A method of providing a combination of video data (37) and metadata (34) includes obtaining a sequence (23) of images captured by a video camera (5). At least one signal (24) is extracted from the sequence (23) of images, wherein each extracted signal (24) characterizes local temporal variations in at least one of light intensity and color. At least one video compression technique is applied on image data of images from the sequence (23) to obtain compressed video data (37). The extracted signals (24) are extracted from images in a state prior to the application of the at least one compression technique to image data from those images. The compressed video data (37) is provided with metadata (34) for characterizing at least one process in a subject represented in at least part of the images, which process causes local temporal variations in at least one of color and intensity of light captured from the subject. The metadata (34) is at least based on at least one of the extracted signals (24).
