I am writing an Android 1.5 application which starts just after boot-up. This is a Service
and should take a picture without preview. This app will log the ligh
it is really weird that camera on android platform can't stream video until it given valid preview surface. it seems that the architects of the platform was not thinking about 3rd party video streaming applications at all. even for augmented reality case the picture can be presented as some kind of visual substitution, not real time camera stream.
anyway, you can simply resize preview surface to 1x1 pixels and put it somewhere in the corner of the widget (visual element). please pay attention - resize preview surface, not camera frame size.
of course such trick does not eliminate unwanted data streaming (for preview) which consumes some system resources and battery.