• Home
  • Robust Feature
  • OpenAccess
    • List of Articles Robust Feature

      • Open Access Article

        1 - Online Signature Verification: a Robust Approach for Persian Signatures
        Mohamamd Esmaeel Yahyatabar Yasser  Baleghi Mohammad Reza Karami-Mollaei
        In this paper, the specific trait of Persian signatures is applied to signature verification. Efficient features, which can discriminate among Persian signatures, are investigated in this approach. Persian signatures, in comparison with other languages signatures, have More
        In this paper, the specific trait of Persian signatures is applied to signature verification. Efficient features, which can discriminate among Persian signatures, are investigated in this approach. Persian signatures, in comparison with other languages signatures, have more curvature and end in a specific style. Usually, Persian signatures have special characteristics, in terms of speed, acceleration and pen pressure, during drawing curves. An experiment has been designed to determine the function indicating the most robust features of Persian signatures. Results obtained from this experiment are then used in feature extraction stage. To improve the performance of verification, a combination of shape based and dynamic extracted features is applied to Persian signature verification. To classify these signatures, Support Vector Machine (SVM) is applied. The proposed method is examined on two common Persian datasets, the new proposed Persian dataset in this paper (Noshirvani Dynamic Signature Dataset) and an international dataset (SVC2004). For three Persian datasets EER value are equal to 3, 3.93, 4.79, while for SVC2004 the EER value is 4.43. Manuscript profile
      • Open Access Article

        2 - Improved Generic Object Retrieval In Large Scale Databases By SURF Descriptor
        Hassan Farsi Reza Nasiripour Sajad Mohammadzadeh
        Normally, the-state-of-the-art methods in field of object retrieval for large databases are achieved by training process. We propose a novel large-scale generic object retrieval which only uses a single query image and training-free. Current object retrieval methods req More
        Normally, the-state-of-the-art methods in field of object retrieval for large databases are achieved by training process. We propose a novel large-scale generic object retrieval which only uses a single query image and training-free. Current object retrieval methods require a part of image database for training to construct the classifier. This training can be supervised or unsupervised and semi-supervised. In the proposed method, the query image can be a typical real image of the object. The object is constructed based on Speeded Up Robust Features (SURF) points acquired from the image. Information of relative positions, scale and orientation between SURF points are calculated and constructed into the object model. Dynamic programming is used to try all possible combinations of SURF points for query and datasets images. The ability to match partial affine transformed object images comes from the robustness of SURF points and the flexibility of the model. Occlusion is handled by specifying the probability of a missing SURF point in the model. Experimental results show that this matching technique is robust under partial occlusion and rotation. The properties and performance of the proposed method are demonstrated on the large databases. The obtained results illustrate that the proposed method improves the efficiency, speeds up recovery and reduces the storage space. Manuscript profile
      • Open Access Article

        3 - Long-Term Spectral Pseudo-Entropy (LTSPE): A New Robust Feature for Speech Activity Detection
        Mohammad Rasoul  kahrizi Seyed jahanshah kabudian
        Speech detection systems are known as a type of audio classifier systems which are used to recognize, detect or mark parts of an audio signal including human speech. Applications of these types of systems include speech enhancement, noise cancellation, identification, r More
        Speech detection systems are known as a type of audio classifier systems which are used to recognize, detect or mark parts of an audio signal including human speech. Applications of these types of systems include speech enhancement, noise cancellation, identification, reducing the size of audio signals in communication and storage, and many other applications. Here, a novel robust feature named Long-Term Spectral Pseudo-Entropy (LTSPE) is proposed to detect speech and its purpose is to improve performance in combination with other features, increase accuracy and to have acceptable performance. To this end, the proposed method is compared to other new and well-known methods of this context in two different conditions, with uses a well-known speech enhancement algorithm to improve the quality of audio signals and without using speech enhancement algorithm. In this research, the MUSAN dataset has been used, which includes a large number of audio signals in the form of music, speech and noise. Also various known methods of machine learning have been used. As well as Criteria for measuring accuracy and error in this paper are the criteria for F-Score and Equal-Error Rate (EER) respectively. Experimental results on MUSAN dataset show that if our proposed feature LTSPE is combined with other features, the performance of the detector is improved. Moreover, this feature has higher accuracy and lower error compared to similar ones. Manuscript profile
      • Open Access Article

        4 - Farsi Font Detection using the Adaptive RKEM-SURF Algorithm
        Zahra Hossein-Nejad Hamed Agahi Azar Mahmoodzadeh
        Farsi font detection is considered as the first stage in the Farsi optical character recognition (FOCR) of scanned printed texts. To this aim, this paper proposes an improved version of the speeded-up robust features (SURF) algorithm, as the feature detector in the font More
        Farsi font detection is considered as the first stage in the Farsi optical character recognition (FOCR) of scanned printed texts. To this aim, this paper proposes an improved version of the speeded-up robust features (SURF) algorithm, as the feature detector in the font recognition process. The SURF algorithm suffers from creation of several redundant features during the detection phase. Thus, the presented version employs the redundant keypoint elimination method (RKEM) to enhance the matching performance of the SURF by reducing unnecessary keypoints. Although the performance of the RKEM is acceptable in this task, it exploits a fixed experimental threshold value which has a detrimental impact on the results. In this paper, an Adaptive RKEM is proposed for the SURF algorithm which considers image type and distortion, when adjusting the threshold value. Then, this improved version is applied to recognize Farsi fonts in texts. To do this, the proposed Adaptive RKEM-SURF detects the keypoints and then SURF is used as the descriptor for the features. Finally, the matching process is done using the nearest neighbor distance ratio. The proposed approach is compared with recently published algorithms for FOCR to confirm its superiority. This method has the capability to be generalized to other languages such as Arabic and English. Manuscript profile