http://code.google.com/p/magicktiler

1. M agickTiler
A Java tool and embeddable library for converting images into
formats suitable for publishing as zoomable Web images.
http://code.google.com/p/magicktiler/

2. Image Tiling B asics – The
P yramid
Y
Y/2
Y/4
Y/8
X X/2 X/4 X/8
(some math...)
No. of zoom levels = ⌈ log 2 max { x
tilewidth
,
y
tileheight }⌉ + 1

3. Tiling Schemes
• Zoomify
• TM S
• Google M aps
• M S D eep Zoom
• …
Variations are in the details…
tile naming, directory layout, file formats and sizes,
descriptor files, handling of irregular tile sizes.

4. TM S 1
<zo o m -level>
<c o lum n>
ro w .jpg / png
ro w .jpg / png
…
/0/2.jpg /1/2.jpg /2/2.jpg
/0/1.jpg /1/1.jpg /2/1.jpg
/0/0.jpg /1/0.jpg /2/0.jpg
Tile (x and y) M U S T be n x tilesize!
B orders M U S T be top/right.
1
as supported by O penLayers

5. Zoomify
<T ileG ro upX >
<level>-<c o l>-<ro w >.jpg
<level>-<c o l>-<ro w >.jpg
…
-0-0.jpg -1-0.jpg -2-0.jpg
-0-1.jpg -1-1.jpg -2-1.jpg
-0-2.jpg -1-2.jpg -2-2.jpg
Irregular tiles M U S T be
bottom/ right.

6. Zoomify: TileGroups (The Tricky
P art)
●
Starting with the lowest zoom level (1x1 tile)
●
Count! (left->right, top->bottom)
●
Start a new TileGroup after 256 tiles!
5 6 7
1 2
0
8 9 10
3 4
11 12 13

7. Google M aps
• R esize the longest dimension to the closest 256n²
• Square the image using background-colour
bufer
• Tiles are square (256x256)
• Tiles per zoomlevel: 4zoomlevel
<o ut-dir> -0-0 -1-0 -2-0 -3-0
<level>-<c o l>-<ro w >.jpg
<level>-<c o l>-<ro w >.jpg
-0-1 -1-1 -2-1 -3-1
…
-0-2 -1-2 -2-2 -3-2
-0-3 -1-3 -2-3 -3-3

8. P erformance O ptimizations
• Striping
– The base image is cut into either horizontal or
vertical stripes to avoid operations on 'large'
images
– For each zoom level, the stripes are generated
based on the stripes of the previous
zoomlevel (stripes are merged)
• Single GM/IM operations where possible

9. C LI
usage: java -jar magicktiler [-b <color>] [-f <format>] [-g] [-h] -i
<input> [-l] [-o <output>] [-p] [-q <quality>] -s <scheme> [-v]
-b <color> background color, default=white
-f <format> tile format ('jpeg' or 'png'), default=jpeg
-g displays the GUI (ignores all other parameters)
-h displays this help text
-i <input> mandatory input file or directory
-l writes reporting information to a log file
-o <output> output directory (for tilesets) or file (for PTIF), default=.
-p generate an HTML preview file
-q <quality> JPEG compression quality (0 - 100), default=75
-s <scheme> mandatory tiling scheme ('tms', 'zoomify', 'gmap' or 'ptif')
-v validate the input instead of generating a tileset
Example: java -jar magicktiler.jar -s tms -f jpeg -i image.tif -p

10. Finally, some Java!