Image cropper for Angular

Installation

npm install ngx-image-cropper --save

Example usage:

Add the ImageCropperModule to the imports of the module which will be using the Image Cropper.

import { NgModule } from '@angular/core';
import { ImageCropperModule } from 'ngx-image-cropper';

@NgModule({
    imports: [
        ...
        ImageCropperModule
    ],
    declarations: [
        ...
    ],
    exports: [
        ...
    ],
    providers: [
        ...
    ]
})
export class YourModule {
}

Add the element to your HTML:

<input type="file" (change)="fileChangeEvent($event)" />

<image-cropper
    [imageChangedEvent]="imageChangedEvent"
    [maintainAspectRatio]="true"
    [aspectRatio]="4 / 3"
    [resizeToWidth]="128"
    format="png"
    (imageCropped)="imageCropped($event)"
    (imageLoaded)="imageLoaded()"
    (loadImageFailed)="loadImageFailed()"
></image-cropper>

<img [src]="croppedImage" />

And add this to your ts file:

imageChangedEvent: any = '';
croppedImage: any = '';

fileChangeEvent(event: any): void {
    this.imageChangedEvent = event;
}
imageCropped(event: ImageCroppedEvent) {
    this.croppedImage = event.base64;
}
imageLoaded() {
    // show cropper
}
loadImageFailed() {
    // show message
}

When you choose a file from the file input, it will trigger fileChangeEvent. That event is then passed to the image cropper through imageChangedEvent which will load the image into the cropper. Everytime you release the mouse, the imageCropped event will be triggerd with the cropped image as a Base64 string in its payload.

API

All inputs are optional. Either the imageChangedEvent or imageBase64 should be set to load an image into the cropper.

Inputs

Name	Type	Default	Description
`imageChangedEvent`	FileEvent		The change event from your file input (set to `null` to reset the cropper)
`imageFileChanged`	Blob(File)		The file you want to change (set to `null` to reset the cropper)
`imageBase64`	string		If you don't want to use a file input, you can set a base64 image directly and it will be loaded into the cropper
`format`	string	png	Output format (png, jpeg, webp, bmp, ico) (not all browsers support all types, png is always supported, others are optional)
`outputType`	string	both	Output type ('base64', 'file' or 'both'). Converting the image to a Blob can be quite a heavy operation. With this option, you could choose to only get the base64 which will improve the speed of cropping significantly
`maintainAspectRatio`	boolean	true	Keep width and height of cropped image equal according to the aspectRatio
`aspectRatio`	number	1 / 1	The width / height ratio (e.g. 1 / 1 for a square, 4 / 3, 16 / 9 ...)
`resizeToWidth`	number	0 (disabled)	Cropped image will be resized to this width (in px)
`cropperMinWidth`	number	0 (disabled)	The cropper cannot be made smaller than this number of pixels (relative to original image's size) (in px)
`onlyScaleDown`	boolean	false	When the `resizeToWidth` is set, enabling this option will make sure smaller images are not scaled up
`cropper`	{ x1: number, y1: number, x2: number, y2: number }		To be able to overwrite the cropper coordinates, you can use this input. Create a new object of type `CropperPosition` and assign it to this input. Make sure to create a new object each time you wish to overwrite the cropper's position and wait for the `cropperReady` event to have fired.
`roundCropper`	boolean	false	Set this to true for a round cropper. Resulting image will still be square, use `border-radius: 100%` on resulting image to show it as round.
`imageQuality`	number	92	This only applies when using jpeg or webp as output format. Entering a number between 0 and 100 will determine the quality of the output image.
`autoCrop`	boolean	true	When set to true, the cropper will emit an image each time the position or size of the cropper is changed. When set to false, you can call the crop method yourself (use @ViewChild to get access to the croppers methods).
`alignImage`	'left' or 'center'	'center'	Use this to align the image in the cropper either to the left or center.

Outputs

Name	Type	Description
`imageCropped`	ImageCroppedEvent	Emits an ImageCroppedEvent each time the image is cropped
(DEPRECATED) `imageCroppedBase64`	string	Emits a Base64 string of the cropped image each time it is cropped
(DEPRECATED) `imageCroppedFile`	File	Emits the cropped image as a file each time it is cropped
`imageLoaded`	void	Emits when the image was loaded into the cropper
`cropperReady`	void	Emits when the cropper is ready to be interacted
`startCropImage`	void	Emits when the component started cropping the image
`loadImageFailed`	void	Emits when a wrong file type was selected (only png, gif and jpg are allowed)

Methods

To gain access to the image cropper's methods use @ViewChild(ImageCropperComponent) imageCropper: ImageCropperComponent;

Name	Returns	Description
`rotateLeft`	void	Rotates the image to the left
`rotateRight`	void	Rotates the image to the right
`flipHorizontal`	void	Flips the image horizontally
`flipVertical`	void	Flips the image vertically
`crop`	ImageCroppedEvent (when `outputType` is `base64`) or Promise<ImageCroppedEvent> (when `outputType` is `file` or `both`))	Crops the source image to the current cropper position. Accepts an output type as an argument, default is the one given in the `outputType` input (`base64`, `file` or `both`). Be sure to set `autoCrop` to `false` if you only wish to use this function directly.

Interfaces

CropperPosition

Property	Type	Description
x1	number	X position of first coordinate (in px)
y1	number	Y position of first coordinate (in px)
x2	number	X position of second coordinate (in px)
y2	number	Y position of second coordinate (in px)

ImageCroppedEvent

Property	Type	Description
base64	string	Base64 string of the cropped image
file	Blob(File)	Blob of the cropped image
width	number	Width of the cropped image
height	number	Height of the cropped image
cropperPosition	CropperPosition	Position of the cropper when it was cropped relative to the displayed image size
imagePosition	CropperPosition	Position of the cropper when it was cropped relative to the original image size

Polyfill for IE and Edge

If you wish to use the file output, you'll need to polyfill the toBlob method of the HTML Canvas for IE and Edge.

if (!HTMLCanvasElement.prototype.toBlob) {
  Object.defineProperty(HTMLCanvasElement.prototype, 'toBlob', {
    value: function (callback, type, quality) {
      var dataURL = this.toDataURL(type, quality).split(',')[1];
      setTimeout(function() {

        var binStr = atob( dataURL ),
            len = binStr.length,
            arr = new Uint8Array(len);

        for (var i = 0; i < len; i++ ) {
          arr[i] = binStr.charCodeAt(i);
        }

        callback( new Blob( [arr], {type: type || 'image/png'} ) );

      });
    }
  });
}

stemarco/ngx-image-cropper