The document discusses gesture-based computing, highlighting the differences between touchscreen and freeform gestural interfaces that detect physical movements without traditional pointing devices. It emphasizes the principles of direct manipulation and Fitts' law, noting the importance of target size and proximity for effective gesture recognition. Additionally, it explores challenges with complex gestures and the limitations of current gesture vocabularies, suggesting that less complicated gestures are more user-friendly.

1. GESTURE BASED
COMPUTING
Paul Coulton
Banksy

2. GESTURE BASED
COMPUTING
Paul Coulton
O’Sullivan
and Igoe
Banksy

3. GESTURAL INTERFACES
Allows physical movements to be detected by a digital system
Dan Saffer
without the aid of a traditional pointing device.

4. A wave, a head nod, a touch, a toe
tap, or even a raised eyebrow could
be a gesture
GESTURAL INTERFACES
Allows physical movements to be detected by a digital system
Dan Saffer
without the aid of a traditional pointing device.

5. TANGIBLE INTERFACES
Providing a physical form of digital information and facilitates the
direct manipulation of the associated bits

6. Text
Jesper Juul
MIMETIC INTERFACES
Mimetic interfaces require players to perform actions that
closely resemble the physical activity required in reality.

7. NATURAL
USER
INTERFACES
“natural refers to the user’s
behaviour and feeling during the
experience rather than being
the product of some organic
process” Wigdor and Wixon
and indeed suggest a natural
experience “is NOT best
achieved through mimicry”

8. TYPES OF
GESTURAL
INTERFACE
Most gestural interfaces can
be categorised as either
touchscreen or free form.
Touchscreens require the user
to be touching device directly
whereas freeform systems do
not.
Dan Saffer

9. DIRECT VS INDIRECT
MANIPULATION

10. Direct manipulation features a
natural representation of task
objects and actions promoting
the notion of people
performing a task themselves
(directly) not through an
intermediary.
DIRECT VS INDIRECT
MANIPULATION

11. MICE VS FINGERS
Dan Saffer

12. A cursor is often unnecessary
since the user is not constantly
pointing at something. Finger
moves from point to point
whereas mouse makes a trail.
MICE VS FINGERS
Dan Saffer

13. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
MICE VS FINGERS
Dan Saffer

14. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but
should be used with caution. A
threshold has to be set during
which two touch events at same
location count a double click.
MICE VS FINGERS
Dan Saffer

15. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but In general gesture interfaces don’t
should be used with caution. A employ the right click to bring up
threshold has to be set during another option as this tends to go
which two touch events at same away from direct manipulation
location count a double click. philosophy
MICE VS FINGERS
Dan Saffer

16. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but In general gesture interfaces don’t
should be used with caution. A employ the right click to bring up
threshold has to be set during another option as this tends to go
which two touch events at same away from direct manipulation
location count a double click. philosophy
Drop down menus generally don’t
work very well for same reason
as right click menus combined
with limitations over hover.
MICE VS FINGERS
Dan Saffer

17. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but In general gesture interfaces don’t
should be used with caution. A employ the right click to bring up
threshold has to be set during another option as this tends to go
which two touch events at same away from direct manipulation
location count a double click. philosophy
Cut and Paste is now
Drop down menus generally don’t
implemented on touch screen
work very well for same reason
device although presents difficulty
as right click menus combined
for accurate placement due to
with limitations over hover.
size of fingers
MICE VS FINGERS
Dan Saffer

18. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but In general gesture interfaces don’t
should be used with caution. A employ the right click to bring up
threshold has to be set during another option as this tends to go
which two touch events at same away from direct manipulation
location count a double click. philosophy
Cut and Paste is now
Drop down menus generally don’t
implemented on touch screen
work very well for same reason
device although presents difficulty
as right click menus combined
for accurate placement due to
with limitations over hover.
size of fingers
As humans have a limited number
of fingers we have a limit on
selecting multiple items. Normally
this means some form of select
mode is used.
MICE VS FINGERS
Dan Saffer

19. A cursor is often unnecessary
Hovers and mouse over events
since the user is not constantly
are not employed as this cannot
pointing at something. Finger
be detected through touch
moves from point to point
screens.
whereas mouse makes a trail.
Double click can be done but In general gesture interfaces don’t
should be used with caution. A employ the right click to bring up
threshold has to be set during another option as this tends to go
which two touch events at same away from direct manipulation
location count a double click. philosophy
Cut and Paste is now
Drop down menus generally don’t
implemented on touch screen
work very well for same reason
device although presents difficulty
as right click menus combined
for accurate placement due to
with limitations over hover.
size of fingers
As humans have a limited number Its hard to do an Undo gesture
of fingers we have a limit on once a gesture is done therefore
selecting multiple items. Normally its better to have an easy way to
this means some form of select cancel or directly undo the
mode is used. action.
MICE VS FINGERS
Dan Saffer

20. FITTS LAW

21. Fitts's law is a model of human
movement relating to pointing
that predicts that the time
required to rapidly move to a
target area is a function of the
distance to the target and the
size of the target.
FITTS LAW

22. Put simply a large object closer
to the user is easier to point to
than a large one far away.
Fitts's law is a model of human
movement relating to pointing
that predicts that the time
required to rapidly move to a
target area is a function of the
distance to the target and the
size of the target.
FITTS LAW

23. FITTS LAW

24. This law is equally applicable to
gestures. Visual targets should be
designed to be close to the user to
avoid reaching across the interface.
Objects to be manipulated should
be large enough to accomodate
human finger
FITTS LAW

25. FINGER TIPS
A general guide for the size
acceptable targets ideally
should be no smaller than the
smallest average finger pad,
typically a 1cm (0.4 inch)
diameter is used.

