The invention provides an optical
remote sensing image ship target detection method fusing space-
frequency domain features. The method comprises the following steps: firstly, constructing an image feature map by utilizing a first-order gradient combination of a brightness feature map, a color feature map and brightness features of an image, carrying out non-overlapping partitioning on the image toobtain a plurality of image blocks, calculating a feature
covariance matrix of each image block, and calculating a feature value between the feature
covariance matrix of each image block and the feature
covariance matrix of the whole image, and obtaining a normalized feature value graph as a
spatial domain feature graph of the image; secondly, constructing
quaternion features of the image, performing
Fourier transform on the
quaternion features, setting a transformed amplitude spectrum as 1 to leave phase information, performing inverse
Fourier transform on the amplitude spectrum, and
smoothing an inverse transform result by using a
Gaussian filter to obtain a
frequency domain feature map; and finally, fusing the feature maps of the
spatial domain and the
frequency domain by using a
cellular automaton to obtain a final detection result. According to the method, the ship target can be rapidly and accurately detected from the
remote sensing image with complex sea surface
landform and cloud and
fog backgrounds, the serious
interference problem of the complex backgrounds on ship detection is solved, the ship detection effect under different complex backgrounds is good, and the application range is large.