Download canvas as image

EL metodo HTMLCanvasElement.toBlob() crea un objeto Blob que representa la imagen contenida en el canvas; este archivo puede ser cacheado en el disco oo guardado en la memoria a desicion del user agent. Si la propiedad type no se especifica el tipo de la imagen será image/png. La imagen creada tiene una resolución de 96dpi. El tercer argumento es usado con las imagenes image/jpeg para especificar la calidad de salida.Syntaxvoid canvas.toBlob(callback, type, encoderOptions);Parameters callback A callback function with the resulting Blob object as a single argument. type Optional A DOMString indicating the image format. The default type is image/png. encoderOptions Optional A Number between 0 and 1 indicating image quality if the requested type is image/jpeg or image/webp. If this argument is anything else, the default value for image quality is used. Other arguments are ignored.Return valueNone.ExamplesGetting a file representing the canvasOnce you have drawn content into a canvas, you can convert it into a file of any supported image format. The code snippet below, for example, takes the image in the element whose ID is "canvas", obtains a copy of it as a PNG image, then appends a new element to the document, whose source image is the one created using the canvas.var canvas = document.getElementById("canvas");canvas.toBlob(function(blob) { var newImg = document.createElement("img"), url = URL.createObjectURL(blob); newImg.onload = function() { // no longer need to read the blob so it's revoked URL.revokeObjectURL(url); }; newImg.src = url; document.body.appendChild(newImg);});Note that here we're creating a PNG image; if you add a second parameter to the toBlob() call, you can specify the image type. For example, to get the image in JPEG format: canvas.toBlob(function(blob){...}, "image/jpeg", 0.95); // JPEG at 95% qualityA way to convert a canvas to an ico (Mozilla only)This uses -moz-parse to convert the canvas to ico. Windows XP doesn't support converting from PNG to ico, so it uses bmp instead. A download link is created by setting the download attribute. The value of the download attribute is the name it will use as the file name.var canvas = document.getElementById("canvas");var d = canvas.width;ctx = canvas.getContext("2d");ctx.beginPath();ctx.moveTo(d / 2, 0);ctx.lineTo(d, d);ctx.lineTo(0, d);ctx.closePath();ctx.fillStyle = "yellow";ctx.fill();function blobCallback(iconName)

Download source - 32.78 KBIntroductionThis project shows how to create a download animation in WPF using a simple UserControl and code-behind animation. BackgroundI needed a download animation in my WPF application and I started looking for a way to use animated GIFs in WPF. I found out that animated GIFs aren't directly supported in WPF, so I decided to make my own WPF user control. UsageMany applications download stuff from the Internet, for example when you check for updates to your application. Showing a download animation while your application is contacting the web server and downloading data makes the waiting time more acceptable to the user. This project provides a simple WPF UserControl that contains a download animation. What You Will LearnIf you are a beginner in WPF, this project gives you a quick introduction to user controls, control styling and control positioning using a Canvas layout. The animation is controlled by a timer in the code-behind. Design of the ControlI started out by adding a UserControl to my Visual Studio project. Then I added a Canvas control and two Image controls. One image on the left side shows a globe and one on the right side shows a PC. In between the images, I made a dotted line using Ellipse controls. The animated part consists of three orange dots sliding from left to right. The Start and Stop buttons are used for testing and are not part of the UserControl. XAMLThe XAML code for the UserControl is shown below: UserControl x:Class="WpfDownloadAnimation.DownloadAnimationControl" xmlns=" xmlns:x=" UserControl.Resources> Style TargetType="Ellipse"> Setter Property="Fill" Value="LightGray" /> Setter Property="Width" Value="8" /> Setter Property="Height" Value="8" /> /Style> /UserControl.Resources> Canvas Height="58" Width="275"> Ellipse Canvas.Left="56" Canvas.Top="23" /> Ellipse Canvas.Left="70" Canvas.Top="23" /> Ellipse Canvas.Left="84" Canvas.Top="23" /> Ellipse Canvas.Left="98" Canvas.Top="23" /> Ellipse Canvas.Left="112" Canvas.Top="23" /> Ellipse Canvas.Left="126" Canvas.Top="23" /> Ellipse Canvas.Left="140" Canvas.Top="23" /> Ellipse Canvas.Left="154" Canvas.Top="23" /> Ellipse Canvas.Left="168" Canvas.Top="23" /> Ellipse Canvas.Left="182" Canvas.Top="23" /> Ellipse Canvas.Left="196" Canvas.Top="23" /> Ellipse Canvas.Left="210" Canvas.Top="23" /> Canvas Canvas.Left="10" Canvas.Top="19" Name="SlidingCanvas" Height="17" Width="46"> Ellipse Canvas.Left="4" Canvas.Top="4" Fill="Orange" /> Ellipse Canvas.Left="18" Canvas.Top="4" Fill="Orange" /> Ellipse Canvas.Left="32" Canvas.Top="4" Fill="Orange" /> /Canvas> Image Canvas.Left="4" Canvas.Top="4" Source="Globe.png" Stretch="Fill" Height="48" Width="48" /> Image Canvas.Left="222" Canvas.Top="4" Source="Computer.png" Stretch="Fill" Height="48" Width="48" /> /Canvas>/UserControl>I made a Style targeting Ellipses to set the size and color of all dots. The three orange dots are made as three Ellipse controls placed on an inner Canvas named SlidingCanvas. The animation is made by changing the Left property of this canvas. The sliding canvas starts hidden behind the globe image and ends behind the PC image. Code-BehindThe code behind the UserControl is shown below: public partial class DownloadAnimationControl : UserControl { private int i; private double startPos; private DispatcherTimer timer; public DownloadAnimationControl() { i = 0; InitializeComponent(); startPos = Canvas.GetLeft(SlidingCanvas); timer = new DispatcherTimer(); timer.Interval = TimeSpan.FromMilliseconds(100); timer.Tick += new EventHandler(timer_Tick); } public void StartAnimation() { timer.Start(); } public void StopAnimation() { timer.Stop(); } private void timer_Tick(object sender, EventArgs e) { i++; if (i 16) { Canvas.SetLeft(SlidingCanvas, Canvas.GetLeft(SlidingCanvas) + 14); } else { i = 0; Canvas.SetLeft(SlidingCanvas,

