Gaborator reference: render.h

Spectrogram Rendering with Power-of-Two Scaling

template <class OI, class T>
void render_p2scale(const analyzer<T> &a,
                    const coefs<T> &c,
                    int64_t xorigin, int64_t yorigin,
                    int64_t xi0, int64_t xi1, int xe,
                    int64_t yi0, int64_t yi1, int ye,
                    OI output);

Render a rectangular array of pixel values representing signal amplitudes in time-frequency space, optionally scaling up or down by powers of two.

a

The spectrum analyzer that produced the coefficients c

c

A set of spectrogram coefficients to render

xorigin

The point in time corresponding to pixel X coordinate 0, in samples

yorigin

The band number of the frequency band corresponding to pixel Y coordinate 0

xi0

The X coordinate of the first pixel to render

xi1

The X coordinate one past the last pixel to render

xe

The horizontal scaling exponent. One horizontal pixel corresponds to 2^xe signal samples.

yi0

The Y coordinate of the first pixel to render

yi1

The Y coordinate one past the last pixel to render

ye

The vertical scaling exponent. One vertical pixel corresponds to 2^ye frequency bands.

output

A random access iterator through which the output pixel amplitude values will be written. This is typically a float *. A total of (xi1 - xi0) * (yi1 - yi0)) values will be written.

Utility Functions

template <class T>
unsigned int float2pixel_8bit(T amp);

Convert a normalized amplitude value to a 8-bit greyscale pixel value.

amp

A floating point value representing a signal amplitude, nominally ranging from 0 to 1

Returns an pixel value ranging from 0 to 255 (inclusive), using an approximation of the sRGB gamma.