his paper describes a technique to extract grain size information from areal images of sediment surfaces. An edge-detection algorithm is used to obtain the article boundaries and segment the image Ito individual grains. Further processing of the segmented image can result in detailed information about grain size, position, orientation and, depending on type of image, exposure. The images analysed in this paper were obtained by;er altimeter scans of sediment surfaces laboratory conditions. Further development of the method could harness photo-grammetric methods which are currently under development as a means of obtaining suitable images. Alternatively, carefully lit photographs have the potential to provide sufficient contrast at grain edges or the successful implementation of the image-processing technique. Therefore, is paper can be regarded as an interim ep towards the provision of an improved method for estimating surface sizes and composition, The results presented are sufficiently encouraging to make held trials, probably with other image types, an attractive possibility.