The computation of immediate texture discrimination involves finding boundaries between regions of differing texture. Various textures are examined to investigate the factors determining discrimination in the limited domain of line-and-point images. Two operators embodying necessary properties are proposed: length and orientation of actual lines and of local virtual lines between terminators. It is conjectured that these are sufficient as well. Relations between this theory and those of Julesz and of Marr are discussed. Supporting psychological evidence is introduced and an implementation strategy outlined.
