John Curl's Blowtorch preamplifier part II

Status
Not open for further replies.
Photo and video storage are quite different. They are more like MP3 than CD, with lossy compression. All you ever get with most JPEG is a rough approximation to the original scene - good enough to fool the eye most of the time.

I learnt a bit about picture data compression a few years ago. One of the tricks used is to look for part of a picture which looks a bit like another part of the picture when modified (e.g. rotated, stretched, squeezed). Store one of these, and then use it (suitably modified) to stand in for the other one too. In some parts, don't store the picture but store its Fourier transform instead - with higher coefficients set to zero. The net result is a picture which looks very like the original, yet almost every pixel may have a different value from the original.

CD aims to reproduce the original signal. Pictures do not, so don't try to carry across any 'intuition' as it will lead you serously astray. Instead, learn about digital techniques.
 
Photo and video storage are quite different. They are more like MP3 than CD, with lossy compression. All you ever get with most JPEG is a rough approximation to the original scene - good enough to fool the eye most of the time.

I learnt a bit about picture data compression a few years ago. One of the tricks used is to look for part of a picture which looks a bit like another part of the picture when modified (e.g. rotated, stretched, squeezed). Store one of these, and then use it (suitably modified) to stand in for the other one too. In some parts, don't store the picture but store its Fourier transform instead - with higher coefficients set to zero. The net result is a picture which looks very like the original, yet almost every pixel may have a different value from the original.

CD aims to reproduce the original signal. Pictures do not, so don't try to carry across any 'intuition' as it will lead you serously astray. Instead, learn about digital techniques.

I shoot RAW
:)


Of course the 30-40mb files take up some space (lossless compressed, otherwise they would be 70mb!!!!!) but you have the quality, a photographic equivalent to FLAC.
 
Last edited:
Science often progresses by observing something that is not expected, and then conceiving an explanation.

And then isolating and ... testing your explanation ... and once you're onto something you've got an hypothesis and then ... then, you go back and forth a few times you've got yourself a, a ... a theory! :smirk:

Yes I know, my B.A. is in Phil of Sci.
 
Last edited:
And then isolating and ... testing your hypothesis, and once you're onto something and go back and forth a few times you've got yourself a, a ... a theory! :smirk:

Yes I know, my B.A. is in Phil of Sci.

Sure, but true fundamental theories are rare. Most of what we call theories are actually effective theories, something which works, but will be superseded at some point by yet another effective theory, like Newton - Einstein.
 
Since I'm not an EE, I can't make any sense out of why you keep repeating that mantra.

The only thing that matters, the ONLY thing, is the electrical output of the player- the rest of the stereo doesn't look at photodiode pickup. And the electronics and firmware (let's be clear about that distinction) in fact DO "do it all." It's a very robust system.
 
Status
Not open for further replies.