Sass/Compass image size functions written in JavaScript as a Rework plugin. Uses Imagesize to read an image's size and replaces directives in CSS with that size. Inspired by rework-imagesize and Compass Image Dimension Helpers.

var rework = require('rework');
var sass_images = require('rework-sass-images');

var css = rework(str)
  .use(sass_images('path/to/images/folder'))
  .toString();

Using the above JavaScript. This:

h1 {
  background: url('myimage.png');
  background-size: image-size('myimage.png');
  width: image-width('myimage.png');
  height: image-height('myimage.png');
  text-indent: 100%;
}

Will produce this CSS:

h1 {
  background: url('myimage.png');
  background-size: 518px 202px;
  width: 518px;
  height: 202px;
  text-indent: 100%;
}

Use special functions hidpi-image-width|height|size to insert dimesnions divided by 2 if the image filename contains @2x in it. For example, considering the [email protected] size is 640x480:

div {
  background-size: hidpi-image-size('[email protected]');
  width: hidpi-image-width('[email protected]');
  height: hidpi-image-height('[email protected]');
}

will produce:

div {
  background-size: 320px 240px;
  width: 320px;
  height: 240px;
}

Insert actual size of the image in px:

• image-width('path/to/image') -- inserts the width of the image in px;
• image-height('path/to/image') -- inserts the height of the image in px;
• image-size('path/to/image') -- inserts the width AND the height of the image separated by white-space;

Insert image dimensions divided by 2 only if filename contains @2x in it. Otherwise insert real dimensions:

• hidpi-image-width('path/to/image@2x') -- inserts the width of the image divided by 2 for HiDPI images in px;
• hidpi-image-height('path/to/image@2x') -- inserts the height of the image divided by 2 for HiDPI images in px;
• hidpi-image-size('path/to/image@2x') -- inserts the width AND the height of the image divided by 2 for HiDPI images separated by white-space;

MIT