I am using the following sample to resize the uploaded images with Blazor WebAssembly
https://www.prowaretech.com/Computer/Blazor/Examples/WebApi/UploadImages .
Still I need the original file too to be converted to base64 too and I don't know how can I access it...
I tried to find the file's original width and height to pass its to RequestImageFileAsync function but no success...
I need to store both files : the original one and the resized one.
Can you help me, please ?
Thank You Very Much !
The InputFile control emits an IBrowserFile type. RequestImageFileAsync is a convenience method on IBrowserFile to resize the image and convert the type. The result is still an IBrowserFile.
One way to do what you are asking is with SixLabors.ImageSharp. Based on the ProWareTech example, something like this...
async Task OnChange(InputFileChangeEventArgs e)
{
var files = e.GetMultipleFiles(); // get the files selected by the users
foreach(var file in files)
{
//Original-sized file
var buf1 = new byte[file.Size];
using (var stream = file.OpenReadStream())
{
await stream.ReadAsync(buf1); // copy the stream to the buffer
}
origFilesBase64.Add(new ImageFile { base64data = Convert.ToBase64String(buf1), contentType = file.ContentType, fileName = file.Name }); // convert to a base64 string!!
//Resized File
var resizedFile = await file.RequestImageFileAsync(file.ContentType, 640, 480); // resize the image file
var buf = new byte[resizedFile.Size]; // allocate a buffer to fill with the file's data
using (var stream = resizedFile.OpenReadStream())
{
await stream.ReadAsync(buf); // copy the stream to the buffer
}
filesBase64.Add(new ImageFile { base64data = Convert.ToBase64String(buf), contentType = file.ContentType, fileName = file.Name }); // convert to a base64 string!!
}
//To get the image Sizes for first image
ImageSharp.Image origImage = Image.Load<*imagetype*>(origFilesBase64[0])
int origImgHeight = origImage.Height;
int origImgWidth = origImage.Width;
ImageSharp.Image resizedImage = Image.Load<*imagetype*>(filesBase64[0])
int resizedImgHeight = resizedImage.Height;
int resizedImgWidth = resizedImage.Width;
}
I am trying to compress an image client-side (Angular 2/Ionic 3) and When I log the file that is created by the camera, it says:
"type":null when it should say "type":'image/jpeg'.
I am using the Ionic camera plugin to handle taking a picture or choosing one from the photo library, after that (I assume) the file is created without a type. Every compression tool I have tried has had this problem, and I have run out of options. Is there a way to change the type of a File object?
I created a new Blob with this method and made sure to give it image type:
dataURItoBlob(dataURI, callback): Promise<any> {
return new Promise((resolve, reject) => {
let byteString = atob(dataURI);
//console.log(byteString);
// separate out the mime component
//let mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0]
// write the bytes of the string to an ArrayBuffer
let ab = new ArrayBuffer(byteString.length);
let ia = new Uint8Array(ab);
for (let i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
// write the ArrayBuffer to a blob, and you're done
let bb = new Blob([ab], {type: 'image/jpeg'});
resolve(bb);
})
}
I used it after reading the contents of the image to base64 like this and got the resulting blob with image type:
var readerZ = new FileReader();
readerZ.onload = (e) => {
let data = readerZ.result.split(',')[1];
//console.log(data);
self.dataURItoBlob(data, null).then(blob => {
I am using the S3 adaptor to save images to my S3 bucket. My client code is:
var saveFileToParse = function(imageData) {
var parseFile = new Parse.File(Parse.User.current().id + " Image", {
base64: imageData
});
$ionicLoading.show();
parseFile.save().then(function(response) {
if (angular.isNumber($scope.activeExercise.images[0])) {
$scope.activeExercise.images = [];
}
var imageUrl = response._url;
$scope.activeExercise.images.push(imageUrl);
$scope.$apply();
$scope.customImage = true;
$ionicLoading.hide();
}).then(function(imageUrl) {
var file = new Parse.Object("Files");
file.set("file", parseFile);
file.save().then(function(response) {
$ionicLoading.hide();
});
},
function(error) {
$ionicLoading.hide();
errorFactory.checkError(error);
});
};
The file is being saved, however is being saved as a .txt file, I expect because of the base 64, however this was never an issue on parse.com. Can I explicitly make this save as .jpg?
EDIT:
I am employed the code below and this gives a different filename and shows as an image in S3. However, when downloaded it still has a .txt file extension. I have even changed my save command to include the mime-type var parseFile = new Parse.File(name, file, "image/jpeg");
The issue here was caused by the old parse.com server automatically applying %20 when there was a space in the file URL.
