Improved ROI Video Coding using Variable Gaussian Pre-Filters and Variance in Intensity

• In applications involving video over mobile phones or Internet, the limited quality depending on the transmission rate can be further improved by region-of-interest (ROI) coding. In this paper we present a preprocessing method using variable Gaussian filters controlled by a quality map indicating the distance to the ROI border. The border effects are reduced introducing a small improvement of the PSNR of the intensity component within the ROI after compression, compared to using only one low pass filter. With the compressed original sequence as a reference, the average PSNR was increased by 1.25 dB and 2.3 dB for 100 kbit/s and 150 kbit/s, respectively. A modified quality map is introduced using variance to exclude pixels, which are not visibly affected by the Gaussian filters, reducing computational complexity. Using less than 76% of the pixels gives no noticeable change in quality.

Ämnesord

NATURVETENSKAP  -- Data- och informationsvetenskap -- Datavetenskap (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences -- Computer Sciences (hsv//eng)

Nyckelord

ROI

Region-Of-Interest

Variable filters

Computer science

Datavetenskap

Publikations- och innehållstyp

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