This presentation is the property of its rightful owner.
1 / 24

# Introduction to Jitter & Eyesweb PowerPoint PPT Presentation

Introduction to Jitter & Eyesweb. Volker Krüger Aalborg Media Lab Aalborg University Copenhagen vok@media.aau.dk. Introduction to Jitter & Eyesweb. What are Jitter and Eyesweb good for? Intuitive programming without programming!

Introduction to Jitter & Eyesweb

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

## Introduction to Jitter & Eyesweb

Volker Krüger

Aalborg Media Lab

Aalborg University Copenhagen

vok@media.aau.dk

### Introduction to Jitter & Eyesweb

What are Jitter and Eyesweb good for?

• Intuitive programming without programming!

• Big variety of functionality, incl. those that you have learned about

• Easy to use: Simply connect the function boxes

• Fast prototyping of ideas

• Jitter: Enhancement to Max/MSP

Agenda

• Intro to the Jitter specific issues

• Walk-through through some simple key-examples of Jitter and Eyesweb

### Matrices – Coordinates and Dimensions

Main important data type in Jitter: Matrices!

• Like images: they have

coordinates (x,y) and a size!

• Matrices can have several

dimensions: (x,y,z), (x,y,t)

### Matrices -- Planes

• When displaying, e.g., color images, each pixel is represented with 3 values: R, G, B!

• This is handled in Jitter with Planes.

• The A plane can be used for alpha blending.

### Allowed Datatypes

• Available datatypes are:

• char(8 bit), long(32 bit)

• float32(32 bit) , float64(64 bit)

• Functions usually adapt to input, no conversions needed!

• Parameter can be casted!

### Attributes and Arguments!

• Like in Max/MSP, Jitter functions can have

• Parameters

• Attributes

• Can be given as default values (order matters!)

• Attributes can be given explicitly (no blank after “@”):

• Can be changes during program execution

### Arguments or Attributes?

• Parameters can be passed as arguments to the functions:

• Arguments have to be passed before attributes are set.

• The following are equivalent:

### Getting Attribute Information

• In order to read out the attribute setting:

• To read out the value of a particular attribute:

### First Example: Playing a video

• jit.qt.movie reads video into memory: Parameters: size

• jit.window opens a window and attempts to display the movie. Parameters: window name, corner position of the window.

• No data is being copied, except for references!!

• And not data is being displayed either!!!

### The output has to be triggered!

• jit.window needs to be triggered!

• The example sends a bang every 40 ms.

• To restart the movie, set the attribute time to zero!

### Working with Matrices

• How to generate a matrix of a particular type:

• This reserves a region inside the computer memory for the data

• Parameters are planecount, type and dim.

### Printing matrix data

• To print the matrix data a special function exists:jit.print

• print left prints the reference to the matrix. It is a random name!

• setcell

• getcell

• setall

• clear

### Window object

• Having set the matrix values we can output the values visually using jit.pwindow

• It can be found in the task bar

### Setting the values of the entire matrix

• Setting each single matrix value separately is tedious.

• Alternative: Use loops and functions:

• Uzi <val> sends numbers 1 … <val>

### Matrices in Eyesweb

• Hardly ever used explicitly!

• Matrices are used

• in replacement of images

• as filter matrices

### Jitter Operators

• In Jitter, mathematical operators can be applied to matrices:

• This allows to generate important functions like thresholding!

### Jitter Operators

• For multi-band images, the operator can be applied to each image band separately:

### Connection to the outside world

• Additional programs can be developped for Jitter and Eyesweb.

• Possible in Java and C/C++

• Eyesweb allows TCP/IP interfacing (e.g. network cameras, process communication)

### Things to remember: Why you were here today!

• Jitter and Eyesweb base everything on Matrices

• Intuitive to use

• They process video data

• Jitter and Eyesweb are easy to use and are the basic systems to use for your project.

Info for Jitter: www.cycling74.com

Info for Eyesweb: www.eyesweb.org

www.media.aau.dk/~vok/lectures/ap1_11_05/ap11.html

### Finally:

• Questions?

• Exercises under http://media.aau.dk/~vok/lectures/ap1_11_05/ex11.pdf