Removing the space made it work.
Honestly, you just need to read the documentation thoroughly. The answer is already available there, so just pass the file object.
var fileUploadControl = $("#profilePhotoFileUpload")[0];
if (fileUploadControl.files.length > 0) {
var file = fileUploadControl.files[0];
var name = "photo.jpg";
var parseFile = new Parse.File(name, file);
parseFile.save().then(function () {
// The file has been saved to Parse.
}, function (error) {
// The file either could not be read, or could not be saved to Parse.
});
}
I'm trying to allow users to upload images and then store the images, base64 encoded, in firebase. I'm trying to make my firebase structured as follows:
|--Feed
|----Feed Item
|------username
|------epic
|---------name,etc.
|------images
|---------image1, image 2, etc.
However, I can't get the remote data in firebase to mirror the local data in the client. When I print the array of images to the console in the client, it shows that the uploaded images have been added to the array of images...but these images never make it to firebase. I've tried doing this multiple ways to no avail. I tried using implicit syncing, explicit syncing, and a mixture of both. I can;t for the life of me figure out why this isn;t working and I'm getting pretty frustrated. Here's my code:
$scope.complete = function(epicName){
for (var i = 0; i < $scope.activeEpics.length; i++){
if($scope.activeEpics[i].id === epicName){
var epicToAdd = $scope.activeEpics[i];
}
}
var epicToAddToFeed = {epic: epicToAdd, username: $scope.currUser.username, userImage: $scope.currUser.image, props:0, images:['empty']};
//connect to feed data
var feedUrl = "https://myfirebaseurl.com/feed";
$scope.feed = angularFireCollection(new Firebase(feedUrl));
//add epic
var added = $scope.feed.add(epicToAddToFeed).name();
//connect to added epic in firebase
var addedUrl = "https://myfirebaseurl.com/feed/" + added;
var addedRef = new Firebase(addedUrl);
angularFire(addedRef, $scope, 'added').then(function(){
// for each image uploaded, add image to the added epic's array of images
for (var i = 0, f; f = $scope.files[i]; i++) {
var reader = new FileReader();
reader.onload = (function(theFile) {
return function(e) {
var filePayload = e.target.result;
$scope.added.images.push(filePayload);
};
})(f);
reader.readAsDataURL(f);
}
});
}
EDIT: Figured it out, had to connect to "https://myfirebaseurl.com/feed/" + added + "/images"
My Express app is receiving a base64-encoded PNG from the browser (generated from canvas with toDataURL() ) and writing it to a file. But the file isn't a valid image file, and the "file" utility simply identifies it as "data".
var body = req.rawBody,
base64Data = body.replace(/^data:image\/png;base64,/,""),
binaryData = new Buffer(base64Data, 'base64').toString('binary');
require("fs").writeFile("out.png", binaryData, "binary", function(err) {
console.log(err); // writes out file without error, but it's not a valid image
});
I think you are converting the data a bit more than you need to. Once you create the buffer with the proper encoding, you just need to write the buffer to the file.
var base64Data = req.rawBody.replace(/^data:image\/png;base64,/, "");
require("fs").writeFile("out.png", base64Data, 'base64', function(err) {
console.log(err);
});
new Buffer(..., 'base64') will convert the input string to a Buffer, which is just an array of bytes, by interpreting the input as a base64 encoded string. Then you can just write that byte array to the file.
Update
As mentioned in the comments, req.rawBody is no longer a thing. If you are using express/connect then you should use the bodyParser() middleware and use req.body, and if you are doing this using standard Node then you need to aggregate the incoming data event Buffer objects and do this image data parsing in the end callback.
