Abstract: Arrangement for distributing head related transfer function filters. In the arrangement a user device sends a request for a head related transfer function filter to the service being used. The service verifies if the user of the device has a subscription for a head related transfer function filters in the service being used and retrieves a filter as a response to a positive verification result. The service may filter audio channels and transmit filtered audio further. In an alternative embodiment the service transmits the filter to the user device for filtering the audio.

Abstract: Arrangement for acquiring images for producing a head related transfer function filter is disclosed. In the arrangement the camera of a mobile phone or similar portable device is adjusted for the imaging. All acquired images are analyzed and only suitable images are sent further for producing the head related transfer filter. The arrangement is further configured to provide instructions to the user so that the whole head and other relevant body parts are sufficiently covered.

Abstract: When three-dimensional audio is produced by using headphones particular HRTF-filters are used the sound for left and right channels of the headphone. As the morphology of every ear is different, it is beneficial to have HRTF-filters particularly designed for the user of headphones. Such filters may be produced deriving ear geometry from a plurality of images taken with an ordinary camera, detecting necessary features from images and fitting said features to a model that has been produced from accurately scanned ears comprising representative values for different sizes and shapes. Taken images are sent to a server that performs the necessary computations and submits the data further or produces the requested filter.

Abstract: When three-dimensional audio is produced by using headphones particular HRTF-filters are used the sound for left and right channels of the headphone. As the morphology of every ear is different, it is beneficial to have HRTF-filters particularly designed for the user of headphones. Such filters may be produced deriving ear geometry from a plurality of images taken with an ordinary camera, detecting necessary features from images and fitting said features to a model that has been produced from accurately scanned ears comprising representative values for different sizes and shapes. Taken images are sent to a server that performs the necessary computations and submits the data further or produces the requested filter.