detect audio data peaks using waveform image (not using web audio)

I was reading G. Skinner's take on using an image to detect volume peaks in order to create a custom visualizer display for audio and was wondering If anyone ever tried it using waveform images( like from soundcloud) to detect the peaks( volume/ amplitude/ frequency or whatever the term is) from an audio file. I want to use this as an alternative to using the Web Audio API which is a bit more tedious if you ask me and not supported in older devices( android 4.0).

Is there a way to process the colour data from a waveform image that can use to simulate such tasks?