gocaptcha

README

gocaptcha

一个简单的Go语言实现的验证码

图片实例

简介

基于Golang实现的图片验证码生成库，可以实现随机字母个数，随机直线，随机噪点等。可以设置任意多字体，每个验证码随机选一种字体展示。

实例

使用：

	go get github.com/lifei6671/gocaptcha

使用的类库

	go get github.com/golang/freetype
	go get github.com/golang/freetype/truetype
	go get golang.org/x/image

代码

具体实例可以查看example目录，有生成的验证码图片。

	
func Get(w http.ResponseWriter, r *http.Request) {
	captchaImage := gocaptcha.New(dx, dy, gocaptcha.RandLightColor())
	err := captchaImage.
		DrawBorder(gocaptcha.RandDeepColor()).
		DrawNoise(gocaptcha.NoiseDensityHigh, gocaptcha.NewTextNoiseDrawer(gocaptcha.DefaultDPI)).
		DrawNoise(gocaptcha.NoiseDensityLower, gocaptcha.NewPointNoiseDrawer()).
		DrawLine(gocaptcha.NewBezier3DLine(), gocaptcha.RandDeepColor()).
		DrawText(gocaptcha.NewTwistTextDrawer(gocaptcha.DefaultDPI, gocaptcha.DefaultAmplitude, gocaptcha.DefaultFrequency), gocaptcha.RandText(4)).
		DrawLine(gocaptcha.NewBeeline(), gocaptcha.RandDeepColor()).
		//DrawLine(gocaptcha.NewHollowLine(), gocaptcha.RandLightColor()).
		DrawBlur(gocaptcha.NewGaussianBlur(), gocaptcha.DefaultBlurKernelSize, gocaptcha.DefaultBlurSigma).
		Error
	
	if err != nil {
		fmt.Println(err)
	}
	
	_ = captchaImage.Encode(w, gocaptcha.ImageFormatJpeg)
}

// 初始化字体
func init() {
	err := gocaptcha.SetFontPath("../fonts/")
	if err != nil {
		panic(err)
	}
}

Documentation

Index

• Constants
• Variables
• func ColorToRGB(colorVal int) color.RGBA
• func RandColor() color.RGBA
• func RandDeepColor() color.RGBA
• func RandLightColor() color.RGBA
• func RandText(num int) string
• func Random(min int64, max int64) float64
• func SetFontPath(fontDirPath string) error
• func SetFonts(fonts ...string) error
• type BlurDrawer
  • func NewGaussianBlur() BlurDrawer
• type CaptchaImage
  • func New(width int, height int, bgColor color.RGBA) *CaptchaImage
  • func (captcha *CaptchaImage) DrawBlur(drawer BlurDrawer, kernelSize int, sigma float64) *CaptchaImage
  • func (captcha *CaptchaImage) DrawBorder(borderColor color.RGBA) *CaptchaImage
  • func (captcha *CaptchaImage) DrawLine(drawer LineDrawer, lineColor color.Color) *CaptchaImage
  • func (captcha *CaptchaImage) DrawNoise(complex NoiseDensity, noiseDrawer NoiseDrawer) *CaptchaImage
  • func (captcha *CaptchaImage) DrawText(textDrawer TextDrawer, text string) *CaptchaImage
  • func (captcha *CaptchaImage) Encode(w io.Writer, imageFormat ImageFormat) error
• type FontFamily
  • func NewFontFamily() *FontFamily
  • func (f *FontFamily) AddFont(fontFile string) error
  • func (f *FontFamily) AddFontPath(dirPath string) error
  • func (f *FontFamily) Random() (*truetype.Font, error)
• type ImageFormat
• type LineDrawer
  • func NewBeeline() LineDrawer
  • func NewBezier3DLine() LineDrawer
  • func NewBezierLine() LineDrawer
  • func NewCurveLine() LineDrawer
  • func NewHollowLine() LineDrawer
• type NoiseDensity
• type NoiseDrawer
  • func NewPointNoiseDrawer() NoiseDrawer
  • func NewTextNoiseDrawer(dpi float64) NoiseDrawer
• type TextDrawer
  • func NewTextDrawer(dpi float64) TextDrawer
  • func NewTwistTextDrawer(dpi float64, amplitude float64, frequency float64) TextDrawer

Constants

const (
	// DefaultDPI 默认的dpi
	DefaultDPI = 72.0
	// DefaultBlurKernelSize 默认模糊卷积核大小
	DefaultBlurKernelSize = 2
	// DefaultBlurSigma 默认模糊sigma值
	DefaultBlurSigma = 0.65
	// DefaultAmplitude 默认图片扭曲的振幅
	DefaultAmplitude = 20
	//DefaultFrequency 默认图片扭曲的波频率
	DefaultFrequency = 0.05
)

Variables

var (
	ErrNilCanvas = errors.New("canvas is nil")
	ErrNilText   = errors.New("text is nil")
)

var DefaultFontFamily = NewFontFamily()

var ErrNoFontsInFamily = os.ErrNotExist

var TextCharacters = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")

