superimage

SuperImage

The package provides some useful structures and functions for working with images. Apply effects such as blur or negative color to an image with a well-performing tool.

Index

• SuperImage
  • Index
  • Getting Started
    • Installation
    • Quick start
  • Examples
  • References
    • About SuperImage
    • Using GetByURL
    • Using GetByFile
    • Using Decode
    • Using Encode
    • Using Negative
    • Using Flip
    • Using Reflect
    • Using Blur
  • Interest links

Getting Started

Installation

To install SuperImage package, you need solve the following issues:

1. Install Go (version 1.18.+ recommended).

2. Get the package using go modules:

    go get github.com/nicolito/superimage/v2

1. Import it in your code:

    import "github.com/nicolito128/superimage/v2"

Quick start

project/main.go:

package main

import (
    "bytes"
	"os"

    "github.com/nicolito128/superimage"
)

func main() {
    img, err := superimage.GetByURL("https://go.dev/blog/gopher/gopher.png")
    if err != nil {
        panic(err)
    }

    // Buffer for store the image data
    buf := new(bytes.Buffer)
    // Encode writes the image into the buffer
    // gopher is ".png", so options can be nil
    err = superimage.Encode(buf, img, nil, nil)
    if err != nil {
        panic(err)
    }

    // Writing the cute gopher
    os.WriteFile("gopher.png", buf.Bytes(), 0666)
}

Examples

You have some good examples on how to use the package in the examples/ folder.

References

About SuperImage

SuperImage is an Go struct, it can be used as any Image from the std image package because it's an Image composition. You can create a new SuperImage with the New(...) function.

func main() {
    rec := image.Rectangle{image.Point{0, 0}, image.Point{500, 500}}
    boringImg := image.NewRGBA(rec)
    superImg := superimage.New(boringImg, "png")

    println(superImg.Bounds())
}

Using GetByURL

Get a new SuperImage with an URL.

func main() {
    // Getting a new SuperImage with a link
    urlImg, err := superimage.GetByURL("https://awesomeurl.com/image.png")
    if err != nil {
        panic(err)
    }

    println(urlImg.Bounds())
}

Using GetByFile

Get a new SuperImage with a project file image.

func main() {
    // Getting a new SuperImage with a file
    fileImg, err := superimage.GetByFile("./folder/cool_image.jpg")
    if err != nil {
        panic(err)
    }

    println(fileImg.Bounds())
}

Using Decode

Decodes an reader on a new SuperImage.

func main() {
    file, _ := os.Open("./examples/gopher/gopher.png")
	i, err := superimage.Decode(file, "png")
    if err != nil {
        panic(err)
    }

	println(i.Bounds())
}

Using Encode

Encodes a writer on a new SuperImage.

func main() {
    fileImg, err := superimage.GetByFile("./folder/cool_image.jpg")
    if err != nil {
        panic(err)
    }

    buf := new(bytes.Buffer)
	err = superimage.Encode(buf, img, nil, nil)
	if err != nil {
		panic(err)
	}

    println(len(buf.Bytes()))
}

Using Negative

Inverts the colors of an image.

func main() {
    img, err := superimage.GetByURL("https://awesomeurl.com/image.png")
    if err != nil {
        panic(err)
    }

    // Inverting image colors
    neg := superimage.Negative(img)

    // Saving
    buf := new(bytes.Buffer)
    err = superimage.Encode(buf, neg, nil, nil)
    if err != nil {
        panic(err)
    }

    ioutil.WriteFile("./negative.png", buf.Bytes(), 0666)
}

Using Flip

Turn an image upside down.

func main() {
    img, err := superimage.GetByURL("https://awesomeurl.com/image.png")
    if err != nil {
        panic(err)
    }

    // Flipping image
    flipped := superimage.Flip(img)

    // Saving
    buf := new(bytes.Buffer)
    err = superimage.Encode(buf, flipped, nil, nil)
    if err != nil {
        panic(err)
    }

    ioutil.WriteFile("./flipped.png", buf.Bytes(), 0666)
}

Using Reflect

Reflects an image vertically.

func main() {
    img, err := superimage.GetByURL("https://awesomeurl.com/image.png")
    if err != nil {
        panic(err)
    }

    // Reflecting image
    reflect := superimage.Reflect(img)

    // Saving
    buf := new(bytes.Buffer)
    err = superimage.Encode(buf, reflect, nil, nil)
    if err != nil {
        panic(err)
    }

    ioutil.WriteFile("./reflect.png", buf.Bytes(), 0666)
}

Using Blur

Blur an image by a given radio.

func main() {
    img, err := superimage.GetByURL("https://awesomeurl.com/image.png")
    if err != nil {
        panic(err)
    }

    // Blur
    blurred, err := superimage.Blur(img, 2)
    if err != nil {
        panic(err)
    }

    // Saving
    buf := new(bytes.Buffer)
    err = superimage.Encode(buf, blurred, nil, nil)
    if err != nil {
        panic(err)
    }

    ioutil.WriteFile("./blurred.png", buf.Bytes(), 0666)
}

Interest links

• Go image standard library