The invention provides an improved shadow detection method based on a c3 space image, three aspects of
aerial image enhancement, multilateral weighted smooth denoising and
edge detection are improved,
contrast enhancement is carried out on the c3 space image by adopting logarithmic transformation, and the pixel value range of a low-gray region is greatly expanded so as to improve the accuracy of extraction of a shadow pixel in a shadow region; de-noising
processing is carried out on the image by adopting multilateral weighted filtering, and
image edge details can be kept while
image noise is removed; based on a Canny operator, a
diagonal direction is increased to improve a gradient amplitude calculation method, a critical domain is determined by adopting adaptive double-critical domain selection, and finally
edge detection is performed by adopting the double-critical domain; experiments prove that the shadow area can be successfully detected, interference of ground objects such as roofs and roads on detection results can be effectively weakened, and compared with an original
algorithm before improvement, the shadow detection accuracy is obviously improved.