the method used in the video. Note that the thin rigging wires are still intact (though they do pixelate quite quickly with the low res screen shot) and there is some bleed on the masts which I haven't bother to remove.

I've never done this kind of work before, so it seems complicated to me. I guess it's more a matter of learning how to use the tools. Once you learn the tools and what to do, it may not be as bad as it looks. Where do you get your sky's? I might try it, just to learn.

Hector

[Greyfox]

Where do you get your sky's? I might try it, just to learn.

As Alec mentioned in the video, you can download sky images from free on line sources like Unsplash.

I have ones I have downloaded, sky packs I purchased some time ago (but rarely used because they tend to be too dramatic). Mostly though I use ones I have taken myself.

I try to take the images from places where there is a horizon, but with minimum protrusions of objects into the horizon (so taken from a hill or high point, or from a beach). I post crop the bottom of the images at or close to the horizon (so the bottom edge is effectively the horizon point). Knowing where the horizon was helps when positioning the sky on the image.

If you take your own sky images, you can choose ones where the light is from the left, from the right, or evenly spread. Morning shots with the sun rising, evening towards sunset, lots of clouds, relatively clear sky's etc. I would avoid using "spectacular sky shots" at least in the beginning, because there will be few images where they will look real. Remember that the main subject in photos where sky changes are considered would rarely be the sky itself.

Other than shots taken for a specific purpose, like real estate sales photos, or where for artistic reasons one wants to change the tone of an image, most sky changes are probably only considered for images where the sky, or parts of it are blown, but the rest of the image is worth keeping. For realistic results with that type of image, the replacement sky would be expected to be relatively bright and clear.

[hectorsm]

As Alec mentioned in the video, you can download sky images from free on line sources like Unsplash.

I have ones I have downloaded, sky packs I purchased some time ago (but rarely used because they tend to be too dramatic). Mostly though I use ones I have taken myself.

I try to take the images from places where there is a horizon, but with minimum protrusions of objects into the horizon (so taken from a hill or high point, or from a beach). I post crop the bottom of the images at or close to the horizon (so the bottom edge is effectively the horizon point). Knowing where the horizon was helps when positioning the sky on the image.

If you take your own sky images, you can choose ones where the light is from the left, from the right, or evenly spread. Morning shots with the sun rising, evening towards sunset, lots of clouds, relatively clear sky's etc. I would avoid using "spectacular sky shots" at least in the beginning, because there will be few images where they will look real. Remember that the main subject in photos where sky changes are considered would rarely be the sky itself.

Other than shots taken for a specific purpose, like real estate sales photos, or where for artistic reasons one wants to change the tone of an image, most sky changes are probably only considered for images where the sky, or parts of it are blown, but the rest of the image is worth keeping. For realistic results with that type of image, the replacement sky would be expected to be relatively bright and clear.

Just for fun, here's my attempt. It's okay but not perfect. The tree branches in the sky area have a blue tint on them, and the details on top of the mountain appear to have been lost. My skill with the edit mode tools is very limited so it's very possible the results can be improved. I can probably fix the tree branch color with a Nik color control point, but the top edge of the mountain it's more difficult.



This is not something I'll do often, but it's good to know it can be done within ACDSee without having to go to an external editor.

I'm not sure how to post the images here that will allow resizing. Sorry about that.

Hector

[Regor250]

The blend mode method is the quick way of swapping skies, but the color blend is applied to all colors that are lighter than the new sky image's corresponding pixels, hence the blue tinge in the foliage. Sometimes you just can't avoid masking part of the image and every image is different, but nothing here than you can't do with ACDSee. Curious, how did Luminar handled that image?

[Greyfox]

..Curious, how did Luminar handled that image?

Not sure if hectorsm has Luminar 4, but here is a quick L4 effort.
I could only get a low res 300 x 449 image from the forum post, so did an initial enlargement in Topaz Gigapixel AI, then ran L4 as a plug in from ACDSee.

[hectorsm]

The blend mode method is the quick way of swapping skies, but the color blend is applied to all colors that are lighter than the new sky image's corresponding pixels, hence the blue tinge in the foliage. Sometimes you just can't avoid masking part of the image and every image is different, but nothing here than you can't do with ACDSee. Curious, how did Luminar handled that image?

I've downloaded and installed Luminar to see how well it handles the sky replacement. I've also decided to start with the original undeveloped raw version instead of the previous processed version. Here is a comparison of the three.



I'm getting better results with Luminar with just a few click. It does a better job blending the two images and with no color cast. Still, I have no plans on using Luminar as my main raw processor. I like how ACDSee features better. I will probably use Luminar in cases like this.

Hector

[hectorsm]

Not sure if hectorsm has Luminar 4, but here is a quick L4 effort.
I could only get a low res 300 x 449 image from the forum post, so did an initial enlargement in Topaz Gigapixel AI, then ran L4 as a plug in from ACDSee.

Sorry for the small images. I kept getting some kind of error when I tried uploading the full size. The images in my previous post should be a little bit better but still not at full res. I'm still trying to learn how to post the images.

Hector