I am using HTML5 and fabric js for uploading multiple image in canvas. Right now i am uploading multiple image in canvas. But i want to find uploaded image width and height. I have seen one link Check image width and height before upload with Javascript
In this link not using file reader. But in my case using file reader.
var canvas = new fabric.Canvas('canvas');
document.getElementById('file').addEventListener("change",function (e) {
var file = e.target.files[0];
var reader = new FileReader();
console.log("reader " + reader);
reader.onload = function (f) {
var data = f.target.result;
fabric.Image.fromURL(data, function (img) {
var oImg = img.set({ width: 250, height: 200, angle: 0}).scale(0.9);
canvas.add(oImg).renderAll();
var a = canvas.setActiveObject(oImg);
var dataURL = canvas.toDataURL({format: 'png', quality: 0.8});
});
};
reader.readAsDataURL(file);
});
canvas{
border: 1px solid black;
}
<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.min.js"></script>
<input type="file" id="file">
<div style="">
<canvas id="canvas" width="450" height="450"></canvas>
</div>
You can create an img tag and get the dimensions from it.
document.getElementById('file').addEventListener("change",function (e) {
var file = e.target.files[0];
var reader = new FileReader();
var output = document.getElementById('output');
reader.onload = function (f) {
var data = f.target.result;
var img = document.createElement('img');
img.src = data;
img.onload = function() {
output.innerHTML = 'width: ' + img.width + '\n' +
'height: ' + img.height;
};
};
reader.readAsDataURL(file);
});
<input type="file" id="file"/>
<pre id="output"></pre>
#jcubic is right about using an <img> tag, (while there would be some ways to get this info without it) but he is absolutely wrong in how he gets the image's dimensions.
.clientWidth and .clientHeight will return the computed width of the <img> element. You don't care about it, since what you are drawing on your canvas is the image contained in the <img>, not the <img> element itself.
What you need then is .width and .height properties or .naturalWidth and .naturalHeight.
document.getElementById('file').addEventListener("change",function (e) {
var file = e.target.files[0];
var reader = new FileReader();
var output = document.getElementById('output');
reader.onload = function () {
var data = this.result;
var img = new Image();
img.src = data;
img.onload = function() {
output.innerHTML = 'width: ' + img.width + '\n' +
'height: ' + img.height;
};
};
reader.readAsDataURL(file);
});
<input type="file" id="file"/>
<pre id="output"></pre>
Related
I am facing problem for checking height and width for multiple images upload
there is no option for check height & width for image file using:
document.getElementById('id').files;
So I need help to check height & width of multiple uploaded images using JavaScript
//html code
<input type='file' name='images[]' id='image' multiple>
//javascript code
$("#image").change(function () {
var this_image = $(this);
var img = document.getElementById('image').files;
var img_len = img.length;
for(var i=0;i<img_len;i++)
{
var this_img = document.getElementById('image').files[i];
var reader = new FileReader();
//Read the contents of Image File.
reader.readAsDataURL(document.getElementById('image').files[i]);
reader.onload = function (e) {
//Initiate the JavaScript Image object.
var image = new Image();
//Set the Base64 string return from FileReader as source.
image.src = e.target.result;
//Validate the File Height and Width.
image.onload = function () {
var height = this.height;
var width = this.width;
console.log(height+"---"+width);
};
}
});
Function for getting image width & height from File object:
function getImageSize(file, callback) {
var reader = new FileReader();
reader.onload = function(e) {
var img = new Image();
img.onload = function(e2) {
callback(img.width, img.height);
}
img.src = e.target.result;
};
reader.readAsDataURL(file);
};
For example, if the file upload input has the id 'inputFile', the following code will print to the console the size of all its images:
var files = document.getElementById('inputFile').files;
for (var i = 0; i < files.length; i++) {
getImageSize(files[i], function(width, height) {
console.log('Image: Width = ' + width + ', height = ' + height);
});
}
Note: it won't necessarily print the images sizes as their order!
function changeFile() {
var preview = document.getElementById("previewDiv");
preview.style.backgroundImage = "";
var element = document.getElementById("ads_files");
var files = element.files;
var file = files[0];
console.log(file);
var reader = new FileReader();
reader.onload = loadFinished;
reader.readAsDataURL(file);
function loadFinished(event) {
var data = event.target.result;
preview.style.backgroundImage = 'url(' + data + ')';
}
}
#previewDiv {
border: 2px solid rgb(204, 204, 204);
width: 250px;
height: 200px;
background-size: 100% 100%;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="file" id="ads_files" name="file" onchange=changeFile() />
<div id="previewDiv">
</div>
The code above is to upload a picture and show it as the background of div. It works perfectly.