this is my full solution which would read any base64 image format and save it in the proper format in the database:
// Save base64 image to disk
try
{
// Decoding base-64 image
// Source: http://stackoverflow.com/questions/20267939/nodejs-write-base64-image-file
function decodeBase64Image(dataString)
{
var matches = dataString.match(/^data:([A-Za-z-+\/]+);base64,(.+)$/);
var response = {};
if (matches.length !== 3)
{
return new Error('Invalid input string');
}
response.type = matches[1];
response.data = new Buffer(matches[2], 'base64');
return response;
}
// Regular expression for image type:
// This regular image extracts the "jpeg" from "image/jpeg"
var imageTypeRegularExpression = /\/(.*?)$/;
// Generate random string
var crypto = require('crypto');
var seed = crypto.randomBytes(20);
var uniqueSHA1String = crypto
.createHash('sha1')
.update(seed)
.digest('hex');
var base64Data = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEAZABkAAD/4Q3zaHR0cDovL25zLmFkb2JlLmN...';
var imageBuffer = decodeBase64Image(base64Data);
var userUploadedFeedMessagesLocation = '../img/upload/feed/';
var uniqueRandomImageName = 'image-' + uniqueSHA1String;
// This variable is actually an array which has 5 values,
// The [1] value is the real image extension
var imageTypeDetected = imageBuffer
.type
.match(imageTypeRegularExpression);
var userUploadedImagePath = userUploadedFeedMessagesLocation +
uniqueRandomImageName +
'.' +
imageTypeDetected[1];
// Save decoded binary image to disk
try
{
require('fs').writeFile(userUploadedImagePath, imageBuffer.data,
function()
{
console.log('DEBUG - feed:message: Saved to disk image attached by user:', userUploadedImagePath);
});
}
catch(error)
{
console.log('ERROR:', error);
}
}
catch(error)
{
console.log('ERROR:', error);
}
This did it for me simply and perfectly.
Excellent explanation by Scott Robinson
From image to base64 string
let buff = fs.readFileSync('stack-abuse-logo.png');
let base64data = buff.toString('base64');
From base64 string to image
let buff = Buffer.from(data, 'base64');
fs.writeFileSync('stack-abuse-logo-out.png', buff);
UPDATE
I found this interesting link how to solve your problem in PHP. I think you forgot to replace space by +as shown in the link.
I took this circle from http://images-mediawiki-sites.thefullwiki.org/04/1/7/5/6204600836255205.png as sample which looks like:
Next I put it through http://www.greywyvern.com/code/php/binary2base64 which returned me:
data:image/png;base64,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
saved this string to base64 which I read from in my code.
var fs = require('fs'),
data = fs.readFileSync('base64', 'utf8'),
base64Data,
binaryData;
base64Data = data.replace(/^data:image\/png;base64,/, "");
base64Data += base64Data.replace('+', ' ');
binaryData = new Buffer(base64Data, 'base64').toString('binary');
fs.writeFile("out.png", binaryData, "binary", function (err) {
console.log(err); // writes out file without error, but it's not a valid image
});
I get a circle back, but the funny thing is that the filesize has changed :)...
END
When you read back image I think you need to setup headers
Take for example imagepng from PHP page:
<?php
$im = imagecreatefrompng("test.png");
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
?>
I think the second line header('Content-Type: image/png');, is important else your image will not be displayed in browser, but just a bunch of binary data is shown to browser.
In Express you would simply just use something like below. I am going to display your gravatar which is located at http://www.gravatar.com/avatar/cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG
and is a jpeg file when you curl --head http://www.gravatar.com/avatar/cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG. I only request headers because else curl will display a bunch of binary stuff(Google Chrome immediately goes to download) to console:
curl --head "http://www.gravatar.com/avatar/cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG"
HTTP/1.1 200 OK
Server: nginx
Date: Wed, 03 Aug 2011 12:11:25 GMT
Content-Type: image/jpeg
Connection: keep-alive
Last-Modified: Mon, 04 Oct 2010 11:54:22 GMT
Content-Disposition: inline; filename="cabf735ce7b8b4471ef46ea54f71832d.jpeg"
Access-Control-Allow-Origin: *
Content-Length: 1258
X-Varnish: 2356636561 2352219240
Via: 1.1 varnish
Expires: Wed, 03 Aug 2011 12:16:25 GMT
Cache-Control: max-age=300
Source-Age: 1482
$ mkdir -p ~/tmp/6922728
$ cd ~/tmp/6922728/
$ touch app.js
app.js
var app = require('express').createServer();
app.get('/', function (req, res) {
res.contentType('image/jpeg');
res.sendfile('cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG');
});
app.get('/binary', function (req, res) {
res.sendfile('cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG');
});
app.listen(3000);
$ wget "http://www.gravatar.com/avatar/cabf735ce7b8b4471ef46ea54f71832d?s=32&d=identicon&r=PG"
$ node app.js
I also had to save Base64 encoded images that are part of data URLs, so I ended up making a small npm module to do it in case I (or someone else) needed to do it again in the future. It's called ba64.
Simply put, it takes a data URL with a Base64 encoded image and saves the image to your file system. It can save synchronously or asynchronously. It also has two helper functions, one to get the file extension of the image, and the other to separate the Base64 encoding from the data: scheme prefix.
