Say It With Pictures

Sep 1, 2008 12:00 PM, By Dennis Miller

           
 

EIGHT PROGRAMS THAT CONVERT IMAGES TO MUSIC

BONUS MATERIAL
The UPIC System

Like MetaSynth, Coagula provides several folders full of filters with which you can alter new or existing files, and you can adjust how much a filter impacts the R, G, and B values of an image independently. You can also add your own filters — any BMP file will do. I posted a collection of files for this purpose at emusician.com, some of which produce rhythmic patterns when applied to any image (see Web Clip 3). Try running several filters in series to produce polyrhythmic effects, or apply a filter using 100 percent R and 0 percent G, then flip and mirror the filter and apply it again using 100 percent G and 0 percent R to get different types of processing on the left and right channels (see Web Clips 4 and 5 for an example).

Nicolas Fournel's AudioPaint 2.1 (Win, free)

AudioPaint is an intuitive program that packs a lot of power under a very simple interface. It is one of only two programs here that can generate a new sound using image data to control samples, and it has a batch-processing option that allows you to generate dozens of individual audio files from a folder full of graphic images. Though it doesn't offer any painting tools or filters for editing an image you import or create in the program, the three image generators it provides are very flexible and tend to produce pictures that result in very interesting audio without a lot of effort by the user.

FIG. 5: This image was created using AudioPaint’s Clouds of Points tool. Listen to Web Clip 6 to hear the sound this image generated.

Clouds of Points, for instance, is used to create a grainy image with dozens or even hundreds of small colored points, each of which will trigger a sonic event (see Fig. 5 and Web Clip 6). You can determine the overall height and width of the image, the number of Clouds it will contain, and the number of points that will make up each Cloud. You can also pick the shape for the individual Clouds or simply choose the Random option, which lets the program pick all the parameter values randomly. Equally innovative and potentially useful is the Random Web Picture feature, which grabs nine random images from the Internet, displays them as thumbnails, then lets you pick the one that looks the most interesting.

As with the other programs, you can import a preexisting graphics file, but Audio-Paint supports more formats than most of the rest of this group (JPEG, PNG, GIF, and BMP). Once an image is loaded, you can use the Audio Settings dialog box to pick the minimum and maximum frequencies for your new file (using hertz or note/octave increments) and choose between sine waves and a sample for the new sound's source. (Be sure to lower the maximum sampling rate if you're using samples, as the program does not filter out frequencies above the Nyquist frequency. Or perhaps you'd prefer to experiment with aliasing.) You can also determine which parameter of the image — whether Red, Green, Hue, Saturation, or Brightness — is used to generate the audio on the left and right channels independently.

AudioPaint may be a one-trick pony, but I was able to achieve very good results with fairly minimal effort, especially using the built-in generators. If you make it to Fournel's Web site, check out his other innovative freeware (all Windows only) to see if something else suits your fancy.

Image Line FL Studio 8 Express Edition (Win, $49)

FIG. 6: FL Studio’s BeepMap will convert an image to any number of partials you specify. All of its controls operate in real time.

FL Studio's BeepMap is a synthesis plug-in that first appeared in version 3.0 and that is available in all levels of the program, including the entry-level Express Edition. It uses a graphic image (BMP, JPEG, or PNG) to generate a set of frequencies and amplitudes that control partials using additive resynthesis. In the conversion process, BeepMap assigns values extracted from red pixels to the left channel's amplitude and from green pixels to the right channel's. Yellow results in an equal value for both channels, and you can choose whether the program will ignore blue pixels or use their values to scale each pixel's frequency. There are only a few parameters to modify; for example, you can use one of three types of scales for the partials (logarithmic, linear, and harmonics). You can also determine the number of partials that will be used by specifying the maximum height (in pixel increments) for the image (see Fig. 6).

BeepMap has a Length parameter that will adjust the duration of your new sound from a fraction of a second to around 20 seconds (there are no values or increments shown for Length), and you can set the sound to loop or play back as a one-shot. Like other FL Studio generators, all of BeepMap's controls can be modified in real time. You can drag a new graphics file directly onto a button containing a BeepMap generator, even while a sequence is playing back, and integrate it into the current project. You can also send the output of a BeepMap generator to any FL Studio effect; a healthy amount of filtering and reverb can be effective, depending on the source image you're using.