Modelling and Application of Contrast Enhancement of Visually Indistinct Colours Using Simple Single Band Image Capture Techniques

摘要

The concept of exposure density is used as a general model applied to the recording of two targets. This takes into account the spectral characteristics of all components of the imaging chain and is extended in the form of the System Exposure Response Difference (SERD) that is universally applicable to any imaging system. It provides a means for differentiation between two colours that appear identical and are recorded as being identical. Formulae are presented that model the capture and recording of two targets with both differing and with closely similar spectral reflectances. Excellent agreement is obtained between measured pixel differences and calculated (SERD) values. This method provides a means of modelling the required spectral band to be selected in advance of image capture such that the targets can be differentiated and work carried out in these laboratories on a variety of projects is summarised in this paper. Improvements in image contrast that have been modelled by this approach and applied to medical imaging and related area are included as a case studies. Advantages of this approach in comparison with multiband analysis or with post capture image enhancement techniques are discussed.