Now I wish to upload the picture with proper width and height. So I need to get the size of the upload picture (The other pictures won't be uploaded to server).
I've searched some solutions on internet. It seems that document.getElementById("ads_files").value may get the path of the file after the image is uploaded. Then use Image.src=document.getElementById("ads_files") to load the image and get the size with function of Image.
But the question is that the value is a fake path like c:\fakepath\10256530_503531203106865_63236440322903725_n.jpg (I'm using Mac!!!!). Of course the program won't work.
I bet the work can be done locally but I don't know how to do it.
Any good idea?
Here is how you retrieve the image dimensions, add these to your loadFinished() function
var image = new Image();
image.src = data;
image.onload = function() {
console.log(image.naturalWidth, image.naturalHeight);
}
Try It Once
function imgSize(){
var myImg = document.querySelector("#sky");
var realWidth = myImg.naturalWidth;
var realHeight = myImg.naturalHeight;
alert("Original width=" + realWidth + ", " + "Original height=" + realHeight);
}
<img src="http://files.codepedia.info/uploads/2015/08/getFileName_size.jpg" id="sky" width="250" alt="Cloudy Sky" contextmenu="skymenu">
<p><button type="button" onclick="imgSize();">Get Original Image Size</button></p>
May Be this can help you
function changeFile() {
var preview = document.getElementById("previewDiv");
preview.style.backgroundImage = "";
var element = document.getElementById("ads_files");
var files = element.files;
var file = files[0];
console.log(file);
/*Code here to show width on console*/
console.log($(element).width());
var reader = new FileReader();
reader.onload = loadFinished;
reader.readAsDataURL(file);
function loadFinished(event) {
var data = event.target.result;
preview.style.backgroundImage = 'url(' + data + ')';
}
}
Image is getting created in full original size, even last two arguments 150, 150 are height and width context.drawImage(img, 0, 0, 150, 150); in the code below:
function (file) { //uploaded files are always images
var reader = new FileReader(); //FileReader for uploading files from local stroge.
reader.onload = function () {
var links = document.createElement('a'); //link when image is clicked
var img = document.createElement('img');
img.src = reader.result; //src = url from uploaded file
img.className = 'images'; //css -> .images { margin-top: 30px; padding: 30px; }
img.onload = function () { //repaint image to 150 - 150 size with canvas, because setting width and height on image itself would just resize the image but I want to create new image with new size
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
context.drawImage(img, 0, 0, 150, 150) //draw image with canvas
}
links.href = reader.result; // url from local storage needed when image is clicked -
links.target = "_blank"; // open new blank page with original image
links.appendChild(img); // image is appended to <a>
document.body.appendChild(links); // <a> is appended to body, that body contains image thumbnail with a link linked to the image source
}
if (file) {
reader.readAsDataURL(file); // read uploaded files url
}
}
img.onload does not making any sense here. result is the same even when I remove it.
You are not drawing back the cropped image to your <img> tag... you will have to create two image Objects, let's call the first originalImage, and the second one croppedImage.
The one you will append to the document is croppedImageand originalImage will just stay in the cache.
