Technical notes on the Spears & Munsil High-Definition Benchmark, Blu-ray Edition

Overview

We had several goals building these patterns:

•·         Build each pattern in the color space and format that made the most sense. For example, if the pattern is for evaluating YCbCr issues, we built the pattern in YCbCr space directly rather than creating it in RGB and converting. This necessitated building our own pattern generation code, as no existing image editing software works in YCbCr natively. Similarly, most of the patterns were generated directly in 4:2:0, which again can't be created natively by image editors.

•·         Use the very best algorithms and the highest precision. In most cases, the patterns were generated using 64-bit floating point values for each channel of each pixel, and then converted to 8-bit using special dithering algorithms to preserve dynamic range. Where we needed to anti-alias lines and curves (for example in the sharpness pattern) we oversampled each pixel (again, with custom-written software) by 256x or more to get the smoothest possible edges and contours.

•·         Build patterns with digital in mind from the beginning. For a long time, all the standard video patterns have been designed for the limitations of analog broadcast. Since our patterns were built using an all-digital signal path and will never be broadcast, we don't need to conform to FCC bandwidth limitations or roll off high frequencies to avoid causing problems for old CRT displays. All of our patterns are built to use the absolute highest bandwidth available to modern all-digital equipment.

We used the same philosophy for simple patterns as well as complex ones. Every pattern on the disc has something about it that makes it unique, even the basic patterns like PLUGE and Color Bars.