First of all, I'm very new to javascript. I'm trying to develop a javascript function which takes an image and returns a cropped version of that image. By looking around on google I've found that I probably need to use a canvas in some way to accomplish this task. But does that mean I have to display the image on my page?
I've also looked at different javascript image processing libraries for a similar function, for example Pixastic's Crop, but I have no idea how to use it to solve my particular problem. So now I'm turning to you guys for help. Please guide me in the right direction!
Thanks!
Pixastic's Crop solution seems easy to implement and uses the canvas. It would do the job as long as you don't need to support Internet Explorer 7 or 8.
Otherwise, you can simply use CSS overflow:hidden; to do a client side cropping.
Pixastic Solution: http://www.pixastic.com/lib/docs/actions/crop/, check out the Example Code tab.
Here is a working example for Pixastic and the CSS solutions: http://jsfiddle.net/EB6P7/1/
I used the jQuery plugin for Pixastic.
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If you don't need to save the image on the server side I recommand using the CSS solution as it doesn't rely on Javascript and achieve the same result as Pixastic.
If there's anything you don't understand, ask me as I don't know your level in HTML/CSS.
Well if your problem is only cropping and not saving the cropped image, the simplest solution I would say is to position the image using CSS inside a div and show only the cropped area.
If you want to save then I wish you need to use some library on the server side to crop and save
Maybe the CSS Clipping feature is a solution for you?
#someImage
{
clip:rect(50px 100px 130px auto);
}
Related
I am building a web application using Parse as my backend.
Part of the signup process involves the user uploading and cropping an image before I pass it along to my database (the picture is part of the user profile, similar to what you would do on Twitter).
I have figured out the uploading parts (both to the browser and then to the database), but I am not as confident with allowing the user to manipulate the image.
Most solutions involve using jCrop to achieve a result similar to the example here (although without the PHP).
Given that I am using Parse, is there a client-side solution that works better? How might a solution look?
Thanks!
Jesse
Basically I would go this way:
Load your image into a <canvas>
Crop the Image: http://www.html5canvastutorials.com/tutorials/html5-canvas-image-crop/
Save a image from the canvas: http://www.html5canvastutorials.com/advanced/html5-canvas-save-drawing-as-an-image/
Here is a very good tutorial.
Disclaimer: I haven't tested this yet, but I heard that this way work.
Also use background-size:cover; or background-size:contain; to get around nasty dimension problems.
You can able to crop an image using HTML canvas, but it involves lots of codes, Consider using Cropperjs, It's a pure javascript library for cropping images. Here client-side image cropping by cropperjs is the working example.
Is there a way to manipulate an image(crop) using javascript in IE? I know that I can do this with some ActiveX controls. But is there a pure javascript way? May be with filters are any special api provided by Internet Explorer?
It depends upon what you're trying to do. You can use a containing div with overflow set to hidden and a constrained size to clip off any portion of an image and only show a desired crop. If the geometry is known ahead of time, this can be done with pure HTML/CSS. If you need to calculate the size, then sizes, positions and CSS properties can be set with javascript.
Demo: http://jsfiddle.net/jfriend00/QsHy7/
You can use Jcrop with the jQuery library. (info, download page)
You can also take a look at iCropper: http://github.com/supnate/icropper which is a pure javascript image cropping solution. It doesn't depend on any library which makes it fast, light-weight and easy to integrate.
I'm trying to build an interface for the user, so he can choose or pick colored eyes, skin, etc., of a model. I'm really on my way with divs and CSS. I'm using Ajax for loading images into the divs.
My problem is that I need to offer a option to the user so he can save the image as a JPEG or PNG file.
Looking around, I found canvas HTML5 stuff on Stack Overflow, but it's not compatible with Internet Explorer,
Create an Image of a DIV in JavaScript (GIF/PNG)
How can I save div as image at client side where div contains one or more than one HTML5 canvas elements?
I need help to find something compatible with all browsers.
I also found this JavaScript code:
button = document.createElement("img");
button.src = "http://example.com/livechart.gif?interval=15"
But I don't know much about the createElement method.
I know CSS, but JavaScript is beyond my knowledge.
You cannot do this on the browser, you must do it on the server.
see: Convert web page to image
You want to take screenshot of the browser? Well, there are lot of ways you could try, but all of them would be browser-specific. The most reliable would be to just tell the user to make a screenshot with the OS. On a Mac it's Command-Shift-4, then space; on a PC, it it's ALT-PrtScr, I think.
I believe you could do that with HTML canvas and some JavaScript: Canvas2Image : Saving Canvas data to image file.
I'm trying to dynamically make a kaleidoscope pattern from a source image.
You can see an example in Flash here: http://www.maegpai.com/mademyshirt/tool/ (click an image to start).
I want to create the same effect using either HTML Canvas, CSS (masking) or ImageMagick and PHP.
What would be the best way to create something like this besides Flash?
I'm not concerned about older browsers, if I can get this to work in Safari and Chrome that will be enough.
Here is a CSS one: http://bl.ocks.org/abernier/raw/9070122/ code can be found here: http://bl.ocks.org/abernier/9070122/
If you want it done quickly with the least amount of work on your part, use ImageMagick and PHP, the script is already written for you.
If you want to show off your mad skillz, I'd go for CSS (masking). That seems difficult to me.
If you want to get attention, go with HTML5 Canvas. Everyone thinks it's cool.
We currently have a system for cropping images that uses jCrop on the front-end, and System.Drawing in .NET on the backend - this works very well, but now we need to introduce image rotation. Only 90 degree angles are needed, and jQuery.Rotate works fine in isolation, but I would like to combine these two jQuery plugins gracefully. Do you have any experience in this area? Are there "shake & bake" solutions?
I suggest rotating the image server side. You really can't combine jCrop with a rotated image, since a CSS-based method would 'lie' about the width and height.
It can be extremely fast. Your UI would simply add 'rotate=90' to the image querystring when the button was clicked, and the image would reload.
Here's a very simple example of using jCrop and querystring-based resizing.
Take a look at the demo page to see how responsive it is - adding the rotate command would only take a few lines of javascript. If you need it, I could upload a sample of how to combine them.
I know this is an old question but, have you checked this jQuery plugin called CropIt?
The demo looks very good and you have zoom, crop and rotate in the same plugin, no backend code required.
Hope this helps.
Since the two plugin-ins operate in very different ways, I don't think you can readily combine the two. jCrop simply allows you to define a rectangular marquee over an image. Rotation, on the other hand, either uses <canvas> to actually rotate the image or the DXImageTransform filter to show it rotated (not actually rotating the source image.)
I think jQuery pipe-lining is the answer for any jQuery plugin
for example:
$("image").rotate(foo).crop(foo);
you may try jquery CropZoom:
http://plugins.jquery.com/project/CropZoom
Demo and downloads here:
http://www.gastonrobledo.com.ar/cropzoom/index.html