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Effect of Noise on Image Compression
Pavlík, Jiří ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This thesis examines effect of different types of noise on performance of significant image compression formats. Three different types of noise are examined, Gaussian noise, Gaussian noise with bigger granularity and shot noise. Two older loosy image compression formats JPEG and JPEG 2000 are compared with newer format WebP. This examination is based on results of experiments with images, which are intentionally degraded by noise, then compressed to examined formats and compared with result of experiments for original images without noise. The effect of noise on performance of comparised formats is based on image quality metric SSIM. From results of experiments, Gaussian noise with bigger granularity seems to be the least distruptive from all types of noises. The other two types of noise have much more dwindling effect on quality of images.
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Web Browser for IP Cameras
Černý, Pavel ; Veigend, Petr (referee) ; Zbořil, František (advisor)
The aim of the work described in this thesis was to enable live video streaming from IP cameras to selected users, using simply a modern web browser with no need to install special client-side software. The solution was found by utilizing programs FFmpeg (for communication with camera and video conversion to WebM format), Stream-m (for distribution of the data received from FFmpeg to clients), and a newly-created web application built on the Spring framework, which was used to control the aforementioned programs, and also allows camera management and user authorization. The resulting system reduces the effort required for client nodes deployment and maintenance. Thanks to the image size downscaling, the system brings about a considerable reduction of data flow in the network caused by camera output, and minimizes the load on client computers.
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Comparison of Lossy Image Compression Formats
Koláček, Ladislav ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This bachelor thesis deals with comparing of lossy image compression formats. The chapters describe principles of image compression and lossy formats themselves. Specifically the lossy formats JPEG, JPEG 2000, JPEG XR and WebP. The thesis includes theoretical comparison of the formats mentioned above, along with the methods used for measuring image quality. The practical part contains the results of the quality measurements of each format and description of design together with implementation of the tutorial.
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Modern compression formats of digital image
Eder, Radek ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
This bachelor thesis deals with the problems of digital image compression. There are described basic color models RGB and YCbCr and conversion between them. Described are currently used codecs for digital images. JPEG compression format is discussed in more detail, which currently is still the most widely used format for digital photos. Described is a process of digitizing the image using the JPEG standard, which includes sampling, quantization and coding. Described are also formats JPEG2000, PNG and WebP. End of chapter are described methods for subjective and objective evaluation of the quality of digital image compression. Among the subjective methods include Double Stimulus Impairment Scale (DSIS) and Double Stimulus Continuous Quality Scale (DSCQS), then the objective methods include Mean Squared Error (MSE), Peak Signal to Noise Ratio (PSNR) a Structural Similarity (SSIM). Application was created as part of the work that allows you to compress the source image to the selected formats. It also allows a qualitative evaluation of compression and store the results to the file.
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Comparison of Modern Lossy Image Compression Formats
Kalabza, Marek ; Klíma, Ondřej (referee) ; Bařina, David (advisor)
This thesis compares modern compression methods of digital images on given datasets in terms of quality. First part describes the principle of lossy compression and then compression of JPEG, Lepton, JPEG 2000, JPEG XR, WebP, BPG, HEIF, H.265 intra frame, H.264 intra frame and AV1. Second part focuses on testing, comparison of results and evaluation. It also describes quality metrics (PSNR, PSNR-YUV, SSIM), deals with possible artefacts created during compression and points out the behavior of formats after data corruption. Based on testing and measurement, it was found that the best compression format from the tested lossy image formats is the AV1 format, specifically on the high resolution dataset, the scanned document dataset, and the map dataset.
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Web Browser for IP Cameras
Černý, Pavel ; Veigend, Petr (referee) ; Zbořil, František (advisor)
The aim of the work described in this thesis was to enable live video streaming from IP cameras to selected users, using simply a modern web browser with no need to install special client-side software. The solution was found by utilizing programs FFmpeg (for communication with camera and video conversion to WebM format), Stream-m (for distribution of the data received from FFmpeg to clients), and a newly-created web application built on the Spring framework, which was used to control the aforementioned programs, and also allows camera management and user authorization. The resulting system reduces the effort required for client nodes deployment and maintenance. Thanks to the image size downscaling, the system brings about a considerable reduction of data flow in the network caused by camera output, and minimizes the load on client computers.
|
|
|
Comparison of Modern Lossy Image Compression Formats
Kalabza, Marek ; Klíma, Ondřej (referee) ; Bařina, David (advisor)
This thesis compares modern compression methods of digital images on given datasets in terms of quality. First part describes the principle of lossy compression and then compression of JPEG, Lepton, JPEG 2000, JPEG XR, WebP, BPG, HEIF, H.265 intra frame, H.264 intra frame and AV1. Second part focuses on testing, comparison of results and evaluation. It also describes quality metrics (PSNR, PSNR-YUV, SSIM), deals with possible artefacts created during compression and points out the behavior of formats after data corruption. Based on testing and measurement, it was found that the best compression format from the tested lossy image formats is the AV1 format, specifically on the high resolution dataset, the scanned document dataset, and the map dataset.
|
|
|
Modern compression formats of digital image
Eder, Radek ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
This bachelor thesis deals with the problems of digital image compression. There are described basic color models RGB and YCbCr and conversion between them. Described are currently used codecs for digital images. JPEG compression format is discussed in more detail, which currently is still the most widely used format for digital photos. Described is a process of digitizing the image using the JPEG standard, which includes sampling, quantization and coding. Described are also formats JPEG2000, PNG and WebP. End of chapter are described methods for subjective and objective evaluation of the quality of digital image compression. Among the subjective methods include Double Stimulus Impairment Scale (DSIS) and Double Stimulus Continuous Quality Scale (DSCQS), then the objective methods include Mean Squared Error (MSE), Peak Signal to Noise Ratio (PSNR) a Structural Similarity (SSIM). Application was created as part of the work that allows you to compress the source image to the selected formats. It also allows a qualitative evaluation of compression and store the results to the file.
|
|
|
Comparison of Lossy Image Compression Formats
Koláček, Ladislav ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This bachelor thesis deals with comparing of lossy image compression formats. The chapters describe principles of image compression and lossy formats themselves. Specifically the lossy formats JPEG, JPEG 2000, JPEG XR and WebP. The thesis includes theoretical comparison of the formats mentioned above, along with the methods used for measuring image quality. The practical part contains the results of the quality measurements of each format and description of design together with implementation of the tutorial.
|
|
|
Effect of Noise on Image Compression
Pavlík, Jiří ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This thesis examines effect of different types of noise on performance of significant image compression formats. Three different types of noise are examined, Gaussian noise, Gaussian noise with bigger granularity and shot noise. Two older loosy image compression formats JPEG and JPEG 2000 are compared with newer format WebP. This examination is based on results of experiments with images, which are intentionally degraded by noise, then compressed to examined formats and compared with result of experiments for original images without noise. The effect of noise on performance of comparised formats is based on image quality metric SSIM. From results of experiments, Gaussian noise with bigger granularity seems to be the least distruptive from all types of noises. The other two types of noise have much more dwindling effect on quality of images.
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