When originalImage has loaded, you will paint it to a canvas, and then set croppedImage to the result of the canvas' toDataURL() method.
var read = function() {
var file = this.files[0];
var reader = new FileReader();
reader.onload = function() {
var links = document.createElement('a');
// this will be the appended image
var croppedImage = new Image();
// do your DOM stuff
croppedImage.className = 'images';
links.href = reader.result;
links.target = "_blank";
links.appendChild(croppedImage);
document.body.appendChild(links);
// create a buffer image object
var originalImage = new Image();
// set its load handler
originalImage.onload = function() {
// create a canvas
var canvas = document.createElement('canvas');
// set canvas width/height
canvas.width = canvas.height = 150;
var context = canvas.getContext('2d');
// draw the buffered image to the canvas at required dimension
context.drawImage(originalImage, 0, 0, 150, 150);
// set the appended to doc image's src to the result of the cropping operation
croppedImage.src = canvas.toDataURL();
}
originalImage.src = reader.result;
}
if (file) {
reader.readAsDataURL(file);
}
};
upload.onchange = read;
.images {
margin-top: 30px;
padding: 30px;
}
<input type="file" id="upload" />
You could also have used only a single image object, but this would have required to reset the onload event in the onload event, to avoid an infinite loop, which is a little bit less clear :
var read = function() {
var file = this.files[0];
var reader = new FileReader();
reader.onload = function() {
var links = document.createElement('a');
var img = new Image();
img.className = 'images';
links.href = reader.result;
links.target = "_blank";
links.appendChild(img);
document.body.appendChild(links);
img.onload = function() {
//reset the onload event so it does fire in a loop
img.onload = function(){return;};
var canvas = document.createElement('canvas');
canvas.width = canvas.height = 150;
var context = canvas.getContext('2d');
context.drawImage(this, 0, 0, 150, 150);
this.src = canvas.toDataURL();
}
img.src = reader.result;
}
if (file) {
reader.readAsDataURL(file);
}
};
upload.onchange = read;
.images {
margin-top: 30px;
padding: 30px;
}
<input type="file" id="upload" />
var reader = new FileReader();
reader.onload = function () {
var links = document.createElement('a');
var img = new Image();
img.src = reader.result;
img.className = 'images';
img.onload = function () {
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
context.drawImage(this, 0, 0, 150, 150);
this.src = canvas.toDataURL(); // convert the canvas back to the image
links.appendChild(this); // append the updated image to the document
}
links.href = reader.result;
links.target = "_blank";
document.body.appendChild(links);
}
if (file) {
reader.readAsDataURL(file); //reads the data as a URL
}
I can load an image into a canvas element and resize it, but I'm having trouble grabbing the resized image:
var logo = $(".logo"),
loader = $(".load"),
canvas = $(".holder"),
ctx = canvas[0].getContext("2d");
function displayPreview(file) {
var reader = new FileReader();
reader.onload = function(e) {
var img = new Image();
img.src = e.target.result;
img.onload = function() {
// x, y, width, height
ctx.drawImage(img, 0, 0, 128, 128);
var dataURL = canvas[0].toDataURL("image/png");
var logo = $(".logo");
var imgUrl = dataURL;
var imgz = $("<img>");
imgz.attr("src", imgUrl);
logo.html("");
logo.append(imgz);
};
};
reader.readAsDataURL(file);
}
into the download package function for jszip.
// Download Zip
$(".download").on("click", function(imgUrl) {
var zip = new JSZip();
zip.file("logo.png", imgUrl);
var content = zip.generate({type:"blob"});
// see FileSaver.js
saveAs(content, "test.zip");
});
Snippet:
var logo = $(".logo"),
loader = $(".load"),
canvas = $(".holder"),
ctx = canvas[0].getContext("2d");
function displayPreview(file) {
var reader = new FileReader();
reader.onload = function(e) {
var img = new Image();
img.src = e.target.result;
img.onload = function() {
// x, y, width, height
ctx.drawImage(img, 0, 0, 128, 128);
var dataURL = canvas[0].toDataURL("image/png");
var logo = $(".logo");
var imgUrl = dataURL;
var imgz = $("<img>");
imgz.attr("src", imgUrl);
logo.html("");
logo.append(imgz);
};
};
reader.readAsDataURL(file);
}
$(document).ready(function() {
loader.on("change", function(evt) {
var file = evt.target.files[0];
displayPreview(file);
var reader = new FileReader();
reader.onload = function(e) {
// Download Zip
$(".download").on("click", function(imgUrl) {
var zip = new JSZip();
zip.file("logo.png", imgUrl);
var content = zip.generate({type:"blob"});
// see FileSaver.js
saveAs(content, "test.zip");
});
return false;
};
reader.readAsArrayBuffer(file);
});
// Trigger Load Image
$(".trigload").click(function() {
$("input").trigger("click");
});
});
#import url("http://necolas.github.io/normalize.css/3.0.1/normalize.css");
.hide {
display: none;
}
.logo {
text-align: center;
}
.fill {
width: 100%;
}
.fr {
float: right;
}
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip/dist/jszip.min.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip-utils/dist/jszip-utils.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip/vendor/FileSaver.js"></script>
<input type="file" class="hide load">
<a class="trigload" href="javascript:void(0)">Load Image</a>
<a class="download fr" href="javascript:void(0)">Download</a>
<div class="logo"></div>
<div class="fill" align="center">
<canvas class="holder" width="128" height="128"></canvas>
</div>
In order to get JSZip to correctly save your dataURL to valid png file, it seems you need to add an object containing {base64: true}as third argument of the zip.file() method, and to remove the data:image/png;base64, from the dataURL.
