Abstract: A method of and a device for forming an image of an irradiated object in which images are formed with different exposure levels and the differently exposed images are combined so as to form a single image. The device includes a source and an imaging device which is connected to the source in order to form the image, the imaging device being arranged to form images with different exposure levels and being provided with an image processor in which the differently exposed images are combined so as to form the single image. The device produces images of a quality which is comparable to that of images acquired by means of a device having a much larger dynamic range.

Abstract: An X-ray examination apparatus for generating an X-ray image of an object, wherein X-ray image generator includes a brightness control input, image processor coupled to the X-ray image generator in order to output a brightness control signal to the control input. The X-ray image generator is provided with an X-ray data output, the image processor is provided with an X-ray data input coupled to the X-ray data output, and the image processor is arranged as calculating system for calculating absorption properties of the object and for generating the brightness control signal in dependence on the absorption properties. Intelligent measuring field selection is now possible on the basis of calculating absorption properties of identifiable objects or parts of objects reproduced in the visible image. Image quality is improved because of brightness control based on more intelligently selected measuring fields.

Abstract: An x-ray examination apparatus is provided with an auxiliary light-detection system for performing brightness control of a visible image produced on the exit screen of the x-ray image intensifier. The auxiliary light-detection system includes a photosensor having a wide dynamic range and a photodetector having a multitude of photosensitive elements so as to provide spatial resolving power. In particular the photodetector is a charge-coupled device (CCD-detector) having an inherently limited dynamic range. Brightness-control, notably avoiding overexposure in certain regions, is carried out by assembling relevant pixel-values of parts of the image into a control signal. The sensitivity of the CCD-sensor is adjusted by employing of the signal of the photosensor and a sensitivity-control device. Therefore, the sensitivity of the light-detection system is made to match the dynamic range of images due to a collection of x-ray exposures.