Evaluation of Lossy Compressed Mosaic for SPOT-6/7 Remote Sensing Data in SPACeMAP

SPACeMAP is a remote-sensing data portal system owned by LAPAN used to distribute mosaic data of Medium-Resolution to Very-High-Resolution for Provincial Governments. The frequently arising problem is that mosaic images have very large data size, especially for SPOT-6/7 mosaic images. The increasing number of data and users may affect the data loading process on the portal so that mosaic data compression can be considered. SPACeMAP has the Image Compressor feature using the Tile and Line algorithms with a compression ratio (target rate) recommended for optics (15 to 20). This study aims to determine the best algorithm and target rate to get compressed mosaic SPOT-6/7 imagery. The comparison method was done qualitatively through visual comparison and quantitatively by using Compression Ratio (CR), Bit per Pixel (BPP), and Peak Signal to Noise Ratio (PSNR). Results of the experiment show that, quantitatively, both Tile and Line algorithms give a different performance, depends on the zoom level and land cover characteristics. In terms of the qualitative result, the Tile algorithm gives better overall results compare to the Line algorithm. Quantitatively, both algorithms show good performance in the homogenous area. The target rate difference on the testing range does not affect process duration, nevertheless, the Line algorithm has a long process duration compare to the Tile algorithm. However, compression mosaics with lower or higher resolution remote sensing data may provide different results. Hence, this need be addressed on further studies.

THE DEITY AS A MOSAIC: IMAGES OF THE GOD XIPE TOTEC IN DIVINATORY CODICES FROM CENTRAL MESOAMERICA

In this article I argue that the graphic images of the gods in the divinatory codices are composed of signs of different semantic values which encode particular properties. All of them contribute to creating the identity of the god. However, these graphic elements are not only shared by different deities, but even differ between representations of the same god. Analyzing the graphic images of Xipe Totec, one of the best-studied deities and one of the oldest in Mesoamerica, I elaborate a hypothesis that the images of the gods in the divinatory codices were perceived by their authors as a mosaic of different properties, which at the same time were dynamic. Consequently, there was not even one “prototypical” representation of a single god, since possibly the identity of a god was defined precisely when composing his/her image with particular graphic signs, thus crystallizing some of his/her multiple properties, important at this precise moment.

Optimal JPEG Quantization Table Fusion by Optimizing Texture Mosaic Images and Predicting Textures

The JPEG standard allows the use of a customized quantization table; however, it is still challenging to find an optimal quantization table timely. This work aims to solve the dilemma of balancing computational cost and image-specific optimality by introducing a new concept of texture mosaic images. Instead of optimizing a single image or a collection of representative images, the conventional JPEG optimization techniques can be applied to the texture mosaic image to obtain an optimal quantization table for each texture category. We use the simulated annealing technique as an example to validate our framework. To effectively learn the visual features of textures, we use the ImageNet pre-trained MobileNetV2 model to train and predict the new image's texture distribution, then fuse optimal texture tables to come out with an image-specific optimal quantization table. Our experiment demonstrates around 30% size reduction with a slight decrease of FSIM quality but visually indistinguishable on the evaluation datasets. Moreover, our rate-distortion curve shows superior and competitive performance against other prior works under a high-quality setting. The proposed method, denoted as JQF, achieves per image optimality for JPEG encoding with less than one second additional timing cost.

Assessment of load bearing clay brick masonry for analyzing long-term durability through field measurement and visual review

This thesis examines a load bearing clay brick century home research house in Toronto (Canada) which has recently undergone the addition of polyurethane foam insulation on all interior sides of the exterior clay brick load bearing walls, increasing the insulating value in areas to RSI 7.9 W/m2K, on average. This study introduces and advances techniques to create high-resolution stitched mosaic images of the elevations to visually document the current physical condition of the brick. The critical saturation point was used to determine the capabilities of the clay brick masonry to resist freeze-thaw damage by way of frost dilatometry testing and compared to measurements taken by in-situ moisture content sensors in the brick masonry. This project also reveals how bricks expand and deteriorate in non-uniform manner during saturated three-dimensional dilatometry testing.

Assessment of load bearing clay brick masonry for analyzing long-term durability through field measurement and visual review

This thesis examines a load bearing clay brick century home research house in Toronto (Canada) which has recently undergone the addition of polyurethane foam insulation on all interior sides of the exterior clay brick load bearing walls, increasing the insulating value in areas to RSI 7.9 W/m2K, on average. This study introduces and advances techniques to create high-resolution stitched mosaic images of the elevations to visually document the current physical condition of the brick. The critical saturation point was used to determine the capabilities of the clay brick masonry to resist freeze-thaw damage by way of frost dilatometry testing and compared to measurements taken by in-situ moisture content sensors in the brick masonry. This project also reveals how bricks expand and deteriorate in non-uniform manner during saturated three-dimensional dilatometry testing.

SEAMLESS MOSAIC USING REMOVAL SUNGLINT TO SUPPORT A LARGE-SCALE MAPPING ACCELERATION

Mosaics of remote sensing images to support the acceleration of large-scale mapping are one of the steps in the data preparation process for dissemination to users, where generally users need seamless, mosaic images, especially on the land area. To produce a seamless mosaic image on the land area, it is sometimes constrained by the data that contains sunglints due to the direction of the recording that is opposite to the direction to the sun which causes the mosaic results to look not uniform in color on the land area. In this study, mosaics were carried out in the Pacitan area using Pleiades satellite data. From the existing problems, this study aims to compare the results of the mosaic image by removing sunglint compared to mosaic without removing sunglint. The results of this study indicate that the mosaic image by removing the sunglint produces a more seamless mosaic than the mosaic without removing the sunglint.

CRATER DETECTION USING TEXTURE FEATURE AND RANDOM PROJECTION DEPTH FUNCTION

In this paper, a novel automatic crater detection algorithm (CDA) based on traditional texture feature and random projection depth function has been proposed. By using traditional texture feature, mathematical morphology is used to identify crater initially. To further reduce the false detection rate, random projection depth function is used. For this purpose, firstly, gray level co-occurrence matrix and a novel grade level co-occurrence matrix are both used to further obtain the texture features of these candidate craters. Secondly, based on the above collected features, random projection depth function is used to refine the crater candidate detection results. LRO Narrow Angle Camera (NAC) mosaic images (1 m/pixel) and Wide-angle Camera (WAC) mosaic images (100 m/pixel) are used to test the accuracy of proposed method. The experimental results indicate our proposed method is robust to detect craters located in different terrains.