Subpixel rendering

About: Subpixel rendering is a research topic. Over the lifetime, 3885 publications have been published within this topic receiving 82789 citations.

Land Cover Change Mapping at the Subpixel Scale With Different Spatial-Resolution Remotely Sensed Imagery

Abstract: Extracting land cover change (LCC) information at the subpixel scale is important when coarse-resolution remotely sensed images are used for change detection. Although fraction images derived from soft-classification technologies can be used for subpixel LCC detection, the spatial distribution of changed subpixels within each coarse-resolution pixel cannot be provided. This letter presents a subpixel LCC mapping (SLCCM) algorithm, aiming to predict the spatial pattern of LCC at the subpixel scale between bitemporal images through comparing the former high-resolution land cover map and the latter fraction images derived from the coarse-resolution image. The resulting subpixel LCC map is determined by the spatial dependence principle and an LCC rule in each mixed pixel. The proposed algorithm was evaluated with simulated and real images, and the results showed the effectiveness of the proposed method for SLCCM.

Application of an improved subpixel registration algorithm on digital speckle correlation measurement

Abstract: Digital speckle correlation method (DSCM) has been widely used in experimental mechanics to obtain the surface deformation fields One of the challenges in practical applications is how to obtain the high accuracy with far less computation complexity To determine the subpixel registration of the DSCM, a high efficient gradient-based algorithm is developed in this paper The principle is described and four different modes of the algorithm are given Based on computer-simulated images, the optimal mode of the algorithm is verified through the comparison of computation time, optimal subset-region size and sensitivity of the four modes The influences of speckle-granule size and speckle-granule density on accuracy are studied and a quantitative estimation of the optimal speckle-granule size range is obtained As the applications of this method, the practical deformation measurements with the rigid body translation and rotation as well as an experiment on biomechanics are presented to certify the feasibility and the validity of the algorithm

Subpixel estimation of shifts directly in the Fourier domain

Abstract: In this paper, we establish the exact relationship between the continuous and the discrete phase difference of two shifted images, and show that their discrete phase difference is a two-dimensional sawtooth signal. Subpixel registration can, thus, be performed directly in the Fourier domain by counting the number of cycles of the phase difference matrix along each frequency axis. The subpixel portion is given by the noninteger fraction of the last cycle along each axis. The problem is formulated as an overdetermined homogeneous quadratic cost function under rank constraint for the phase difference, and the shape constraint for the filter that computes the group delay. The optimal tradeoff for imposing the constraints is determined using the method of generalized cross validation. Also, in order to robustify the solution, we assume a mixture model of inlying and outlying estimated shifts and truncate our quadratic cost function using expectation maximization.

Superresolution mapping using a Hopfield neural network with lidar data

Abstract: Superresolution mapping is a set of techniques to obtain a subpixel map from land cover proportion images produced by soft classification. Together with the information from the land cover proportion images, supplementary information at the subpixel level can be used to produce more detailed and accurate land cover maps. This research aims to use the elevation data from light detection and ranging (lidar) as an additional source of information for superresolution mapping using the Hopfield neural network (HNN). A new height function was added to the energy function of the HNN for superresolution mapping. The value of the height function was calculated for each subpixel of a certain class based on the Gaussian distribution. A set of simulated data was used to test the new technique. The results suggest that 0.8-m spatial resolution digital surface models can be combined with optical data at 4-m spatial resolution for superresolution mapping.

Display with pixel arrangement

Abstract: A display, including a substrate having a display area including first and second non-overlapping pixel groups and a gutter located between the first and second pixel groups, the gutter having a dimension in a first direction separating the first and second pixel groups, and each pixel group includes a plurality of pixels, each pixel having three or more differently colored sub-pixels; and wherein the pixel centers of the pixels in each pixel group are arranged in a regular two-dimensional array having one dimension parallel to the first direction, and wherein the pixels within a pixel group are separated by an inter-pixel separation in the first direction; and one or more electrical elements arranged within the gutter, each subpixel being connected to one of the one or more electrical elements, wherein the gutter dimension is greater than the inter-pixel separation, so that artifacts in a displayed image are reduced.