Transform video and audio to art.


What's New in iOS

Demo Videos



Spectra is a Mac and iOS app for creating computational art from video and audio.


What's New in iOS (top)


Previous Version 1.4.3, and Curret Version 1.4.4:


- FIXED: Saving background images to the Photos library now preserves transparency. In this way restoring a background from the photos library will restore the transparency, which is important for the mask mode of the Color pane.


- Improved Performance: Settings data is cached to handle the increased load from incorporating background images and waveform audio files. Most notably the presets table scrolls more smoothly, but other methods that use settings data is faster.


- Background Preview in Settings: The background image can be previewed from the user settings table. (Swipe on a row in iOS, right(control)-click on a row in macOS.)


- Open Settings Options: Opening settings is more discriminate - if current settings has background, but new settings do not then an alert is presented because the existence of a background could mean the spectra does not look as expected unless you change the background settings.


- Play Waveform Audio: The current waveform audio file can be played (if it exists; a waveform graphic only displays the audio samples, and its presence does not mean there is an audio file associated with it.) Select ‘Play Waveform Audio’ from the Audio menu. (Or on Mac use the ‘Play Waveform Audio’ button, and in iOS tap the waveform graphic)


- Apply Audio File Option: When opening settings with an audio file contained you have the option to ‘apply’ the audio file. This means that the file is read and stored as the current audio file for the waveform. This way if the settings are changed and saved a copy of the same audio can be included. (Audio is saved so that you can recall the audio by playing it from the user setting table.)


- Save Audio Option: Saving settings presents the option to NOT save the current waveform audio file. Saving the audio file is for two purposes:


1. So that you can recall the audio by playing it from the user setting table.

2. So that if you load setting with an audio file you apply it so it may be included when saving a modified version of the settings.


Previous Version 1.4.2:


- The current audio data, as well as the processed samples for graphics modulation, is stored in a Spectra settings file enabling playing of the audio within Spectra.


To play the audio: In the 'My Settings' pane of Presets swipe across a row to display the row actions menu: Play, Rename, Delete and select 'Play'.


If there is no audio to play you are told so - for example old settings files will not contain audio.


Note: When loading settings the audio data is not used to replace the current audio being used by Spectra. But since you can now play the audio that was the current audio at the time the settings were saved you can recall what it was.


- Ads have been removed to increase the space available to display controls panes.


Previous Version 1.4.1:


- Saving and restoration of Spectra settings supports background images and all background image options : show, fill and mask.


Note: when using an image as a mask white is transparent while other colors have varying amount of opacity.


- Settings tables modified for displaying white spectra (intended for use as background masks), and items labelled to indicate if contains a background image.


- When opening settings with a background 3 options are provided - ignore it, replace the current, or combine it with the current.


- Background can be masked by spectra (as well as spectra masked by background)


- 13 new audio ring tones


- Fix - saving background image to Photos library will preserve its transparency.


- Rather than set the dpiFactorSlider to 1 without warning alerts you after 3 warnings and only suggest lowering it.


- Background Image controls in Color pane to replace the menu with same functions, and similar to Mac version.


- Added new 'View' button to preview the background image with size displayed, and it uses same background texture as preview. Tap and hold the preview to open menu of color options.


- Media menu simplified: removed background management menu that has been superseded by new options in the color pane (for consistency with Mac version), and preview background color menu


- which can be set using “tap and hold” on preview.


Previous Updates:


- In the Size pane convenience button added to set the preview background color for contrast.

- Background image options for showing and masking are restored on app launch.


See demo video 'Mask Background Image'

See demo video 'Composite Spectra'

- In the Size pane an alert is presented if the resulting spectra will be greater than 12 megapixels.


- Background image can be used as a mask for the current spectra: white is transparent, black is opaque, intermediate colors are semi-transparent. This is illustrated in the screenshots.


See demo video 'Mask Background Image'


- The set of methods for managing the background image has been put into a separate background image menu available from the Media menu and Color pane.


- Background images can now be deleted in background image menu.


- Background images can now be set from Photos library in background image menu.


- Background images can be saved to Photos. (This is useful because a background image can be saved as a composite of a previous background and spectra.)


- A background image preview has been added to the Color pane (where the Background image is managed).


- A new color option in the color pane called ‘White’ intended to be used for creating background masks from a spectra.


- The preview background can be set to a texture to help view spectra using background masks that are white - available in Media menu, or by ‘tap and hold’ on preview itself.


- New builtin presets using the new Isosceles triangles option (in the Lines pane) have been added.


Features for generating new kinds of spectra graphics based on triangles, manage output metrics for improved print quality, setting background images and displaying a grid in the preview.




NEW - In the ‘Lines’ pane there is a new option to draw a line as an isosceles triangle, either solid or outlined. This option has an associated size parameter which is controlled using the adjacent size slider.


NEW - In the ‘Size’ pane there is a new option to draw a grid in the preview. You can either turn the grid off, or set it to a blue or gray color. The grid size matches the current ‘Width’ and ‘Height’ settings: the number of grid spaces matches each dimension.


NEW - In addition to the new grid option to act as spectra guides for printing to fit specific sizes, the dimension label in the ‘Size’ pane will display the current spectra size in inches to 2 decimal places for printing to 300 dpi.*


NEW - After a spectra is generated (i.e. saving) an alert is displayed which shows the actual dimensions of the spectra in inches to 2 decimal places for 300 dpi.*


*Note: the DPI of a spectra will vary based on available memory: if memory is limited the actual DPI may be less than the desired DPI. Use the ‘DPI Factor’ option in the ‘Size’ pane to extend the threshold for memory constraints if you need to print higher resolution than the default.


- Photos can be used for generating color palettes, as a supplemental method to using video for color.


See demo video 'Image For Color'


When using image for color extraction the image is subsampled for speed and the inherent spectra limit of 2048 colors. Hence not all the colors in an image will be realized in the generated palette for the spectra.


Live phots still have the option to use their video as the color source.


- Photos can be used for as background images that appear under the current Spectra.


- A menu item ‘Set Background Image From Spectra’ to set the background image to the current spectra. Enables composing multiple spectra into one.


See demo video 'Composite Spectra'


- A new menu item ‘Set Background Image From Video’ is a method to set the background image from the current player video frame.


- A new menu item ‘Show/Hide Background Image’ to hide or show the current background image.


NEW - In the ‘Color’ pane there is a new hide/show option for the current background image.


New: Video generation can be saved as a video. In File menu choose 'Save Spectra > Video'.



Demo Videos (top)


Composite Spectra

Mask Background Image

Image For Color

Composite Spectra (demos)


Mask Background Image (demos)


Image For Color (demos)


Description (top)



These are screenshots of Spectra running on an iPad.


Read this for an understanding how Spectra operates.


Click images to zoom.


Turn Video Into Art


In this sample, the graphics line length and width is modulated by the audio.


This is the 'Linear' spectra type.



Color From Video Frames


This sample illustrates the radial arc alternative spectra type.



Line & Arc Length From Sound Level


Start with one of the presets to get started. Then alter the various control values to acheive different affects.



Vary Controls For Countless Possibilities


Even changing the dimensions of the spectra will alter its appearance.



Save As PNG or Resolution Independent PDF


You can save the graphic as a PDF file to be printed at any resolution desired since it is 'resolution independent'.