26. PPI
What 1cm translates to in
pixels depends on the pixel
density or Pixels Per Inch (PPI).
Once you have PPI simply
times by 0.4 to get number of
pixels of your touch point

27. Model Diagonal Pixels PPI
iPhone 3GS 3.5” 320X480 163
iPhone 4 3.5” 640x960 326
iPad, iPad2 9.7” 1024x768 132
Google Nexus 1 3.7” 480x800 252
Motorola Droid X 4.3” 854x480 228
Nokia N8 3.5” 640x360 209
Nexus S 4.0” 480x800 235
EXAMPLE PPI

28. Dan Saffer
ICEBERG TIPS
These are controls that have larger targets than what is visible.
The implication is you need more space between objects.

29. Dan Saffer
OK
ICEBERG TIPS
These are controls that have larger targets than what is visible.
The implication is you need more space between objects.

30. ADAPTION
The keyboard on the iPhone
actually uses some of the
smallest targets at 5mm (0.2
inches). It uses adaptive
targets to get over this
limitation.
Dan Saffer

31. Dan Saffer
ADAPTIVE TARGETS
These are created algorithmically by guessing the next item the
user will touch and increasing the touch target appropriately.

32. Dan Saffer
1st 2nd
ADAPTIVE TARGETS
These are created algorithmically by guessing the next item the
user will touch and increasing the touch target appropriately.

33. Select Tap Drag Flick
Pinch Spread Slide Left to Right Slide Up and Down
TOUCHSCREEN PATTERNS

34. CURSE OF TWO FINGERED
ZOOM!

35. The more complicated the
gesture the fewer people will
use it!
CURSE OF TWO FINGERED
ZOOM!

36. USER GENERATED

37. FREE FORM GESTURES

38. Spatial Gesture
Models
3D Model Based Appearance Based
Deformable 2D
Skeletal Volumetric Image Sequences
Templates
NURBS Primitives Super Quadratics
SPATIAL GESTURE MODELS

39. Pointing Pointing Wiimote
EXISTING FREE FORM
GESTURE PATTERNS

40. Fukuda’s
Proximity Wave AirSwitch
Automatic Light
Door
EXISTING FREE FORM
GESTURE PATTERNS

41. Hands Inside Rotate Nokia
Dyson Air
N93
Blade
EXISTING FREE FORM
GESTURE PATTERNS

42. Step Shake
Dance SE W910i
Mat
EXISTING FREE FORM
GESTURE PATTERNS

43. Clap Tilt Wii
Balance
Board
EXISTING FREE FORM
GESTURE PATTERNS

44. Moving a Cursor or Avatar Select Swith On/Off
Slide Tap Tap
Head Tilt Stare Flick
Turn Head Left/Right Point Stomp
Lean Torso Left/Right Hand Gun Wave
Point Clap
Snap
Confirmation Cancel
Nod Shake No
Smile Frown
Okay Thumbs Down
Thumbs Up Stop
Nose Tap
MATCHING GESTURE TO
Dan Saffer ACTIVITY

45. Timo Arnall
COMMUNICATING GESTURES

46. KINECT
Xbox game controller proving a natural user interface using
gestures and spoken commands

47. Infrared laser projector combined with a
Sensor's microphone array enables
monochrome CMOS sensor captures
acoustic source localisation and ambient
video data in 3D under any ambient light
noise suppression
conditions
KINECT

48. KINECT SDK

49. SDK includes:
1. Raw sensor streams: Access to low-level
streams from the depth sensor, colour camera
sensor, and four-element microphone array.
2. Skeletal tracking: The capability to track the
skeleton image of one or two people moving
within the field of view for gesture-driven
applications.
KINECT SDK

50. SDK includes:
1. Raw sensor streams: Access to low-level
streams from the depth sensor, colour camera
sensor, and four-element microphone array.
2. Skeletal tracking: The capability to track the
skeleton image of one or two people moving
within the field of view for gesture-driven
applications.
3. Advanced audio capabilities: Audio processing
capabilities include sophisticated acoustic noise
suppression and echo cancellation, beam
formation to identify the current sound source,
and integration with the Windows speech
recognition API.
4. Sample code and Documentation.
KINECT SDK

51. CONCLUSIONS
• Currently gestures can be classified predominantly as touch or
free form
• The finger is not a direct replacement for the mouse.
• The more complicated the gesture the fewer the number of
people who will use it successfully.
• If gestures are not obvious to the user the need to be clearly
communicated
• As yet our vocabulary of free form gestures is limited and
needs much more development.
• Free form gestures should make the user embarrassed.

52. @mysticmobile
QUESTIONS