I have a button where you can upload an image and insert it in a tag, it works on every browser but not on chrome. The first reader.onloadend is processed, I can log image and image.src.
var inputUpload = document.getElementById('buttonUpload');
inputUpload.addEventListener('change', (e) => {
const file = e.target.files[0];
const reader = new FileReader();
reader.onloadend = () => {
//Initiate the JavaScript Image object.
var image = new Image();
image.src = reader.result;
console.log('image.src');
image.onloadend = function() { /* execution stops here */
var height = this.height;
var width = this.width;
if (height > 150 || width > 150) {
showAlert('Image dimensions must be within 150×150 pixels.');
} else {
// convert file to base64 String
const base64String = reader.result.replace('data:', '').replace(/^.+,/, '');
// display image
valueImg = "data:image/png;base64," + base64String;
updateImg(valueImg);
};
};
};
reader.readAsDataURL(file);
});
<button id="buttonUpload" type="button" class="d-inline btn-custom mx-0">
Upload
</button>
When I select the image file, it stops at image.loadend but I get no errors in the console
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 + ')';
}
}
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>
I have a JPS with a form in which a user can put an image:
<div class="photo">
<div>Photo (max 240x240 and 100 kb):</div>
<input type="file" name="photo" id="photoInput" onchange="checkPhoto(this)"/>
</div>
I have written this js:
function checkPhoto(target) {
if(target.files[0].type.indexOf("image") == -1) {
document.getElementById("photoLabel").innerHTML = "File not supported";
return false;
}
if(target.files[0].size > 102400) {
document.getElementById("photoLabel").innerHTML = "Image too big (max 100kb)";
return false;
}
document.getElementById("photoLabel").innerHTML = "";
return true;
}
which works fine to check file type and size. Now I want to check image width and height but I cannot do it.
I have tried with target.files[0].width but I get undefined. With other ways I get 0.
Any suggestions?
The file is just a file, you need to create an image like so:
var _URL = window.URL || window.webkitURL;
$("#file").change(function (e) {
var file, img;
if ((file = this.files[0])) {
img = new Image();
var objectUrl = _URL.createObjectURL(file);
img.onload = function () {
alert(this.width + " " + this.height);
_URL.revokeObjectURL(objectUrl);
};
img.src = objectUrl;
}
});
Demo: http://jsfiddle.net/4N6D9/1/
I take it you realize this is only supported in a few browsers. Mostly firefox and chrome, could be opera as well by now.
P.S. The URL.createObjectURL() method has been removed from the MediaStream interface. This method has been deprecated in 2013 and superseded by assigning streams to HTMLMediaElement.srcObject. The old method was removed because it is less safe, requiring a call to URL.revokeOjbectURL() to end the stream. Other user agents have either deprecated (Firefox) or removed (Safari) this feature feature.
For more information, please refer here.
In my view the perfect answer you must required is
var reader = new FileReader();
//Read the contents of Image File.
reader.readAsDataURL(fileUpload.files[0]);
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;
if (height > 100 || width > 100) {
alert("Height and Width must not exceed 100px.");
return false;
}
alert("Uploaded image has valid Height and Width.");
return true;
};
};
I agree. Once it is uploaded to somewhere the user's browser can access then it is pretty easy to get the size. As you need to wait for the image to load you'll want to hook into the onload event for img.
Updated example:
// async/promise function for retrieving image dimensions for a URL
function imageSize(url) {
const img = document.createElement("img");
const promise = new Promise((resolve, reject) => {
img.onload = () => {
// Natural size is the actual image size regardless of rendering.
// The 'normal' `width`/`height` are for the **rendered** size.
const width = img.naturalWidth;
const height = img.naturalHeight;
// Resolve promise with the width and height
resolve({width, height});
};
// Reject promise on error
img.onerror = reject;
});
// Setting the source makes it start downloading and eventually call `onload`
img.src = url;
return promise;
}
// How to use in an async function
(async() => {
const imageUrl = 'http://your.website.com/userUploadedImage.jpg';
const imageDimensions = await imageSize(imageUrl);
console.info(imageDimensions); // {width: 1337, height: 42}
})();
Older example:
var width, height;
var img = document.createElement("img");
img.onload = function() {
// `naturalWidth`/`naturalHeight` aren't supported on <IE9. Fallback to normal width/height
// The natural size is the actual image size regardless of rendering.
// The 'normal' width/height are for the **rendered** size.
width = img.naturalWidth || img.width;
height = img.naturalHeight || img.height;
// Do something with the width and height
}
// Setting the source makes it start downloading and eventually call `onload`
img.src = "http://your.website.com/userUploadedImage.jpg";
This is the easiest way to check the size
let img = new Image()
img.src = window.URL.createObjectURL(event.target.files[0])
img.onload = () => {
alert(img.width + " " + img.height);
}
Check for specific size. Using 100 x 100 as example
let img = new Image()
img.src = window.URL.createObjectURL(event.target.files[0])
img.onload = () => {
if(img.width === 100 && img.height === 100){
alert(`Nice, image is the right size. It can be uploaded`)
// upload logic here
} else {
alert(`Sorry, this image doesn't look like the size we wanted. It's
${img.width} x ${img.height} but we require 100 x 100 size image.`);
}
}
Attach the function to the onchange method of the input type file /onchange="validateimg(this)"/
function validateimg(ctrl) {
var fileUpload = ctrl;
var regex = new RegExp("([a-zA-Z0-9\s_\\.\-:])+(.jpg|.png|.gif)$");
if (regex.test(fileUpload.value.toLowerCase())) {
if (typeof (fileUpload.files) != "undefined") {
var reader = new FileReader();
reader.readAsDataURL(fileUpload.files[0]);
reader.onload = function (e) {
var image = new Image();
image.src = e.target.result;
image.onload = function () {
var height = this.height;
var width = this.width;
if (height < 1100 || width < 750) {
alert("At least you can upload a 1100*750 photo size.");
return false;
}else{
alert("Uploaded image has valid Height and Width.");
return true;
}
};
}
} else {
alert("This browser does not support HTML5.");
return false;
}
} else {
alert("Please select a valid Image file.");
return false;
}
}
const ValidateImg = (file) =>{
let img = new Image()
img.src = window.URL.createObjectURL(file)
img.onload = () => {
if(img.width === 100 && img.height ===100){
alert("Correct size");
return true;
}
alert("Incorrect size");
return true;
}
}
I think this may be the simplest for uploads if you want to use it other functions.
