Sky Eraser for YoWindow

Sky Eraser is an image editor designed with only one goal - remove the sky from a photo.

When the sky is removed, YoWindow can show live sky instead.
Live sky is a virtual copy of the actual sky.
Sun light, clouds and even Moon phase are reflecting the real life.

Your photo will be looking amazingly natural. Under any weather condition. At any time.

Here's a 30 second preview of photo landscapes inside YoWindow (after the sky was removed).

Sky Eraser BETA is distributed via special Hockey service.
You need to register on Hockey in order to access the build.
Click the link below and follow the instructions.
https://rink.hockeyapp.net/recruit/abc74b84b0b44145831b73b4ce2da4f7

ATTENTION: Sky Eraser requires a special library, called "Computer Vision" or "CV" installed on Android.
Sky Eraser is going to ask you to install Computer Vision.
Please install it, otherwise Sky Eraser will not be working.


Let’s remove the sky from a picture of London Eye wheel.


As soon as the picture is opened in the editor, Sky Eraser is trying to detect the sky automatically. The process takes 5 – 10 seconds.

The app will mark the sky regions very approximately with red color.
The regions marked in red will be removed from the picture in the end.

This is the result of the automatic sky detection for the sample picture.

The algorithm is not perfect.
Unfortunately, some regions of the sky have not been marked with red.
Especially inside the wheel.

We need to mark these regions manually.
There are 2 methods to mark the sky.

Method 1 – mark with your finger.

You just dragging your finger over the sky, effectively marking it.
Use red marker for this task.

If you made a mistake, no problem - remove the wrong mark with the red eraser.

Tap Undo to step back.

Advise: use pinch gesture to change the scale of the picture. When the picture is small you can mark a large portion of it with just one swipe of your finger.
If you want to mark a small detail - Zoom in.

Unfortunately, marking the sky this way is a very laborious process.
The second method is way more effective.

Method 2 - marking the colors of the sky.

Press CK (Color Killer) button.
Sky Eraser will enter “Color mark” mode.

Then you need tap a pixel of a color that is very similar to the color of the sky.
After that the app will mark in red the pixels similar to the pixel you tapped.

Repeat this process a number of times, until the whole sky is marked in red.

Unfortunately, some elements of a landscape could have a similar color to the sky.
In such a case, Sky Eraser marks these pixels in red, see the picture below (look at the water and the house).

The landscape will look poor if we leave the pixels untouched.

This problem is easy to fix with “eraser” tool.
Eraser removes the red marks.
Advice: scale the picture down with “pinch” gesture so your finger could cover a large region.

After the bad red pixels have been removed with eraser, the picture looks like this.

In case you made a mistake, just tap Undo to step back.

This is how the picture looks after the whole sky has been marked.

Horizon level

YoWindow needs to know where the horizon level is on the picture to display the sky naturally. Press "Horizon" button to set the horizon level.

ATTENTION: the sky will not be cut below the horizon level. Because there is no sense in this.

Preview

Tap Preview - see how the landscape will look inside YoWindow.
The pixels marked in red will turn transparent.
Drag over the picture to see how the landscape will look during the day and the night.

You can save and open the landscape from “YoWindow" gallery if you want to edit it later.
The product of Sky Eraser is a landscape file that you can open inside YoWindow.

In order to open the landscape inside YoWindow, you need to have the latest BETA version of YoWindow.

To open your landscape inside YoWindow, tap the landscape button (top-right corner) then choose "Open..." and find your landscape in YoWindow gallery.

Sky Eraser is being designed right now.
We need to know if the software is comfortable to use.
You are very welcome to share your thoughts or report errors and suggestions in our forum
http://forum.yowindow.com/viewforum.php?f=58

YoWindow team.
January 18 2015