Image Retrieval Using Gradient Operators

The images are described by its content like color, texture, and shape information present in them.In this paper novel image retrieval methods discussed based on shape features extracted using gradient operators like Robert, Sobel, Prewitt and Canny. Masking of Gradient operators takes place for continuing the discontinue edges. Morphological operations like erosion and dilation are used along with canny. The proposed image retrieval techniques are tested on generic image database images spread across different categories. Gradient operators features are extracted using Figure of Merit (FOM). The average precision and recall of all queries are computed and considered for performance analysis. The performance ranking of the masks for proposed image retrieval methods can be listed as Robert, Canny, Prewitt, and Sobel

Benchmarking Image Processing Algorithms for Unmanned Aerial System-Assisted Crack Detection in Concrete Structures

This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare dierent edge detectors. Edge detection was carried out by six filters in the spatial (Roberts, Prewitt, Sobel, and Laplacian of Gaussian) and frequency (Butterworth and Gaussian) domains. These algorithms were applied to fifty images each of defected and sound concrete. Performances of the six filters were compared in terms of accuracy, precision, minimum detectable crack width, computational time, and noise-to-signal ratio. In general, frequency domain techniques were slower than spatial domain methods because of the computational intensity of the Fourier and inverse Fourier transformations used to move between spatial and frequency domains. Frequency domain methods also produced noisier images than spatial domain methods. Crack detection in the spatial domain using the Laplacian of Gaussian filter proved to be the fastest, most accurate, and most precise method, and it resulted in the finest detectable crack width. The Laplacian of Gaussian filter in spatial domain is recommended for future applications of real-time crack detection using UAS

MelScan: An Android Application for Early Detection of Melanoma

Amongst the medical community, more focus was given on early detection of cancer, in particular melanoma, a type of skin cancer. Malignant melanoma was currently the leading source of death from skin diseases (Friedman et al., 2008). This project was aimed at making a mobile application that can be used by civilians in the rural areas to detect melanoma at its early stages, because it was difficult for them to get help from dermatologists in rural areas, as well as getting access to the proper equipment for melanoma detection. Due to time constraints, the scope of this study was narrowed to analyzing current image processing technology used in melanoma detection, especially on the Android mobile platform, developing an Android application that can use one of the image processing algorithms for melanoma detection, and to improve accuracy of melanoma detection, in particular during its early stages. To do this, a market research was carried to find out what were the available applications that were out there in the Google Playstore (also known as Google Market) that was also used for early detection of melanoma, before comparing the types of available image processing algorithms that was to be used during the development phase. Based on the findings, there were only 2 applications in the Google Market that was used for melanoma detection, and that the Prewitt operator makes for a good compromise between performance and complexity in developing the application. Overall, the application was developed successfully, and in the future, more functions would be added to make this application more marketable, such as cloud storage function and wearable technolog