Also, you were assigning the click event to the imgUrl variable. You may want to store it in a global variable, or check the $('.logo>img')[0].src or call once again canvas[0].toDataURL().
var logo = $(".logo"),
loader = $(".load"),
canvas = $(".holder"),
ctx = canvas[0].getContext("2d");
function displayPreview(file) {
var reader = new FileReader();
reader.onload = function(e) {
var img = new Image();
img.src = e.target.result;
img.onload = function() {
// x, y, width, height
ctx.drawImage(img, 0, 0, 128, 128);
var dataURL = canvas[0].toDataURL("image/png");
var logo = $(".logo");
var imgUrl = dataURL;
var imgz = $("<img>");
imgz.attr("src", imgUrl);
logo.html("");
logo.append(imgz);
};
};
reader.readAsDataURL(file);
}
$(document).ready(function() {
loader.on("change", function(evt) {
var file = evt.target.files[0];
displayPreview(file);
var reader = new FileReader();
reader.onload = function(e) {
// Download Zip
$(".download").on("click", function() {
var imgUrl = canvas[0].toDataURL();
var zip = new JSZip();
zip.file("logo.png", imgUrl.split('base64,')[1],{base64: true});
var content = zip.generate({type:"blob"});
// see FileSaver.js
saveAs(content, "test.zip");
});
return false;
};
reader.readAsArrayBuffer(file);
});
// Trigger Load Image
$(".trigload").click(function() {
$("input").trigger("click");
});
});
#import url("http://necolas.github.io/normalize.css/3.0.1/normalize.css");
.hide {
display: none;
}
.logo {
text-align: center;
}
.fill {
width: 100%;
}
.fr {
float: right;
}
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip/dist/jszip.min.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip-utils/dist/jszip-utils.js"></script>
<script type="text/javascript" src="http://stuk.github.io/jszip/vendor/FileSaver.js"></script>
<input type="file" class="hide load">
<a class="trigload" href="javascript:void(0)">Load Image</a>
<a class="download fr" href="javascript:void(0)">Download</a>
<div class="logo"></div>
<div class="fill" align="center">
<canvas class="holder" width="128" height="128"></canvas>
</div>
2022 Edit
JSZip now accepts Blobs as input directly, so it's better to convert your canvas to a Blob and pass this directly to JSZip. (As a fiddle because StackSnippets don't allow-downloads).
How can I get the file size, image height and width before upload to my website, with jQuery or JavaScript?
