README
¶
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
Getting Started
Installation
To install SuperImage package, you need solve the following issues:
-
Install Go (version 1.22.+ recommended).
-
Get the package using go modules:
go get -u github.com/nicolito/superimage/v2
- 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
Documentation
¶
Index ¶
- Variables
- func Encode(w io.Writer, m image.Image, jpgOptions *jpeg.Options, gifOptions *gif.Options) error
- type SuperImage
- func Blur(img image.Image, radio int) (*SuperImage, error)
- func Decode(r io.Reader, format string) (*SuperImage, error)
- func Flip(img image.Image) *SuperImage
- func GetByFile(filename string) (*SuperImage, error)
- func GetByURL(link string) (*SuperImage, error)
- func Negative(img image.Image) *SuperImage
- func New(im image.Image, format string) *SuperImage
- func Opacity(img image.Image, op float64) (*SuperImage, error)
- func Reflect(img image.Image) *SuperImage
Constants ¶
This section is empty.
Variables ¶
var ErrInvalidOpacity = errors.New("opacity must be between 0 and 1")
var ErrNegativeRadio = errors.New("radio must be higher than 0")
Functions ¶
Types ¶
type SuperImage ¶
SuperImage is an image.Image implementation
func Blur ¶
func Blur(img image.Image, radio int) (*SuperImage, error)
Blur blurs an image by a given radio. If the radio is negative or bigger than the image's width or height, it returns an error. Radio 0 returns the original image without any change.
References: https://relate.cs.illinois.edu/course/cs357-f15/file-version/03473f64afb954c74c02e8988f518de3eddf49a4/media/00-python-numpy/Image%20Blurring.html | http://arantxa.ii.uam.es/~jms/pfcsteleco/lecturas/20081215IreneBlasco.pdf
func Decode ¶
func Decode(r io.Reader, format string) (*SuperImage, error)
Decode decodes an image from r using the specified format (png, jpg, jpeg, gif).
func Flip ¶
func Flip(img image.Image) *SuperImage
Flip inverts the image horizontally returning a new *SuperImage.
func GetByFile ¶
func GetByFile(filename string) (*SuperImage, error)
GetByFile gets an image from a current project file.
func GetByURL ¶
func GetByURL(link string) (*SuperImage, error)
GetByURL gets an image from an URL with an http GET request.
func Reflect ¶
func Reflect(img image.Image) *SuperImage
Reflect inverts the image vertically returning a new *SuperImage.
func (SuperImage) Format ¶
func (si SuperImage) Format() string
Source Files
Directories