Image → sound → waterfall

Print a picture on Spectroid

Advanced

Picture

Choose an image or drop one here — high contrast works best

Invert (dark subject on a bright field)

Lowest tone Left edge of the picture. 100 Hz

Highest tone Stay under half the sampling rate. 10000 Hz

Spacing Match Spectroid's frequency axis.

Waterfall width Real pixel width — screenshots are often downscaled.

Waterfall height Pixels top to bottom after you drag the divider.

Axis starts at Left edge of the plot.

Axis ends at Right edge of the plot.

Transform interval Only the values Spectroid offers. Longer means more tones and a longer clip.

Measured stretch Came out too tall? Set how many times too tall and the width is corrected. 1.00 ×

Set row time automatically

Time per row Must outlast one FFT window or rows smear. 60 ms

Sampling rate Set the same value in Spectroid.

FFT size Smaller reacts faster and shortens the clip.

Decimations Sharpen low frequencies sideways at the cost of vertical blur.

Estimate the blur Spectroid adds

Brightest pixel Level the whitest part plays at. -25 dB

Darkest pixel Widen the gap for more contrast. -75 dB

Contrast Pushes midtones toward black or white. 1.00

Play true silence for black

Transform interval This is the one that matters. It sets how tall the picture lands.50 ms
Frequency axis The tones are spaced to match a log axis.Logarithmic
Exponential smoothing Smoothing averages each line into the next and blurs downward.0 (min)
Audio source Keeps Android's noise suppression and auto gain from eating the image.Unprocessed
Sampling rate48000 Hz
FFT size4096
Decimations Keep on for pictures reaching below ~1 kHz; 0 removes the vertical band seams.5
Window function Low sidelobes stop bright tones bleeding sideways.Blackman-Harris

Then pinch-zoom until 100 Hz to 10 kHz fills the width, and play it loud enough to sit above the room.