Multiple images upload with info data preview
Using HTML5 and the File API
Example using URL API
The images sources will be a URL representing the Blob object
<img src="blob:null/026cceb9-edr4-4281-babb-b56cbf759a3d">
const EL_browse = document.getElementById('browse');
const EL_preview = document.getElementById('preview');
const readImage = file => {
if ( !(/^image\/(png|jpe?g|gif)$/).test(file.type) )
return EL_preview.insertAdjacentHTML('beforeend', `Unsupported format ${file.type}: ${file.name}<br>`);
const img = new Image();
img.addEventListener('load', () => {
EL_preview.appendChild(img);
EL_preview.insertAdjacentHTML('beforeend', `<div>${file.name} ${img.width}×${img.height} ${file.type} ${Math.round(file.size/1024)}KB<div>`);
window.URL.revokeObjectURL(img.src); // Free some memory
});
img.src = window.URL.createObjectURL(file);
}
EL_browse.addEventListener('change', ev => {
EL_preview.innerHTML = ''; // Remove old images and data
const files = ev.target.files;
if (!files || !files[0]) return alert('File upload not supported');
[...files].forEach( readImage );
});
#preview img { max-height: 100px; }
<input id="browse" type="file" multiple>
<div id="preview"></div>
Example using FileReader API
In case you need images sources as long Base64 encoded data strings
<img src="data:image/png;base64,iVBORw0KGg... ...lF/++TkSuQmCC=">
const EL_browse = document.getElementById('browse');
const EL_preview = document.getElementById('preview');
const readImage = file => {
if ( !(/^image\/(png|jpe?g|gif)$/).test(file.type) )
return EL_preview.insertAdjacentHTML('beforeend', `<div>Unsupported format ${file.type}: ${file.name}</div>`);
const reader = new FileReader();
reader.addEventListener('load', () => {
const img = new Image();
img.addEventListener('load', () => {
EL_preview.appendChild(img);
EL_preview.insertAdjacentHTML('beforeend', `<div>${file.name} ${img.width}×${img.height} ${file.type} ${Math.round(file.size/1024)}KB</div>`);
});
img.src = reader.result;
});
reader.readAsDataURL(file);
};
EL_browse.addEventListener('change', ev => {
EL_preview.innerHTML = ''; // Clear Preview
const files = ev.target.files;
if (!files || !files[0]) return alert('File upload not supported');
[...files].forEach( readImage );
});
#preview img { max-height: 100px; }
<input id="browse" type="file" multiple>
<div id="preview"></div>
Demo
Not sure if it is what you want, but just simple example:
var input = document.getElementById('input');
input.addEventListener("change", function() {
var file = this.files[0];
var img = new Image();
img.onload = function() {
var sizes = {
width: this.width,
height: this.height
};
URL.revokeObjectURL(this.src);
console.log('onload: sizes', sizes);
console.log('onload: this', this);
}
var objectURL = URL.createObjectURL(file);
console.log('change: file', file);
console.log('change: objectURL', objectURL);
img.src = objectURL;
});
If you can use the jQuery validation plugin you can do it like so:
Html:
<input type="file" name="photo" id="photoInput" />
JavaScript:
$.validator.addMethod('imagedim', function(value, element, param) {
var _URL = window.URL;
var img;
if ((element = this.files[0])) {
img = new Image();
img.onload = function () {
console.log("Width:" + this.width + " Height: " + this.height);//this will give you image width and height and you can easily validate here....
return this.width >= param
};
img.src = _URL.createObjectURL(element);
}
});
The function is passed as ab onload function.
The code is taken from here
Here is a pure JavaScript example of picking an image file, displaying it, looping through the image properties, and then re-sizing the image from the canvas into an IMG tag and explicitly setting the re-sized image type to jpeg.
If you right click the top image, in the canvas tag, and choose Save File As, it will default to a PNG format. If you right click, and Save File as the lower image, it will default to a JPEG format. Any file over 400px in width is reduced to 400px in width, and a height proportional to the original file.
