Posts about video quality metrics

Lesson of the Week: Why BD-Rate is a Poor Predictor of Real-World Bandwidth Savings

BD-Rate computations are a valuable metric when comparing theoretical codec performance. But just because they prove that HEVC is 40% more efficient than H.264 doesn’t mean that you’ll save 40% of your bandwidth if you switch to HEVC. This 6-minute video lesson explains why and suggests a better alternative for estimating real-world benefits. I include…

Analyzing Video Quality

This week’s lesson is an updated lesson for my course, Computing and Using Video Quality Metrics: A Course for Encoding Professionals. The agenda is shown in the YouTube frame. The lesson starts with an overview of rate-distortion curves and BD-Rate functions, what they are, and how you create them. Then I get into a pet…

Netflix Addresses VMAF Hackability with New Model

TL/DR: Netflix updates VMAF to include a new model that reverses out the effects of techniques like sharpening, contrasting, and histogram equalization.  As I reported in VMAF is Hackable: What Now?, you can increase VMAF scores via simple image enhancement techniques like sharpening, contrasting, and histogram equalization, which, when applied inappropriately, may not actually improve…

Five Star Review for Video Quality Metrics Course

Happy to report a five-star review for my course, Computing and Using Video Quality Metrics: A Course for Encoding Professionals. As far as I know, it’s the only course available that teaches how to compute and use metrics like VMAF, PSNR, SSIMPLUS, and SSIM, including how to create rate-distortion curves and BD-Rate comparisons. The review…