In general, a picture can represent a specific environment or scene only when the picture is seen from a unique viewing point. The determination of this unique point and of the distortions that occur when the picture is viewed from other points is crucial to all aspects of pictorial perception. To clarify the effects of the point of observation on pictorial space, the present paper discusses how the correct point may be calculated, provides a geometric analysis of the effects of altering the viewing point, and briefly reviews the effects of such alterations on space perception.
This paper proposes a novel invariant local descriptor, a combination of gradient histograms with contrast intensity (CGCI), for image matching and object recognition. Considering the different contributions of sub-regions inside a local interest region to an interest point, we divide the local interest region around the interest point into two main sub-regions: an inner region and a peripheral region. Then we describe the divided regions with gradient histogram information for the inner region and contrast intensity information for the peripheral region respectively. The contrast intensity information is defined as intensity difference between an interest point and other pixels in the local region. Our experimental results demonstrate that the proposed descriptor performs better than SIFT and its variants PCA-SIFT and SURF with various optical and geometric transformations. It also has better matching efficiency than SIFT and its variants PCA-SIFT and SURF, and has the potential to be used in a variety of realtime applications.
This work intends to analyze the validity of inserting the study of Geometric Transformations in Basic Education. It is based on the analysis, from the historical perspective, of the use of these transformations by man and the development of these concept by mathematicians. It intends to show that this subject can be used as an integrating content between the branches of mathematics in basic education to contextualize teaching of subjects in which students do not easily see a practical application.
Four‐Dimensional Materials: Induction of Four‐Dimensional Spatiotemporal Geometric Transformations in High Cell Density Tissues via Shape‐Changing Hydrogels (Adv. Funct. Mater. 24/2021)