HTML
<form class='frmUpload'>
<input name="picOneUpload" type="file" accept="image/*" onchange="picUpload(this.files[0])" >
</form>
<canvas id="cnvsForFormat" width="400" height="266" style="border:1px solid #c3c3c3"></canvas>
<div id='allImgProperties' style="display:inline"></div>
<div id='imgTwoForJPG'></div>
SCRIPT
<script>
window.picUpload = function(frmData) {
console.log("picUpload ran: " + frmData);
var allObjtProperties = '';
for (objProprty in frmData) {
console.log(objProprty + " : " + frmData[objProprty]);
allObjtProperties = allObjtProperties + "<span>" + objProprty + ": " + frmData[objProprty] + ", </span>";
};
document.getElementById('allImgProperties').innerHTML = allObjtProperties;
var cnvs=document.getElementById("cnvsForFormat");
console.log("cnvs: " + cnvs);
var ctx=cnvs.getContext("2d");
var img = new Image;
img.src = URL.createObjectURL(frmData);
console.log('img: ' + img);
img.onload = function() {
var picWidth = this.width;
var picHeight = this.height;
var wdthHghtRatio = picHeight/picWidth;
console.log('wdthHghtRatio: ' + wdthHghtRatio);
if (Number(picWidth) > 400) {
var newHeight = Math.round(Number(400) * wdthHghtRatio);
} else {
return false;
};
document.getElementById('cnvsForFormat').height = newHeight;
console.log('width: 400 h: ' + newHeight);
//You must change the width and height settings in order to decrease the image size, but
//it needs to be proportional to the original dimensions.
console.log('This is BEFORE the DRAW IMAGE');
ctx.drawImage(img,0,0, 400, newHeight);
console.log('THIS IS AFTER THE DRAW IMAGE!');
//Even if original image is jpeg, getting data out of the canvas will default to png if not specified
var canvasToDtaUrl = cnvs.toDataURL("image/jpeg");
//The type and size of the image in this new IMG tag will be JPEG, and possibly much smaller in size
document.getElementById('imgTwoForJPG').innerHTML = "<img src='" + canvasToDtaUrl + "'>";
};
};
</script>
Here is a jsFiddle:
jsFiddle Pick, display, get properties, and Re-size an image file
In jsFiddle, right clicking the top image, which is a canvas, won't give you the same save options as right clicking the bottom image in an IMG tag.
As far as I know there is not an easy way to do this since Javascript/JQuery does not have access to the local filesystem. There are some new features in html 5 that allows you to check certain meta data such as file size but I'm not sure if you can actually get the image dimensions.
Here is an article I found regarding the html 5 features, and a work around for IE that involves using an ActiveX control. http://jquerybyexample.blogspot.com/2012/03/how-to-check-file-size-before-uploading.html
So I started experimenting with the different things that FileReader API had to offer and could create an IMG tag with a DATA URL.
Drawback: It doesn't work on mobile phones, but it works fine on Google Chrome.
$('input').change(function() {
var fr = new FileReader;
fr.onload = function() {
var img = new Image;
img.onload = function() {
//I loaded the image and have complete control over all attributes, like width and src, which is the purpose of filereader.
$.ajax({url: img.src, async: false, success: function(result){
$("#result").html("READING IMAGE, PLEASE WAIT...")
$("#result").html("<img src='" + img.src + "' />");
console.log("Finished reading Image");
}});
};
img.src = fr.result;
};
fr.readAsDataURL(this.files[0]);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="file" accept="image/*" capture="camera">
<div id='result'>Please choose a file to view it. <br/>(Tested successfully on Chrome - 100% SUCCESS RATE)</div>
(see this on a jsfiddle at http://jsfiddle.net/eD2Ez/530/)
(see the original jsfiddle that i added upon to at http://jsfiddle.net/eD2Ez/)
A working jQuery validate example:
$(function () {
$('input[type=file]').on('change', function() {
var $el = $(this);
var files = this.files;
var image = new Image();
image.onload = function() {
$el
.attr('data-upload-width', this.naturalWidth)
.attr('data-upload-height', this.naturalHeight);
}
image.src = URL.createObjectURL(files[0]);
});
jQuery.validator.unobtrusive.adapters.add('imageminwidth', ['imageminwidth'], function (options) {
var params = {
imageminwidth: options.params.imageminwidth.split(',')
};
options.rules['imageminwidth'] = params;
if (options.message) {
options.messages['imageminwidth'] = options.message;
}
});
jQuery.validator.addMethod("imageminwidth", function (value, element, param) {
var $el = $(element);
if(!element.files && element.files[0]) return true;
return parseInt($el.attr('data-upload-width')) >= parseInt(param["imageminwidth"][0]);
});
} (jQuery));