Gallery Tilt Shift Plugin
What is it?
Gallery Tilt Shift Plugin is a filter for the Gallery application of the N9 (and N950) MeeGo devices which makes a picture look like a miniature.
From the Wikipedia,
Tilt-shift photography refers to the use of camera movements on small- and medium-format cameras, and sometimes specifically refers to the use of tilt for selective focus, often for simulating a miniature scene. Sometimes the term is used when the shallow depth of field is simulated with digital post-processing; the name may derive from the tilt-shift lens normally required when the effect is produced optically.
Making an photograph of a life-size location or object look like photograph of a miniature scale model is known as Miniature faking. There are several ways to achieve that result, and fake Tilt Shift is one of them.
Applying Tilt Shift to a picture:
- From the application grid, open Gallery
- Pick a picture with a size equal or smaller than 512x512px (see Known Issues below)
- Tap on the object menu and select Edit
- Tap on Tilt Shift
- Select the orientation of the focus (horizontal / vertical). In that orientation, the focused area will take all available space
- Select the radius of the focus: that will rule the size of the focused area in the other orientation
- Tap on the screen to center the focus around the given point
- Only PR >= 1.2 is currently supported.
- You will need to reboot to make the icon for the plugin appear properly
- Due to limitations in the current implementation of the filter, operating on images larger than 512x512 is very slow and causes artifacts.
Gallery is using MeeGo Image Editor to apply filters on images. Since it uses a plugin mechanism, it is possible to write new filters and have them appearing into the built-in Gallery.
MeeGo Image Editor uses tiling to operate on small portions of an image and avoid having to load it all into memory. While this approach works pretty well for many filters, it fails for those requiring context to be applied.
In the case of the Tilt Shift plugin, this is important because it has been implemented by:
- Blurring the image ussing a Gaussian Blur filter
- Keep an area of the image focused (either vertically or horizontally)
- Combine both parts of the image using a Gaussian filter (so the focus is lost gradually from the focused area to the rest of the image)
- Increase the saturation, so the colors seems those of a miniature
However, the Gaussian Blur needs a context when it is applied to a pixel, so when it reaches the borders of a tile, it will have to "guess" a pixel. The larger the Gaussian Blur kernel, the bigger the amount of pixels it has to guess. This produces very noticeable artifacts on the borders of the tiles. Besides, its performance is not very good, so applying it to a full size image takes a lot of time to finish.