Progress with Slit Scan

I have been battling long and hard with Quartz Composer to develop Slit Scan functionality that I can truly call my own. Although there are various demos, examples and plugins that achieve some of what I want to experiment with  – one of the learning objectives I have set myself for this module is to get up to speed with Quartz Composer in order to evaluate it as a composition/performance platform for future work. Quartz Composer is a modular, mainly visual authoring environment where core ‘modules’ are customised and joined together via ‘noodles’ to create more complex outcomes. For some reason the whole visual composition paradigm has presented me with particular problems as someone who is used to programming motion graphics and interactivity using code and in particular – Object Oriented Programming techniques.

I finally made my break through this week and have managed to build a couple of Slit Scan examples from the ground up. At the moment there is no particular optimisation employed and that is something I will look at before going much further.

Below is a screen grab of the functionality I have developed in Quartz Composer.

In the last post I mentioned the spider footage that I shot using a macro lens. Both Slit Scan examples use this footage in slightly different ways.

The first slit scan effect is created by placing evenly spaced ‘strips’ of delayed video on top of the source video playing back as normal. The overlayed strips are progressively less delayed from left to right – the left-most strip being the most delayed, the right-most strip being the least delayed. The diagram below illustrates this ‘delayed-lattice’ arrangement.

The second version has a similar arrangement but there are less slices and they are not the full height of the video frame. Additionally, the slices are fed through an image filter which makes them look like they are pencil drawn. The following diagram illustrates this ‘partial pencil lattice’ arrangement.

Both clips are a starting point. The next step (after optimisation to improve framerate) will be to use some simple MIDI cues probably generated by percussive sounds to dynamically trigger slit scan effects.

Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s