/compass/005_compass/compass/node_modules/gm/lib/compare.js |
@@ -0,0 +1,120 @@ |
// compare |
|
var spawn = require('cross-spawn'); |
|
/** |
* Compare two images uses graphicsmagicks `compare` command. |
* |
* gm.compare(img1, img2, 0.4, function (err, equal, equality) { |
* if (err) return handle(err); |
* console.log('The images are equal: %s', equal); |
* console.log('There equality was %d', equality); |
* }); |
* |
* @param {String} orig Path to an image. |
* @param {String} compareTo Path to another image to compare to `orig`. |
* @param {Number|Object} [options] Options object or the amount of difference to tolerate before failing - defaults to 0.4 |
* @param {Function} cb(err, Boolean, equality, rawOutput) |
*/ |
|
module.exports = exports = function (proto) { |
function compare(orig, compareTo, options, cb) { |
|
var isImageMagick = this._options && this._options.imageMagick; |
var appPath = this._options && this._options.appPath || ''; |
var bin = isImageMagick |
? appPath + 'compare' |
: appPath + 'gm' |
var args = ['-metric', 'mse', orig, compareTo] |
if (!isImageMagick) { |
args.unshift('compare'); |
} |
var tolerance = 0.4; |
// outputting the diff image |
if (typeof options === 'object') { |
|
if (options.highlightColor && options.highlightColor.indexOf('"') < 0) { |
options.highlightColor = '"' + options.highlightColor + '"'; |
} |
|
if (options.file) { |
if (typeof options.file !== 'string') { |
throw new TypeError('The path for the diff output is invalid'); |
} |
// graphicsmagick defaults to red |
if (options.highlightColor) { |
args.push('-highlight-color'); |
args.push(options.highlightColor); |
} |
if (options.highlightStyle) { |
args.push('-highlight-style') |
args.push(options.highlightStyle) |
} |
// For IM, filename is the last argument. For GM it's `-file <filename>` |
if (!isImageMagick) { |
args.push('-file'); |
} |
args.push(options.file); |
} |
|
if (typeof options.tolerance != 'undefined') { |
if (typeof options.tolerance !== 'number') { |
throw new TypeError('The tolerance value should be a number'); |
} |
tolerance = options.tolerance; |
} |
} else { |
// For ImageMagick diff file is required but we don't care about it, so null it out |
if (isImageMagick) { |
args.push('null:'); |
} |
|
if (typeof options == 'function') { |
cb = options; // tolerance value not provided, flip the cb place |
} else { |
tolerance = options |
} |
} |
|
var proc = spawn(bin, args); |
var stdout = ''; |
var stderr = ''; |
proc.stdout.on('data',function(data) { stdout+=data }); |
proc.stderr.on('data',function(data) { stderr+=data }); |
proc.on('close', function (code) { |
// ImageMagick returns err code 2 if err, 0 if similar, 1 if dissimilar |
if (isImageMagick) { |
if (code === 0) { |
return cb(null, 0 <= tolerance, 0, stdout); |
} |
else if (code === 1) { |
err = null; |
stdout = stderr; |
} else { |
return cb(stderr); |
} |
} else { |
if(code !== 0) { |
return cb(stderr); |
} |
} |
// Since ImageMagick similar gives err code 0 and no stdout, there's really no matching |
// Otherwise, output format for IM is `12.00 (0.123)` and for GM it's `Total: 0.123` |
var regex = isImageMagick ? /\((\d+\.?[\d\-\+e]*)\)/m : /Total: (\d+\.?\d*)/m; |
var match = regex.exec(stdout); |
if (!match) { |
err = new Error('Unable to parse output.\nGot ' + stdout); |
return cb(err); |
} |
|
var equality = parseFloat(match[1]); |
cb(null, equality <= tolerance, equality, stdout, orig, compareTo); |
}); |
} |
|
if (proto) { |
proto.compare = compare; |
} |
return compare; |
}; |
|