clojure2d.extra.signal — clojure2d 1.4.4

Image pixels as signal

Pixels as Signal

Pixels (Image) can be treated as signal. Conversion to signal is based on strategies of converting image to RAW and then converting to audio. It includes channel data layout and packing into integer, encoding, endianess, etc.

To convert Pixels to signal use pixels->signal function. To convert back use signal->pixels. signal->pixels requires target Pixels object to store result of conversion. Target is mutated then.

To filter Pixels directly (without explicit conversion to and from Signals) you can use [[filter-channels]] with effects-filter.

apply-effects-to-pixels clj

(apply-effects-to-pixels effects pixels)

(apply-effects-to-pixels effects reset pixels)

(apply-effects-to-pixels effects config config-back pixels)

(apply-effects-to-pixels effects config config-back reset pixels)

Apply effects directly to Pixels.

Provide configurations to properly convert Pixels to Signal and back. Optionally set reset value (reinit effects' state after reset samples).

If you prefer operating through [[filter-channels]] use [[effect-filter]].

effects-filter clj

(effects-filter effects)

(effects-filter effects reset)

(effects-filter effects config config-back)

(effects-filter effects config config-back reset)

Creates filter to process Pixels as Signal using [[filter-channels]].

Provide configurations to properly convert Pixels to Signal and back. Optionally set reset value (reinit effects' state after reset samples).

Filter operates on one channel at time and is defined to be used with [[filter-channels]]. If you want to operate on Pixels directly, use apply-effects-to-pixels.

pixels->signal clj

(pixels->signal p)

(pixels->signal p
                {:keys [planar? signed? little-endian? bits channels coding]
                 :or {planar? true
                      little-endian? true
                      bits 8
                      signed? false
                      channels [0 1 2]
                      coding :none}})

Convert Pixels to Signal for given specifications.

Specification for conversion is based on Audacity importing options and image to RAW conversions practices. Spec contains:

• planar? - layout of channels data, planar (true, default) or interleaved (false)
• signed? - channel data are encoded as signed (true, default) or unsigned (false) integer.
• little-endian? - for 16 and 24 bits pack channel data with little-endian order (true, default) or big-endian (false)
• bits - pack channel data in 8 (default), 16 or 24 bits.
• channels - list of channels to convert to signal, default [0 1 2] (for all you can use :all keyword).
• coding - encode signal with one of the encoders: :alaw, :alaw-rev, :ulaw, :ulaw-rev or :none (default).

Pixels can be restored from Signal with signal->pixels function.

signal->pixels clj

(signal->pixels sig target)

(signal->pixels sig
                target
                {:keys [planar? signed? little-endian? bits channels coding]
                 :or {planar? true
                      little-endian? true
                      bits 8
                      signed? false
                      channels [0 1 2]
                      coding :none}})

Convert Signal to Pixels storing result into target (mutating it!).

Specification is the same as in [[pixels-signal]] functions.