Image segmentation of natural scenes constitutes a major problem in Machine Vision. This paper presents a new proposal for the image segmentation problem, which has been based on the integration of edge and region information. This approach begins by detecting the main contours of the scene, which are later used to guide a concurrent set of growing processes. A previous analysis of the seed pixels permits adjustment of the homogeneity criterion to the region's characteristics during the growing process. Since the high variability of regions representing outdoor scenes makes the classical homogeneity criteria useless, a new homogeneity criterion based on clustering analysis and convex hull construction is proposed. Experimental results have proven the reliability of the proposed approach.