An image cropper for Angular
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README.md

Image cropper for Angular

example

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 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'} ) );

      });
    }
  });
}