Medical imaging apparatus for the imaging of a light-sensitive object , such as biological tissue , the object having a spectral signature , the medical imaging apparatus comprising - a camera for capturing input images , the spectral signature of the object being represented in the input images by an input set of spectral bands , - an output interface for transmitting output images , the output images comprising an output set of spectral bands , - wherein the output set of spectral bands in the output images represents the spectral signature of the object in the visible light range wherein at least one input-only spectral band in the input set is replaced by at least one output-only spectral band in the output set , the medical imaging apparatus further comprising - a storage member , in which calibration data are stored for mapping the input set to the output set , and - an image processor for determining an intensity in the at least one output-only spectral band depending on the input set and the calibration data , characterized in that the storage member comprises representations of the spectral signatures of biological pigments (BP 1 to BP m ) for spectral fitting of the input set of an input image , wherein the medical imaging apparatus is adapted for at least one of the following: a) determining a local concentration of a biological pigment (BP 1 to BP m ) in the tissue from the input set of an input pixel in at least one of the input images and assigning the output set to an output pixel depending on the local concentration; or b) performing a spectral fitting to the input spectral signature , computing a tissue reference value from the spectral fitting, and retrieving, computing or determining the output spectral signature in dependence of the tissue reference value . - a camera for capturing input images , the spectral signature of the object being represented in the input images by an input set of spectral bands , - an output interface for transmitting output images , the output images comprising an output set of spectral bands , - wherein the output set of spectral bands in the output images represents the spectral signature of the object in the visible light range wherein at least one input-only spectral band in the input set is replaced by at least one output-only spectral band in the output set , the medical imaging apparatus further comprising - a storage member , in which calibration data are stored for mapping the input set to the output set , and - an image processor for determining an intensity in the at least one output-only spectral band depending on the input set and the calibration data , characterized in that the storage member comprises representations of the spectral signatures of biological pigments (BP 1 to BP m ) for spectral fitting of the input set of an input image , wherein the medical imaging apparatus is adapted for at least one of the following: a) determining a local concentration of a biological pigment (BP 1 to BP m ) in the tissue from the input set of an input pixel in at least one of the input images and assigning the output set to an output pixel depending on the local concentration; or b) performing a spectral fitting to the input spectral signature , computing a tissue reference value from the spectral fitting, and retrieving, computing or determining the output spectral signature in dependence of the tissue reference value . a) determining a local concentration of a biological pigment (BP 1 to BP m ) in the tissue from the input set of an input pixel in at least one of the input images and assigning the output set to an output pixel depending on the local concentration; or b) performing a spectral fitting to the input spectral signature , computing a tissue reference value from the spectral fitting, and retrieving, computing or determining the output spectral signature in dependence of the tissue reference value . <EOS>