DitherPaint: a 1-bit, browser-based drawing application

DitherPaint is a browser-based art tool in the tradition of MacPaint and HyperCard. While it is purely concerned with black-and-white images, it offers a variety of tools for working with texture and animating patterns within the image.

DitherPaint’s “Pattern” palette is supplied with a collection of default patterns which apply to any drawing tool. Click on one of the smaller swatches to select it, and it will be shown in the larger “Preview” swatch at the top of the palette. Clicking in the Preview swatch allows you to alter the definition of the pattern everywhere it is used in your image- left click draws black and right click draws white. Most drawing operations will preserve knowledge of the pattern used to draw pixels on the canvas. Notable exceptions are cut, copy, paste, and the “Invert” operation.

Opening a black-on-white or black-on-transparent image will result in a canvas composed of pattern 1 and 0, respectively. A color or grayscale image will be processed with Bill Atkinson’s dithering algorithm to produce an image composed, again, of pattern 1 and 0. Pasting in image data from the system clipboard will apply the same import process.

Copying image data to the clipboard is performed in a best-effort fashion. Some applications may not handle this data properly, and some older browsers do not support the necessary features. If a fallback is necessary, DitherPaint can also read and write data URIs as text in the clipboard.

If the filename is changed to include a `.json` extension, saving from DitherPaint will export a JSON document containing the image’s dimensions, pixel data, patterns, and animation settings. The same format can be read from an existing file.

You can use the program now in your browser here and the help file is here.