ngx-image-cropper

What is ngx-image-cropper?

The ngx-image-cropper is an Angular library that provides a highly customizable image cropping tool. It allows users to crop images in various shapes and sizes, and offers a range of features to enhance the image cropping experience.

What are ngx-image-cropper's main functionalities?

Basic Image Cropping

This feature allows users to crop images while maintaining a specific aspect ratio. The cropped image is emitted in the specified format (e.g., PNG).

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

Free Aspect Ratio Cropping

This feature allows users to crop images without maintaining a fixed aspect ratio, providing more flexibility in selecting the crop area.

<image-cropper [imageChangedEvent]="imageChangedEvent" [maintainAspectRatio]="false" format="jpeg" (imageCropped)="imageCropped($event)"></image-cropper>

Round Cropping

This feature allows users to crop images in a circular shape, which is useful for profile pictures and other round image requirements.

<image-cropper [imageChangedEvent]="imageChangedEvent" [maintainAspectRatio]="true" [aspectRatio]="1 / 1" [roundCropper]="true" format="png" (imageCropped)="imageCropped($event)"></image-cropper>

Image Rotation

This feature allows users to rotate the image before cropping, ensuring the image is properly oriented.

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

Other packages similar to ngx-image-cropper

cropperjs

Cropper.js is a JavaScript image cropping library that provides a rich set of features for cropping images. It is highly customizable and can be used with various frameworks, including Angular. Compared to ngx-image-cropper, Cropper.js offers more advanced features and greater flexibility but requires more setup and integration effort.

react-image-crop

React Image Crop is a library specifically designed for React applications. It provides a simple and easy-to-use interface for cropping images. While it offers similar functionalities to ngx-image-cropper, it is tailored for React rather than Angular, making it a better choice for React developers.

vue-cropper

Vue Cropper is a Vue.js component for image cropping. It offers a range of features similar to ngx-image-cropper but is designed for use with Vue.js. It provides a seamless integration with Vue applications and is a good alternative for developers working with the Vue framework.

README

Image cropper for Angular

StackBlitz

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()"
    (cropperReady)="cropperReady()"
    (loadImageFailed)="loadImageFailed()"
></image-cropper>

<img [src]="croppedImage" />

And add this to your ts file:

import { ImageCroppedEvent } from 'ngx-image-cropper';

export class YourComponent {
    imageChangedEvent: any = '';
    croppedImage: any = '';
    
    fileChangeEvent(event: any): void {
        this.imageChangedEvent = event;
    }
    imageCropped(event: ImageCroppedEvent) {
        this.croppedImage = event.base64;
    }
    imageLoaded() {
        // show cropper
    }
    cropperReady() {
        // cropper ready
    }
    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, imageBase64 or imageFile 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)
imageFile	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	base64	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
aspectRatio	number	1 / 1	The width / height ratio (e.g. 1 / 1 for a square, 4 / 3, 16 / 9 ...)
maintainAspectRatio	boolean	true	Keep width and height of cropped image equal according to the aspectRatio
containWithinAspectRatio	boolean	false	When set to true, padding will be added around the image to make it fit to the aspect ratio
resizeToWidth	number	0 (disabled)	Cropped image will be resized to this width (in px)
resizeToHeight	number	0 (disabled)	Cropped image will be resized to this height (in px) (will be ignored if resizeToWidth is set)
cropperMinWidth	number	0 (disabled)	The cropper cannot be made smaller than this number of pixels in width (relative to original image's size) (in px)
cropperMinHeight	number	0 (disabled)	The cropper cannot be made smaller than this number of pixels in height (relative to original image's size) (in px) (will be ignored if maintainAspectRatio is set)
onlyScaleDown	boolean	false	When the resizeToWidth is set, enabling this option will make sure smaller images are not scaled up
cropper	CropperPosition		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.
backgroundColor	string		Use this to set a backgroundColor, this is useful if you upload an image of a format with transparent colors and convert it to 'jpeg' or 'bmp'. The transparent pixels will then become the set color or the default value. Enter a color HashCode or one of known HTML color names (https://www.w3schools.com/tags/ref_colornames.asp).

Outputs

Name	Type	Description
imageCropped	ImageCroppedEvent	Emits an ImageCroppedEvent each time the image 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)

Transformations

Property	Type	Description
rotation	number	0=No Rotation, 1=90°, 2=180°, 3=270°
flipH	boolean	Flipped Horizontally
flipV	boolean	Flipped Vertically

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
offsetImagePosition	CropperPosition	Position of the cropper when it was cropped relative to the original image size without padding when containWithinAspectRatio is true
transform	Transformations	Rotation and Flip State

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'} ) );

      });
    }
  });
}