Converting frequencies to semitones/pitches on image files created by spectrograms

[Jedinhopy]

For this thread i take the spectrogram image that harmor creates out of this sound:

The original sound 100bpm.zip

Here is the preset:
http://s000.tinyupload.com/?file_id=896 ... 1240543881

Photoshop is unable to do these back and forth:
1. F -.log.- P.
2. P -.exp.- F.

Logarithms and Exponentiators.

Since i don't have the image pixel height convertor.
It turned out like this:



I expected to hear 3 note chords.

[Jedinhopy]

Up.

[xoxos]

i need to code one of these.

because the y axis in the image in every spectral analyser i have is totally whack. all of the "musical information" (within the range of human voice pitching) is crammed down in the bottom four pixels. imo that "linear to logarithmic" conversion should have been considered when creating the bmp, not when analysing it.

i'd just get angry and threaten to punch the developer when you go to their town so they know they can't be a punk


"thanks for that free, totally useless spectral analysis"!

[Jedinhopy]

i need to code one of these.

Thanks in advance.

[xoxos]

it's a bad strategy, really... i complain, hoping that a developer who already has done this will notice and go "oh, i can help.."

but other developers stopped paying attention to my manipulations some time ago i can't even get mystran to say anything nice any more. maybe the secret masonic police have moved in on both sides of him as well with their horrible brain projectors.

but it really is a sad thing... people say, "spectral analysis, we can do!""

but you turn the x axis on it's side, and they are all like "oh f**k off this has to be pixel by pixel..." like the god of dsp accuracy will smite them.



maybe the whole concept of image processing is too mysterious for audio dsp coders.

[xoxos]

basically, i want someone to use his brains and not put on an uptempo record every time i have to do a death dedication about a goddamn dog.


because otherwise, it gets ugly. "maybe i shove your musical information in four pixels, and see if you can retrieve it."

[Jedinhopy]

basically, i want someone to use his brains and not put on an uptempo record every time i have to do a death dedication about a goddamn dog.


because otherwise, it gets ugly. "maybe i shove your musical information in four pixels, and see if you can retrieve it."

For example try to fit a 10 minutes song with 10 octaves into a spectrogram that creates a BMP file with this fixed resolution:
128x48.

The width is 128 pixels and the height is 48 pixels.



10 minutes fits into 128 pixels on the width and 10 octaves fits into 48 rows on the height.

[Jedinhopy]

i need to code one of these.

The exe file.

[deastman]

basically, i want someone to use his brains and not put on an uptempo record every time i have to do a death dedication about a goddamn dog.


because otherwise, it gets ugly. "maybe i shove your musical information in four pixels, and see if you can retrieve it."

The letter U and the numeral two.

Could someone just hurry up already and port Matlab to VST?

[cytospur]

In Wolfram Mathematica 10 (available for free and usable for this sort of stuff on a Raspberry Pi2 running the Noobs distro):

wav = Import[
"C:\\Users\\Mark\\Downloads\\The original sound 100bpm\\The \
original sound 100bpm.wav"][[1, 1, 1]];
Colorize@ImageAdjust@
ImageTransformation[
Image[Reverse@
Transpose[
Abs[Fourier[#][[1 ;; 512]]] & /@
Partition[wav, 1024, 256]]], {#[[1]], #[[2]]^2} &]

This part: {#[[1]], #[[2]]^2} is an argument to the ImageTransformation function. Here, for illustrative purposes, I've kept the x-coordinates as they are and squared the y-coordinates to stretch it out.

It looks like this:

2D FFT.png

Edit: Sorry, I've probably missed it, but the idea is to import the wave in to Harmor and then do the analysis, right?

I'll do that now

[cytospur]

After going through Harmor (same transformation as above):

2D FFT Harmor.png

[deastman]

Okay, just so I'm actually clear on what the the issue here is, you want to take the logarithmic spectrogram out of Harmor, convert it to linear, mess with it in Photoshop, convert it to logarithmic, and bring it back into Harmor?

[Jedinhopy]

Okay, just so I'm actually clear on what the the issue here is, you want to take the logarithmic spectrogram out of Harmor, convert it to linear, mess with it in Photoshop, convert it to logarithmic, and bring it back into Harmor?

Yes.

[cytospur]

Okay, just so I'm actually clear on what the the issue here is, you want to take the logarithmic spectrogram out of Harmor, convert it to linear, mess with it in Photoshop, convert it to logarithmic, and bring it back into Harmor?

I get that, just wanted to show that the information for transformation is there. I don't have time to do this properly atm. I have a presentation to prepare for at work today, which incidentally is on image processing!

[Shabdahbriah]

Okay, just so I'm actually clear on what the the issue here is, you want to take the logarithmic spectrogram out of Harmor, convert it to linear, mess with it in Photoshop, convert it to logarithmic, and bring it back into Harmor?

I get that, just wanted to show that the information for transformation is there. I don't have time to do this properly atm. I have a presentation to prepare for at work today, which incidentally is on image processing!

I too, would put you at the top of my Christmas mailing list {if I had one} for coming up with something ('Windows friendly'), that accomplished this.