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Initial version of the README using markdown syntax

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1 parent 0db4171 commit 6a10975032fc8c507c4f7d08ae13366aae114100 Simon Pena committed Mar 30, 2012
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  1. +0 −15 README
  2. +67 −0 README.md
  3. +5 −0 gallery-plugin-tiltshift.pro
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15 README
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-USAGE:
- * 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
-
-TODO
- * The Gaussian Blur algorithm is known to be slow: it will need some
- performance enhancements, besides the use of scanLines to access pixels
- * The Gaussian Blur filter makes artifacts on the borders of the tiles
-
-KNOWN ISSUES:
- * Input images are restricted to 512x512 in order to avoid the artifacts on
- the borders of the tiles.
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67 README.md
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+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] [1],
+> *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] [2]. 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
+
+Known Issues:
+-------------
+ * 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.
+
+In depth:
+---------
+Gallery is using [MeeGo Image Editor] [3] 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:
+
+ 1. Blurring the image ussing a Gaussian Blur filter
+ 1. Keep an area of the image focused (either vertically or horizontally)
+ 1. 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)
+ 1. 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.
+
+[1]: http://en.wikipedia.org/wiki/Tilt-shift_photography "Tilt-shift photography"
+[2]: http://en.wikipedia.org/wiki/Miniature_faking "Miniature Faking"
+[3]: https://maemo.gitorious.org/meego-image-editor/ "MeeGo Image Editor"
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5 gallery-plugin-tiltshift.pro
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TEMPLATE = subdirs
SUBDIRS = gallerytiltshiftplugin \
quilltiltshiftplugin
+
+OTHER_FILES += \
+ AUTHORS \
+ COPYING \
+ README.md

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