Projecte llegit
Títol: Image data compression based of HPA and FAPEC
Estudiants que han llegit aquest projecte:
IUDICA, RICCARDO SALVATORE DARIO (data lectura: 05-03-2014)- Cerca aquest projecte a Bibliotècnica
IUDICA, RICCARDO SALVATORE DARIO (data lectura: 05-03-2014)Director/a: GARCÍA-BERRO MONTILLA, ENRIQUE
Departament: FIS
Títol: Image data compression based of HPA and FAPEC
Data inici oferta: 11-04-2013 Data finalització oferta: 11-12-2013
Estudis d'assignació del projecte:
| Tipus: Individual | |
| Lloc de realització: |
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| Nom del segon director/a (UPC): Jordi Portell Mora | |
| Departament 2n director/a: | |
| Paraules clau: | |
| Data compression, Images, FAPEC | |
| Descripció del contingut i pla d'activitats: | |
| Abstract: The Data Compression Group of the Institute for Space Studies of Catalonia (IEEC) has developed FAPEC, the Fully Adaptive Prediction Error Coder. FAPEC is a highly optimized adaptive entropy coder, which can be applied as a data compression solution for satellite payloads owing to its very quick and autonomous operation, furthermore with a high resiliency in front of data outliers. Additionally, the group has gained experience in image data compression using the Discrete Wavelet Transform from the CCSDS 122.0 standard for image data compression in space. The project proposed here consists in the implementation of a new pre-processing stage for image compression with FAPEC, either lossless or lossy (with different quality levels), using a new concept devised by the Group, called Hierarchical Pixels Averaging (HPA).
Main objectives: - Revise and document the definition of the HPA pre-processing stage, for lossless and lossy image compression - Implement a prototype of the HPA stage for FAPEC - Evaluate its performance (in ratios, PSNR for the lossy case, and speed) - Implement several improvements in the FAPEC core, specially for very low entropy levels Tasks: - Study the FAPEC compressor. - Study the DWT stage of the CCSDS 122.0 standard, just as a reference. - Study the preliminary HPA design provided by the Group. - Implement a preliminary prototype the HPA stage for the lossless case (accepting up to 28 bits per pixel preferably up to 64 bpp), evaluating the entropy achieved after the pre-processing, and the ratios obtained after applying FAPEC to the result. - Implement the decoding stage for decompression. - Extend the implementation for lossy compression (and decompression) with different quality levels, and evaluate its performance (including PSNR). - Revise and implement the improvements needed for the FAPEC core, specially for very low entropies. - Run a representative set of tests, covering significant cases for space-borne and ground-based systems, and evaluate ratios and performance. A data compression corpus is available. Outputs: - Data compression software (HPA stage, and revised/improved FAPEC). - Dataset(s) used for the tests and outputs. - Results of the tests performed on the software. - Document describing the HPA concept and its implementation, results obtained (compared to other systems such as CCSDS 122.0), and conclusions and recommendations. Interest of this project: - To implement a new data compression algorithm for images with a very low complexity and high compression performance, thus suitable for space missions (but also applicable on ground), trying to beat the current standards available. |
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| Overview (resum en anglès): | |
| We present the results of a new compression algorithm, Hierarchical Pixel Averaging (HPA), espcifically designed to compress images. Our results indicate that the compression ratios obtained with HPA are equivalent to those obtained using other standards, like JPEG. Specifically, we introduce the algorithm, its implementation and the several tests done so far on a standard set of images.
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