If you’re looking for a way to take screenshot of a web page or element using JavaScript, then this blog is for you. In this blog, you’ll learn how to take screenshots and download them easily in JavaScript using the html2canvas library.As you know, screenshots can be a valuable and vital part of web applications. Screenshots are used for multiple purposes in the application. Companies like Google use them in their feedback form while getting feedback or report from users.Let’s talk about how to use html2canvas library to take screenshots and download the screenshots directly on the user’s device. Remember, html2canvas will be used to capture screenshots only. To download screenshots, there will use JavaScript canvas.To take a screenshot and download it using html2canvas & JavaScript, follow the given steps line by line.Create an index.html file and paste the given codes. If you look carefully at the code, I’ve imported the html2canvas library before the closing of . There are two buttons too, which are used to take screenshots and download the screenshot. Take Screenshot using JavaScript Take Screenshot & Download it This is a dummy list 1 This is a dummy list 2 This is a dummy list 3 This is a dummy list 4 Dummy Link Click the specific button to take screenshot or download the screenshot of this page. Take Screenshot Take Screenshot & Download Once you do the above step. Paste the given codes before the closing of . const srcElement = document.querySelector("body"), btns = document.querySelectorAll("button"); btns.forEach(btn => { // looping through each btn // adding click event to each btn btn.addEventListener("click", () => { // creating canvas of element using html2canvas html2canvas(srcElement).then(canvas => { // adding canvas/screenshot to the body if(btn.id === "take-src-only") { return document.body.appendChild(canvas); } // downloading canvas/screenshot const a = document.createElement("a"); a.href = canvas.toDataURL(); a.download = "screenshot.jpg"; a.click(); }); }); });That’s all, now you are ready to take a screenshot of the web page and download it. In the codes, I’ve passed the body as a screenshot element, but you can pass any element and capture a screenshot of it according to your requirement.Conclusionhtml2canvas doesn’t actually take a screenshot of the web page. It builds a representation of the page based on the properties it reads from the DOM and returns the canvas as an image. So, the image it returns may not be 100% accurate as compared to the original page. Read more about the html2canvas library.If you don’t know, you can also capture screenshots with pure JavaScript. For more, read this blog: How to Take Screenshots in Vanilla JavaScript.

Is letting you know that the canvas is transparent instead of white. When creating drawings you do not want extra canvas around your drawing. Create your drawing in the upper left hand corner and drag the bottom right hand corner to remove extra canvas.Download DrawingUse the File menu to download your drawing. Choose “Download as…” from the menu and download it as a PNG image. If you have any transparency (checked background showing) in the drawing the PNG will preserve the transparency. Note that once you download the drawing, the PNG file will NOT update as edits are made to the drawing.Publish to the WebIf you wish to embed or link to your drawing instead of downloading the drawing use the File menu and choose “Publish to the web…”Click on “Embed” and click the blue “Publish” button. This will give you an embed code you can copy and paste into your website HTML to display the image.

The Tool Options panel and select a shape. To view other libraries, select a different library from the Shapes drop-down. Double-click a shape to select it. Drag within the image to create the shape boundary andmove it to the desired location in the image. Click the Commit button , or press Enter to finish the cropping. To cancel the cropping operation, click the Cancel button or press Esc. Change the size of the canvas The canvas is the workspace around an existing image, within the image window. It is the full editable area of an image. You can increase or decrease the size of the canvas, on any side of an image. Added canvas appears in the currently selected background color on the Background layer (by default), or selected canvas extension color from the Canvas size window. In other layers, the added canvas is transparent. Increasing the size of the canvas makes room for a coloredborder. Choose Image > Resize > Canvas Size. In the Width and Height fields, enter the full dimensions of the new canvas. Choose the units of measurement you want from the adjacent drop-downs. Select Relative, and enter the amount by which you want to increase or decrease the size of the canvas. Enter a negative number to decrease the size of the canvas. Use this option to increase the canvas by a specified amount, such as 2 inches on each side. Click an arrow on the Anchor icon to indicate the position you want on the canvas. To change the color of the added canvas, choose an option from the Canvas Extension Color menu and click OK. Straighten an image Camera shake can cause an image to be improperly aligned. For example, the horizon in the picture of a sunset may not be perfectly horizontal. In Photoshop Elements, you can realign the photo to cause the horizon to be perfectly horizontal. You can use the Straighten tool (P) to realign an image vertically or horizontally. You can also choose to automatically resize or crops the canvas to accommodate straightening of the image. In Quick mode, with the Straighten tool (P) active, simply draw a line along the horizon (when visible). When not visible, draw a line that you consider must represent the horizontal axis of the photo.The photo is straightened, and depending on the option you chose, any empty edges created are automatically filled. Manually straighten an image in Expert mode Select the Straighten tool. Choose from the available option buttons: Grow Or Shrink Canvas To Fit Resizes the canvas to fit the rotated image. Straightening causes corners of the image to fall outside the current canvas. The straightened image contains areas of blank background, but no pixels are clipped. Crop To Remove Background Crops the image to remove any blank background area that becomes visible after straightening. Some pixels are clipped. Crop To Original Size Keeps the canvas the same size as the original image. The straightened image includes areas of blank background and