Description

NestJS module for simple and flexible image resizing. Uses the gm library and implements a user-friendly interface for resizing and converting images.

Features

• Format support: jpg, jpeg, png, tif, tiff (other formats were not tested)
• Resize images while maintaining aspect ratio
• Automatic image rotation by exif metadata
• Converting images to supported formats
• Additional settings for resizing images

Installation

Install this library

npm install nestjs-img-resize

The library depends on gm, so the graphicsmagick and imagemagick libraries need to be installed

apt-get install -y graphicsmagick imagemagick

or

brew install imagemagick
brew install graphicsmagick

Usage

Connect the module to your project

@Module({
  imports: [
    NestjsImgResizeModule,
  ],
})
export class AppModule {
}

Inject ImgResizeService into controller or your service

@Injectable()
export class Myservice {
  constructor(protected imgResizeService: ImgResizeService) {
  }
}

Image conversion method

Converting an image to a specific format

convert(image: Buffer, convertConfig: ImgConvertConfig):Promise<Buffer>;

Image resize method

Resize image by configuration

resize(image: Buffer, resizeConfig: ImgResizeConfig): Promise<ImgResizeResponse>;

Image bulk resize method

Resize image by bulk configuration, and the result is images in several sizes.

resizeBulk(image: Buffer, resizeConfig: ImgResizeConfig[]): Promise<ImgResizeResponse[]>

Get image dimension

getImgDimension(buffer: Buffer): Promise<ImgDimension>

Interfaces

ImgConvertConfig

| Prop | Type | Description | |---------------- |------------ |---------------------------------------------------------------------------------------------------------------------------- | | autoExifRotate | boolean | Allow to automatically rotate the image based on exif metadata, default - false | | outType | ImageTypes | Output Image Format, default jpeg | | fillAlpha | string | Fill the alpha channel with a specific color, useful when converting a format with an alpha channel to a format without it |

ImgResizeConfig

extends ImgConvertConfig

| Prop | Type | Description | |-------------- |-------------- |-------------------------------------------------------------------------------------------------------- | | width | number | Resized image width, required | | height | number | Resized image height, required | | exact | boolean | If true then the output image size will have the exact size specified in the configuration, by default false - resizing takes into account the aspect ratio of the image | | allowStretch | allowStretch | Stretch the image if it is smaller than the specified size, only works if exact = false, default false | | sizeName | string | Size name, for identify resized result, optional | | autoExifRotate | boolean | Allow to automatically rotate the image based on exif metadata, default - false | | outType | ImageTypes | Output Image Format, default jpeg | | fillAlpha | string | Fill the alpha channel with a specific color, useful when converting a format with an alpha channel to a format without it |

Benchmark

npm run benchmark

Benchmark results

The results depend on the characteristics of the machine on which the test is performed.
My results on Intel Core i5-10300H CPU @ 2.50GHz × 8, 15,5 GiB, Ubuntu 20.04.2 LTS

v1.0.0

Resize jpg 1920x1080 to 500x281 --> 9.81338447508557 ops/sec | Samples: 49
Resize png 1920x1080 to 500x281 --> 4.821842038356058 ops/sec | Samples: 27
Convert 650x434 png to jpg --> 28.200684305778598 ops/sec | Samples: 68
Convert 650x434 tiff to jpg --> 25.820336860905076 ops/sec | Samples: 45

Tests

npm run test:e2e

License

MIT