I have been searching this for a while, While I got another great plugin- JWindowCrop
Also you can get plugin from the repository.
It is benefitial for the fact that the plugin is quite simple and you can easily modify it as per your needs.
Here is how I did it to match the crop area of facebook cover:
HTML:
<img id="target" class="crop" alt="" src="images/sample-cover.jpg" />
JavaScript:
$('.crop').jWindowCrop({
targetWidth: 851, //Width of facebook cover division
targetHeight: 315, //Height of cover division
loadingText: 'Your Cover is uploading....',
onChange: function(result) {
console.log("separation from left- "+result.cropX);
console.log("separation from top- "+result.cropY);
console.log("width- "+result.cropW);
console.log("Height- "+result.cropH);
}
});
You can modify the internal region if you are not satisfies with the plugin.
NOTE: Since the facebook cover is of width 851px only, the uploaded image and the cropper division must be of same width i.e 851px.
I have prepared a DEMO here
EDIT:
Just in case if you noticed the text "Drag to reposition" in the crop area(top-left side) while you drag the image inside cover, you can mention you own text by changing this line of plugin:
Line:34- base.$frame.append('<div class="jwc_controls" style="position:relative;display:'+(base.options.showControlsOnStart ? 'block' : 'none')+';"><span class="dragger">Drag to reposition</span></div>');
I could not got time to add an option in the plugin to do so.