dropzone_rejet_image_based_on_dimension.js

//Create dropzone instance with some attributes
var myDropzone = new Dropzone(document.body, { // Make the whole body a dropzone
	url: siteurl// Url to process images uploaded.
	thumbnailWidth: 80,
	thumbnailHeight: 80,
	parallelUploads: 20,
	previewTemplate: previewTemplate,
	autoQueue: true, // Queue all files selected. It need to upload image.
	previewsContainer: "#previews", // Define the container to display the previews.
	clickable: ".fileinput-button", // Define the element that should be used as click trigger to select files.
	acceptedFiles: ".jpeg, .jpg, .png, .JPEG, .JPG, .PNG", //Filter images based on image extension.
	
	init: function(){
		//Verify thumbnail version for each image selected
		this.on("thumbnail", function(file) {
			//Reject image if image width < MIN_WIDTH
			if (file.width < MIN_WIDTH) {
			file.rejectImages();
			} else {
			    file.acceptImages();
			}
		});
	},
	accept: function(file, done){
		file.acceptImages = function(){
			//Your process...
			done();
		};
	
		file.rejectImages = function(){
			//Your process...
		};
	}
});

test