Here's an example:
var ba64 = require("ba64"),
data_url = "data:image/jpeg;base64,[Base64 encoded image goes here]";
// Save the image synchronously.
ba64.writeImageSync("myimage", data_url); // Saves myimage.jpeg.
// Or save the image asynchronously.
ba64.writeImage("myimage", data_url, function(err){
if (err) throw err;
console.log("Image saved successfully");
// do stuff
});
Install it: npm i ba64 -S. Repo is on GitHub: https://github.com/HarryStevens/ba64.
P.S. It occurred to me later that ba64 is probably a bad name for the module since people may assume it does Base64 encoding and decoding, which it doesn't (there are lots of modules that already do that). Oh well.
Below function to save files, just pass your base64 file, it return filename save it in DB.
import fs from 'fs';
const uuid = require('uuid/v1');
/*Download the base64 image in the server and returns the filename and path of image.*/
function saveImage(baseImage) {
/*path of the folder where your project is saved. (In my case i got it from config file, root path of project).*/
const uploadPath = "/home/documents/project";
//path of folder where you want to save the image.
const localPath = `${uploadPath}/uploads/images/`;
//Find extension of file
const ext = baseImage.substring(baseImage.indexOf("/")+1, baseImage.indexOf(";base64"));
const fileType = baseImage.substring("data:".length,baseImage.indexOf("/"));
//Forming regex to extract base64 data of file.
const regex = new RegExp(`^data:${fileType}\/${ext};base64,`, 'gi');
//Extract base64 data.
const base64Data = baseImage.replace(regex, "");
const filename = `${uuid()}.${ext}`;
//Check that if directory is present or not.
if(!fs.existsSync(`${uploadPath}/uploads/`)) {
fs.mkdirSync(`${uploadPath}/uploads/`);
}
if (!fs.existsSync(localPath)) {
fs.mkdirSync(localPath);
}
fs.writeFileSync(localPath+filename, base64Data, 'base64');
return filename;
}
You can use a third-party library like base64-img or base64-to-image.
base64-img
const base64Img = require('base64-img');
const data = 'data:image/png;base64,...';
const destpath = 'dir/to/save/image';
const filename = 'some-filename';
base64Img.img(data, destpath, filename, (err, filepath) => {}); // Asynchronous using
const filepath = base64Img.imgSync(data, destpath, filename); // Synchronous using
base64-to-image
const base64ToImage = require('base64-to-image');
const base64Str = 'data:image/png;base64,...';
const path = 'dir/to/save/image/'; // Add trailing slash
const optionalObj = { fileName: 'some-filename', type: 'png' };
const { imageType, fileName } = base64ToImage(base64Str, path, optionalObj); // Only synchronous using
Converting from file with base64 string to png image.
4 variants which works.
var {promisify} = require('util');
var fs = require("fs");
var readFile = promisify(fs.readFile)
var writeFile = promisify(fs.writeFile)
async function run () {
// variant 1
var d = await readFile('./1.txt', 'utf8')
await writeFile("./1.png", d, 'base64')
// variant 2
var d = await readFile('./2.txt', 'utf8')
var dd = new Buffer(d, 'base64')
await writeFile("./2.png", dd)
// variant 3
var d = await readFile('./3.txt')
await writeFile("./3.png", d.toString('utf8'), 'base64')
// variant 4
var d = await readFile('./4.txt')
var dd = new Buffer(d.toString('utf8'), 'base64')
await writeFile("./4.png", dd)
}
run();
Easy way to convert base64 image into file and save as some random id or name.
// to create some random id or name for your image name
const imgname = new Date().getTime().toString();
// to declare some path to store your converted image
const path = yourpath.png
// image takes from body which you uploaded
const imgdata = req.body.image;
// to convert base64 format into random filename
const base64Data = imgdata.replace(/^data:([A-Za-z-+/]+);base64,/, '');
fs.writeFile(path, base64Data, 'base64', (err) => {
console.log(err);
});
// assigning converted image into your database
req.body.coverImage = imgname
is very simple
const path = require('path');
const { readFile, stat, writeFile } = require("fs/promises");
(async () => {
try {
const contents = await readFile(path.join(__dirname, 'clau.jpg'), { encoding: 'base64' });
console.log(contents);
await writeFile(path.join(__dirname, 'claumia.jpg'), Buffer.from(contents, 'base64'));
} catch (error) {
console.log(error)
}
})()