lib/url/imageurl.js
function(options) {
        var params = [],
            opts = options || {},
            transform = 'sharpen';

        if (opts.preset) {
            params.push('preset=' + opts.preset);
        }

        if (typeof opts.radius !== 'undefined') {
            params.push('radius=' + opts.radius);
        }

        if (typeof opts.sigma !== 'undefined') {
            params.push('sigma=' + opts.sigma);
        }

        if (typeof opts.gain !== 'undefined') {
            params.push('gain=' + opts.gain);
        }

        if (typeof opts.threshold !== 'undefined') {
            params.push('threshold=' + opts.threshold);
        }

        if (params.length) {
            transform += ':' + params.join(',');
        }

        return this.append(transform);
    }
function(options) {
        var params = [],
            opts = options || {},
            transform = 'sharpen';

        if (opts.preset) {
            params.push('preset=' + opts.preset);
        }

        if (typeof opts.radius !== 'undefined') {
            params.push('radius=' + opts.radius);
        }

        if (typeof opts.sigma !== 'undefined') {
            params.push('sigma=' + opts.sigma);
        }

        if (typeof opts.gain !== 'undefined') {
            params.push('gain=' + opts.gain);
        }

        if (typeof opts.threshold !== 'undefined') {
            params.push('threshold=' + opts.threshold);
        }

        if (params.length) {
            transform += ':' + params.join(',');
        }

        return this.append(transform);
    }
function ( options ) { var params = [ ] , opts = options || { } , transform = 'sharpen' ; if ( opts . preset ) { params . push ( 'preset=' + opts . preset ) ; } if ( typeof opts . radius !== 'undefined' ) { params . push ( 'radius=' + opts . radius ) ; } if ( typeof opts . sigma !== 'undefined' ) { params . push ( 'sigma=' + opts . sigma ) ; } if ( typeof opts . gain !== 'undefined' ) { params . push ( 'gain=' + opts . gain ) ; } if ( typeof opts . threshold !== 'undefined' ) { params . push ( 'threshold=' + opts . threshold ) ; } if ( params . length ) { transform += ':' + params . join ( ',' ) ; } return this . append ( transform ) ; }
Sharpen the image

@param  {Object} [options]
@param  {String} [options.preset]         Name of a defined preset to use
@param  {Number} [options.radius=2]       Radius of the Gaussian operator in pixels
@param  {Number} [options.sigma=1]        Standard deviation of the Gaussian, in pixels
@param  {Number} [options.gain=1]         Percentage of difference between original and blurred image
that is added back into the original
@param  {Number} [options.threshold=0.05] Threshold in pixels needed to apply the difference gain
@return {Imbo.ImageUrl}
Sharpen the image