Direction-invariant binary pattern-encoded descriptor for texture classification and retrieval

Abstract

Texture feature captures the structural arrangement details of pixels present in a given image. The local binary pattern (LBP) and its modified versions have been used to extract discriminant information about the structural arrangement. A unique textural representation obtained from LBP and its modified versions are affected by rotating the structural arrangement of the pixels available in a particular region. The weight of the binary values obtained from the LBP and its modified versions are constant. The structural arrangement of the local region is effectively determined from the direction-oriented edge information [i.e., local directional pattern (LDP)]. The LDP is also nonrobust toward the structural arrangement changes in the local region. We give a direction-invariant binary pattern to represent the texture details available in a particular location by encoding edge response along with the LBP of that region. The direction-invariant property is derived from the weight of the edge response available in a particular region. The edge response around each local region of the image is captured using the compass edge detector. It detects the edge details from eight directions. The process of encoding eight direction edge responses along with a binary pattern obtained from the center pixel difference gives a more robust texture descriptor than the other rotation-invariant descriptors used in texture feature extraction. The proposed descriptor is tested over five standard databases, namely Brodatz, color Brodatz, KTH-TIPS2b, FTVL, and free photo. The performance of the proposed rotation-invariant texture feature is more effective than the existing rotation-invariant local texture feature representations involved in the image classification and retrieval experiments.