The field steerable mirror (FSM) Infrared camera system used in Persistent Surveillance Systems provides wide
area coverage using smaller number of cameras. The mirror locations float in a-priori known manner through the
field of view and is supposed to be stitched together using image features. This is because the platform motion
between mirror positions makes it difficult to exploit a-prior knowledge of the mirror positions. The mosaic
generation mechanism developed at ITT Exelis utilizes a calibration step which uses elementary shapes that are
joined continuously to create complex topologies that capture platform movement. This shape topology process
can be extended to other platforms and systems. This paper presents the process by which the meta-data is used
in the calibration step that will ultimately allow for real-time Infrared image mosaic generation. By using the
geographic coordinates, found in the image meta-data, we are able to estimate the amount of overlap between
any two images to be stitched, preventing the need for unnecessary and expensive image feature extraction and
matching. This is achieved by using a polygon clipping approach to determine the vertex coordinates of the
captured images in order to estimate overlap and disconnection in the field of view.
KEYWORDS: Point spread functions, Statistical analysis, Satellites, Interference (communication), Wavefronts, 3D modeling, Antennas, Signal detection, Situational awareness sensors, Correlation function
In this publication we propose an RF-based space situational awareness (SSA) system that provides proximity
sensing and hazardous space weather sensing. In our approach we use wideband antennas to transmit an outgoing
pulse and in return utilize the beam forming capability to detect the incoming wavefront from potential scattering
points for proximity sensing. Similarly we simultaneously send and receive from an antenna pair and characterize
the communication channel to ascertain the amount of ambient disruption to determine presence of hazardous
space weather. We leverage characteristics of space debris which appear as rough pieces of metal with a large
number of reflectors. Power consumption and detectability of small debris will certainly place a severe limitation
on our approach to which we intend to leverage our multi-source capability to provide sufficient signal power
for small object detectability. Several space phenomena involve charged particle streams with known plasma
frequencies within our RF bandwidth which in turn results in a disruption of communication channels. We
model these characteristics in our baseline calculation and indicate the presence of space weather when the
baseline deviates from our normal operation. We can then utilize this to place the space asset in a hardened
state to minimize damage all within sub-second response time.
One difficulty with using text from digital video for indexing and retrieval is that video images are often in low resolution and poor quality, and as a result, the text can not be recognized adequately by most commercial OCR software. Text image enhancement is necessary to achieve reasonable OCR accuracy. Our enhancement consists of two main procedures, resolution enhancement based on Shannon interpolation and text separation from complex image background. Experiments show our enhancement approach improves OCR accuracy considerably.
In this paper we present results of work done on large image browsing. Advances in compression and transmission have allowed efficient usage of storage and transmission resources; however, much work needs to be done in order to integrate such concepts in the processing and handling of data. One such problem is image browsing. Large images, in order of hundreds of Megabytes to Gigabytes, exist that not only strain storage resources of some computers but make transmission almost impossible for dialup networks or even some digital networks. By exploiting the fact that receiving nodes need to only view limited regions of the image, a data organization and handling mechanism is devised to serve the appropriate data in a timely fashion. A wavelet-based approach is pursued with desirable compression and progressive characteristics along with scalar and spatial access to pixel data.
In this paper, we first describe a structural compression technique which has been designed to facilitate document text image storage, retrieval, and processing. This technique provides an efficient representation of textural images and lends itself to lossy compression, progressive transmission, direct access to sub-regions of the document and document processing in the compressed domain. We describe a data structure which can be used to efficiently store the compressed information, provide algorithms for creating and manipulating it, and present results of document processing on images compressed form the University of Washington database.