An image processing method for segmenting an image, the method comprising: receiving first image; producing a second image from said first image, wherein said second image is a lower resolution representation of said first image; processing said first image with a first processing stage to produce a first feature map; processing said second image with a second processing stage to produce a second feature map; and combining the first feature map with the second feature map to produce a semantic segmented image; wherein the first processing stage comprises a first neural network comprising at least one separable convolution module configured to perform separable convolution and said second processing stage comprises a second neural network comprising at least one separable convolution module configured to perform separable convolution; the number of layers in the first neural network being smaller than the number of layers in the second neural network.