A Real Time Image Processing Subsystem: GEZGIN

In this study, a real-time image processing subsystem, GEZGIN, which is currently being developed for BILSAT-1, a 100kg class micro-satellite, is presented. BILSAT-1 is being constructed in accordance with a technology transfer agreement between TÜBITAK-BILTEN (Turkey) and SSTL (UK) and planned to be placed into a 650 km sunsynchronous orbit in Summer 2003. GEZGIN is one of the two Turkish R&D payloads to be hosted on BILSAT-1. One of the missions of BILSAT-1 is constructing a Digital Elevation Model of Turkey using both multi-spectral and panchromatic imagers. Due to limited down-link bandwidth and on-board storage capacity, employment of a realtime image compression scheme is highly advantageous for the mission. GEZGIN has evolved as an implementation to achieve image compression tasks that would lead to an efficient utilization of both the down-link and on-board storage. The image processing on GEZGIN includes capturing of 4-band multi-spectral images of size 2048x2048 8- bit pixels, compressing them simultaneously with the new industry standard JPEG2000 algorithm and forwarding the compressed multi-spectral image to Solid State Data Recorders (SSDR) of BILSAT-1 for storage and down-link transmission. The mission definition together with orbital parameters impose a 6.5 seconds constraint on real-time image compression. GEZGIN meets this constraint by exploiting the parallelism among image processing units and assigning compute intensive tasks to dedicated hardware. The proposed hardware also allows for full reconfigurability of all processing units

A real time, low latency, hardware implementation of the 2-D discrete wavelet transformation for streaming image applications

In this paper, we present a 2-D Discrete Wavelet Transformation (DWT) hardware for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n(1) x n(2) size image processed using (n(1)/k(1)) x (n(2)/k(2)) sized tiles the latency is equal to the time elapsed to accumulate a (1/k(1)) portion of one image. In addition, a (2/k(1)) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003

A real time, low latency, FPGA implementation of the 2-D discrete wavelet transformation for streaming image applications

In this paper, we present an architecture and a hardware implementation of the 2-D Discrete Wavelet Transformation (DWT) for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The architecture is especially suited for multi-spectral imager systems, such as on board an imaging satellite, however can be used in any application where time to next image constraints require real-time processing of multiple images. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n(1) x n(2) size image processed using (n(1)/k(1)) x (n(2)/k(2)) sized tiles the latency is equal to the time elapsed to accumulate a (1/k(1)) portion of one image. In addition, a (2/k(1)) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003

GEZGIN & GEZGIN-2: Adaptive Real-Time Image Processing Subsystems for Earth Observing Small Satellites

GEZGIN and GEZGIN-2 are real-time multispectral image processing subsystems developedfor BILSAT-1 and RASAT satellites respectively, the first two earth observing small satellites of Turkey. Main functionality of these subsystems is to compress in real-time multi-spectral images received concurrently from imagers, using JPEG2000 Image Compression algorithm. The compression features are controlled through user-supplied parameters uploaded in-orbit, so that the compression rate could be adapted to bandwidth, image quality and other mission requirements. GEZGIN employs both reconfigurable hardware and a DSP processor for image processing, where as the more advanced GEZGIN-2 contains full integration of the JPEG2000 processing path plus other image pre-processing features on reconfigurable hardware, hence offering increased performance and full re-configurability in orbit. Both systems demonstrate space-tailored architectures for implementing image processing functions where adaptability becomes the crucial issue determining robustness, flexibility and survivability of the system

GEZGIN-2: An advanced image processing subsystem for earth-observing small satellites

GEZGIN-2 is a real-time image processing subsystem, currently being developed for RASAT, the second small satellite to be launched by TUBITAK-BILTEN, in 2007. It is an advanced version of the GEZGIN payload, implementing JPEG 2000 image compression algorithm and currently flying on the BILSAT-1 satellite. The main enhancements in GEZGIN-2 are the integration of the full processing path of JPEG 2000 algorithm in a single Field Programmable Gate Array (FPGA) for increased processing performance and high speed data links complying with the ESA Spacewire standard, for data transfer at a rate of 100 Mbps. In addition to JPEG2000, GEZGIN-2 facilitates image pre-processing for cloud/sea detection and image/data encryption implemented on a daughter-board called GOLGE. As in GEZGIN, GEZGIN-2 allows for adjustment of compression ratio for different mission times by means of run-time supplied parameters and full reconfigurability in orbit

GEZGIN: A case study of a real-time image processing subsystem for micro-satellites

GEZGIN is a real-time image processing subsystem, developed as an R&D payload for BILSAT-1, the first earth observing micro-satellite of Turkey. The main functionality of GEZGIN is to compress in real-time multi-spectral images coming concurrently from the 4-band multi-spectral imager on BILSAT-1, using JPEG2000 Image Compression algorithm. The mission definition of BILSAT-1 imposes a 5.5 seconds interval constraint between two consecutive multi-spectral images with 20% overlap. GEZGIN fullfills this mission requirement by exploiting the parallelism among image processing units and assigning compute intensive tasks to dedicated hardware. The architecture of GEZGIN is highly integrated and fully reconfigurable allowing for the upgrade of all processing units in orbit. Hence it maintains flexibility and robustness against failures which are crucial properties for space applications. GEZGIN is built at low cost using completely "commercial-off-the-sheff" (COTS) components and having performed well in all the flight readiness tests, has been succesfully integrated on BILSAT-1. It is currently undergoing orbital tests