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I'm new to python i did one application using python in that i want to capture Images from my webcam using html and AJAX javascript and save it to server side python. I have completed capturing of images from using client side HTML but i don't know how to save and pass the data from html client side to server side python.If anybody did this please can you help me... THANK YOU IN ADVANCE... My.html:
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Get User Media - Photo</title>
</head>
<body>
<button id="take">Take a photo</button><br />
<video id="v"></video>
<canvas id="canvas" style="display:none;"></canvas>
<img src="D:/VoteTest/img.jpg" id="photo" alt="photo">
<script>
;(function(){
function userMedia(){
return navigator.getUserMedia = navigator.getUserMedia ||
navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia ||
navigator.msGetUserMedia || null;
}
// Now we can use it
if( userMedia() ){
var videoPlaying = false;
var constraints = {
video: true,
audio:false
};
var video = document.getElementById('v');
var media = navigator.getUserMedia(constraints, function(stream){
// URL Object is different in WebKit
var url = window.URL || window.webkitURL;
// create the url and set the source of the video element
video.src = url ? url.createObjectURL(stream) : stream;
// Start the video
video.play();
videoPlaying = true;
}, function(error){
console.log("ERROR");
console.log(error);
});
// Listen for user click on the "take a photo" button
document.getElementById('take').addEventListener('click', function(){
if (videoPlaying){
var canvas = document.getElementById('canvas');
canvas.width = video.videoWidth;
canvas.height = video.videoHeight;
canvas.getContext('2d').drawImage(video, 0, 0);
var data = canvas.toDataURL('image/webp');
document.getElementById('photo').setAttribute('src', data);
}
}, false);
} else {
console.log("KO");
}
})();
</script>
</body>
</html>
454
I just did this recently for a project. You can use XHR to send the image inside form data:
let formdata = new FormData();
formdata.append("image", data);
let xhr = new XMLHttpRequest();
xhr.open('POST', 'http://yourserver/image', true);
xhr.onload = function () {
if (this.status === 200)
console.log(this.response);
else
console.error(xhr);
};
xhr.send(formdata);
I had trouble using the toDataURL to convert the canvas, so I used toBlob for an easier conversion:
canvas.toBlob(callBackToMyPostFunctionAbove, 'image/jpeg');
Here is a sample HTML file with embedded JavaScript and my Python server.
HTML & Embedded JavaScript
The JavaScript uses:
The code:
<!DOCTYPE html>
<html>
<head>
<title>Post an Image test</title>
<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script>
</head>
<style>
/* mirror the image */
video, canvas {
transform: scale(-1, 1); /*For Firefox (& IE) */
-webkit-transform: scale(-1, 1); /*for Chrome & Opera (& Safari) */
}
</style>
<body>
<video id="myVideo" autoplay></video>
<script>
let v = document.getElementById("myVideo");
//create a canvas to grab an image for upload
let imageCanvas = document.createElement('canvas');
let imageCtx = imageCanvas.getContext("2d");
//Add file blob to a form and post
function postFile(file) {
let formdata = new FormData();
formdata.append("image", file);
let xhr = new XMLHttpRequest();
xhr.open('POST', 'http://localhost:5000/image', true);
xhr.onload = function () {
if (this.status === 200)
console.log(this.response);
else
console.error(xhr);
};
xhr.send(formdata);
}
//Get the image from the canvas
function sendImagefromCanvas() {
//Make sure the canvas is set to the current video size
imageCanvas.width = v.videoWidth;
imageCanvas.height = v.videoHeight;
imageCtx.drawImage(v, 0, 0, v.videoWidth, v.videoHeight);
//Convert the canvas to blob and post the file
imageCanvas.toBlob(postFile, 'image/jpeg');
}
//Take a picture on click
v.onclick = function() {
console.log('click');
sendImagefromCanvas();
};
window.onload = function () {
//Get camera video
navigator.mediaDevices.getUserMedia({video: {width: 1280, height: 720}, audio: false})
.then(stream => {
v.srcObject = stream;
})
.catch(err => {
console.log('navigator.getUserMedia error: ', err)
});
};
</script>
</body>
</html>
This uses adapter.js to polyfill getUserMedia on different browsers without any error checks.
Python Server
And here is a sample in Python using Flask as a web server:
from flask import Flask, request, Response
import time
PATH_TO_TEST_IMAGES_DIR = './images'
app = Flask(__name__)
@app.route('/')
def index():
return Response(open('./static/getImage.html').read(), mimetype="text/html")
# save the image as a picture
@app.route('/image', methods=['POST'])
def image():
i = request.files['image'] # get the image
f = ('%s.jpeg' % time.strftime("%Y%m%d-%H%M%S"))
i.save('%s/%s' % (PATH_TO_TEST_IMAGES_DIR, f))
return Response("%s saved" % f)
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0')
If you are looking for php in server side, here is how I did it.
Post the image data to php script using jquery:
var imgData = canvas.toDataURL('image/png');
$.post("https://path-to-your-script/capture.php", {image: imgData},
function(data) {
console.log('posted');
});
The php script will be like:
capture.php
$data = $_POST['image'];
// remove "data:image/png;base64," from image data.
$data = str_replace("data:image/png;base64,", "", $data);
// save to file
file_put_contents("/tmp/image.png", base64_decode($data));
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