Dream Recorder - Technologies

Dream Recorder

''You were spending your days with your mac,
now you can spend your nights with it as well..."

Having an innovative idea such as Dream Recorder is a first step. But bringing it to life requires a lot of technology and data processing. The osX framework offers the ideal technology more than any other platform. We brought the know-how and inventiveness. Dream Recorder has been designed and realised by professionals of the field of scientific instrumentation.

OsX Embeded Technologies: Interfacing a computer with humans requires a lot of technology. The Apple know-how in that field is still unbeaten. OsX was the ideal environment for developing such a project. For developers like us, Core Audio and Core Image are outstanding toolkits taking care of most data operations in an efficient manner. Just invent and forget about optimization... Indeed, keeping the processing power low, thus avoiding fan noise, while implementing complex real-time image and audio processing is a challenge.

Night Vision Processing: Dream Recorder uses an image processing algorithm that stems from professional astronomers, using large CCD for deep star fields observation. A CCD sensor yields intrisic perturbations called the dark current and read-out noise. This makes the images looking grainy in dark environments.

On successive iSight images, the noise pixels will be different as they are random. On the other hand, real information will be present each time. Dream Recorder analyses the correlation between pixel information, image after image, and filters the noise by calculating the statistical variance.

Moreover, the image motifs are spread above many pixel. Here again, neighbor pixels will keep the same contrast, giving an additional noise rejection criteria.

Dream Recorder typically takes 60 dark images and produces a rendered 3D model used for motion detection. This methods works only on static subjects, which is of course the case of a sleeping person. This would not be efficient when filming moving subjects.

Voice processing: Dream Recorder permanently analyses each sounds of the night. It recognizes them and makes the difference between a person talking and snoring.

When you tell about the dream you just had, the sound processing will automatically record your voice and log it for you, without even touching the keyboard. After some seconds of silence, Dream Recorder will switch back to survey mode.

In the fisrt version of Dream Recorder, snoring was not distinguished from voices. Our users had gigabytes of snoring logged on their hard disk... Today's versions can just skip snoring. The amount of snoring is logged for statistics, and some snoring whistles can also be emmited by Dream Recorder... even if this feature is more a kind of gadget, but appreciated by some of our user's partner.

The voice processing is done throught the analysis of sound spectrograms, using the Core Audio framework of osX. This spectrogram is these of a person snoring. It shows some repeting patterns, at the rithm of the sleeper's breath.