Search types are known as indexes in the eVe APIs. The four indexes are Eve.COLOR, Eve.SHAPE, Eve.TEXTURE, and Eve.REGION.
Color. This type of search matches the predominant colors in the source and target images. The more colors the images have in common, and the more similar the proportions of those colors, the higher the target images score.
Shape. This type of search uses the two-dimensional outlines of objects within the image as patterns to match in the target image. The more similar the shape, the higher the target images score.
Texture. A texture search identifies unique textures within the image, and then ranks the target images based on their similarity to that texture.
Object Region. Region searches are the most advanced search type. In an object region search, eVe identifies statistically similar parts of the image and groups them into a certain number of regions, or classes. You can then apply color, shape, or texture searches to the individual object regions.