async function getImageDimensions(file) {
let img = new Image();
img.src = URL.createObjectURL(file);
await img.decode();
let width = img.width;
let height = img.height;
return {
width,
height,
}
}
Use like
const {width, height } = await getImageDimensions(file)
Suppose you were storing an image for Tiger taken in Kenya. So you could use it like to upload to cloud storage and then store photo information.
const addImage = async (file, title, location) => {
const { width, height } = await getImageDimensions(file)
const url = await uploadToCloudStorage(file) // returns storage url
await addToDatabase(url, width, height, title, location)
}
function validateimg(ctrl) {
var fileUpload = $("#txtPostImg")[0];
var regex = new RegExp("([a-zA-Z0-9\s_\\.\-:])+(.jpg|.png|.gif)$");
if (regex.test(fileUpload.value.toLowerCase())) {
if (typeof (fileUpload.files) != "undefined") {
var reader = new FileReader();
reader.readAsDataURL(fileUpload.files[0]);
reader.onload = function (e) {
var image = new Image();
image.src = e.target.result;
image.onload = function () {
var height = this.height;
var width = this.width;
console.log(this);
if ((height >= 1024 || height <= 1100) && (width >= 750 || width <= 800)) {
alert("Height and Width must not exceed 1100*800.");
return false;
}
alert("Uploaded image has valid Height and Width.");
return true;
};
}
} else {
alert("This browser does not support HTML5.");
return false;
}
} else {
alert("Please select a valid Image file.");
return false;
}
}
You can do the steps for previewing the image without showing it which is supported on all browsers. Following js code shows you how to check the width and height :
var file = e.target.files[0];
if (/\.(jpe?g|png|gif)$/i.test(file.name)) {
var reader = new FileReader();
reader.addEventListener("load", function () {
var image = new Image();
image.src = this.result as string;
image.addEventListener('load', function () {
console.log(`height: ${this.height}, width: ${this.width}`);
});
}, false);
reader.readAsDataURL(file);
}
Based on Mozilla docs:
The readAsDataURL method is used to read the contents of the specified
Blob or File. When the read operation is finished, the readyState
becomes DONE, and the loadend is triggered. At that time, the result
attribute contains the data as a data: URL representing the file's
data as a base64 encoded string.
And the browser compatibility is listed too.
In my case, I needed to also prevent the form from being submited, so here is the solution that worked for me.
The preventDefault will stop the form action, then we check the size and dimensions of the image in the onload function.
If all good, we allow the submit.
As the submit button gets disabled if a user still tries to submit the form with an invalid image, I also had to re-able the submit button once a valid image is inputted.
const validateMaxImageFileSize = (e) => {
e.preventDefault();
const el = $("input[type='file']")[0];
if (el.files && el.files[0]) {
const file = el.files[0];
const maxFileSize = 5242880; // 5 MB
const maxWidth = 1920;
const maxHeight = 1080;
const img = new Image();
img.src = window.URL.createObjectURL(file);
img.onload = () => {
if (file.type.match('image.*') && file.size > maxFileSize) {
alert('The selected image file is too big. Please choose one that is smaller than 5 MB.');
} else if (file.type.match('image.*') && (img.width > maxWidth || img.height > maxHeight)) {
alert(`The selected image is too big. Please choose one with maximum dimensions of ${maxWidth}x${maxHeight}.`);
} else {
e.target.nodeName === 'INPUT'
? (e.target.form.querySelector("input[type='submit']").disabled = false)
: e.target.submit();
}
};
}
};
$('form.validate-image-size').on('submit', validateMaxImageFileSize);
$("form.validate-image-size input[type='file']").on('change', validateMaxImageFileSize);
function uploadfile(ctrl) {
var validate = validateimg(ctrl);
if (validate) {
if (window.FormData !== undefined) {
ShowLoading();
var fileUpload = $(ctrl).get(0);
var files = fileUpload.files;
var fileData = new FormData();
for (var i = 0; i < files.length; i++) {
fileData.append(files[i].name, files[i]);
}
fileData.append('username', 'Wishes');
$.ajax({
url: 'UploadWishesFiles',
type: "POST",
contentType: false,
processData: false,
data: fileData,
success: function(result) {
var id = $(ctrl).attr('id');
$('#' + id.replace('txt', 'hdn')).val(result);
$('#imgPictureEn').attr('src', '../Data/Wishes/' + result).show();
HideLoading();
},
error: function(err) {
alert(err.statusText);
HideLoading();
}
});
} else {
alert("FormData is not supported.");
}
}