text: 
  var sharp = require('sharp')
  
  var simgr = require('../simgr')
  
  simgr.convertVIPS = function* (metadata, options) {
    var variant = options.variant
    var convert = sharp(metadata.path)
      .progressive()
      .rotate()
      .withoutEnlargement()
      .quality(variant.quality)
      .compressionLevel(9)
      .sequentialRead()
  
    var size = variant.size
    if (size) convert.resize(size.width, size.height).max()
  
    yield convert.toFile(options.out)
    options.signatures.push(yield* simgr.signature(options.out))
  }
  