When assessing the quality of a render, most of us use the "looks OK to me" approach which is perfectly fine for our own stuff. However, when comparing quality across codecs, render settings, etc. a little more objectivity is desirable. A technique used in other threads (e.g. https://www.vegascreativesoftware.info/us/forum/cpu-render-vs-vce--114009/?page=1) has been to place the rendered content on a track above the original content and then set the compositing mode to Difference. While this is a definite improvement, it still doesn't offer an easy means of producing a summary estimate of overall render quality.
To this end, I have written a very simple app, Render Quality Metrics (RQM), which does a frame by frame comparison between the original and rendered footage, and produces two traditional measures of image quality: mean-squared-error (MSE) and the peak signal-to-noise ratio (PSNR). Here is a screenshot of the tool.
If anyone is interested, RQM, along with instructions for its use, may be downloaded here: https://tools4vegas.com/library/.
Many thanks to John Dennis and _JN who participated in the initial testing of this app. Hopefully, some of you may find the tool useful. Suggestions for improvement are welcome.