Functions

func ColorToRGB

func ColorToRGB(colorVal int) color.RGBA

ColorToRGB 颜色代码转换为RGB input int output int red, green, blue.

func RandColor

func RandColor() color.RGBA

RandColor 生成随机颜色.

func RandDeepColor

func RandDeepColor() color.RGBA

RandDeepColor 随机生成深色系.

func RandLightColor

func RandLightColor() color.RGBA

RandLightColor 随机生成浅色.

func RandText

func RandText(num int) string

RandText 生成随机字体.

func Random

func Random(min int64, max int64) float64

Random 生成指定大小的随机数.

func SetFontPath

func SetFontPath(fontDirPath string) error

SetFontPath sets the default font family from a directory

func SetFonts

func SetFonts(fonts ...string) error

SetFonts sets the default font family

Types

type BlurDrawer

type BlurDrawer interface {
	DrawBlur(canvas draw.Image, kernelSize int, sigma float64) error
}

func NewGaussianBlur

func NewGaussianBlur() BlurDrawer

type CaptchaImage

type CaptchaImage struct {
	Complex int
	Error   error
	// contains filtered or unexported fields
}

func New

func New(width int, height int, bgColor color.RGBA) *CaptchaImage

New 新建一个图片对象

func (*CaptchaImage) DrawBlur

func (captcha *CaptchaImage) DrawBlur(drawer BlurDrawer, kernelSize int, sigma float64) *CaptchaImage

DrawBlur 对图片进行模糊处理

func (*CaptchaImage) DrawBorder

func (captcha *CaptchaImage) DrawBorder(borderColor color.RGBA) *CaptchaImage

DrawBorder 画边框.

func (*CaptchaImage) DrawLine

func (captcha *CaptchaImage) DrawLine(drawer LineDrawer, lineColor color.Color) *CaptchaImage

DrawLine 画直线.

func (*CaptchaImage) DrawNoise

func (captcha *CaptchaImage) DrawNoise(complex NoiseDensity, noiseDrawer NoiseDrawer) *CaptchaImage

DrawNoise 画噪点.

func (*CaptchaImage) DrawText

func (captcha *CaptchaImage) DrawText(textDrawer TextDrawer, text string) *CaptchaImage

DrawText 写字.

func (*CaptchaImage) Encode

func (captcha *CaptchaImage) Encode(w io.Writer, imageFormat ImageFormat) error

Encode 编码图片

type FontFamily

type FontFamily struct {
	// contains filtered or unexported fields
}

FontFamily is a font family that creates a new font family

func NewFontFamily

func NewFontFamily() *FontFamily

NewFontFamily creates a new font family with the given fonts

func (*FontFamily) AddFont

func (f *FontFamily) AddFont(fontFile string) error

AddFont adds a font to the family and returns an error if it fails

func (*FontFamily) AddFontPath

func (f *FontFamily) AddFontPath(dirPath string) error

AddFontPath adds all .ttf files from the given directory to the font family and returns an error if any

func (*FontFamily) Random

func (f *FontFamily) Random() (*truetype.Font, error)

Random returns a random font from the family

type ImageFormat

type ImageFormat int

ImageFormat 图片格式

const (
	ImageFormatPng ImageFormat = iota
	ImageFormatJpeg
	ImageFormatGif
)

type LineDrawer

type LineDrawer interface {
	DrawLine(canvas draw.Image, x image.Point, y image.Point, color color.Color) error
}

LineDrawer 实现划线的接口

func NewBeeline

func NewBeeline() LineDrawer

func NewBezier3DLine

func NewBezier3DLine() LineDrawer

NewBezier3DLine 3D效果的贝塞尔曲线

func NewBezierLine

func NewBezierLine() LineDrawer

NewBezierLine 贝塞尔曲线

func NewCurveLine

func NewCurveLine() LineDrawer

NewCurveLine 基于正弦函数的曲线

func NewHollowLine

func NewHollowLine() LineDrawer

NewHollowLine 空心线

type NoiseDensity

type NoiseDensity int

NoiseDensity is the complexity of captcha

const (
	NoiseDensityLower NoiseDensity = iota
	NoiseDensityMedium
	NoiseDensityHigh
)

type NoiseDrawer

type NoiseDrawer interface {
	// DrawNoise draws noise on the image
	DrawNoise(img draw.Image, density NoiseDensity) error
}

NoiseDrawer is a type that can make noise on an image

func NewPointNoiseDrawer

func NewPointNoiseDrawer() NoiseDrawer

NewPointNoiseDrawer returns a NoiseDrawer that draws noise points

func NewTextNoiseDrawer

func NewTextNoiseDrawer(dpi float64) NoiseDrawer

type TextDrawer

type TextDrawer interface {
	DrawString(canvas draw.Image, text string) error
}

TextDrawer is a text drawer interface.

func NewTextDrawer

func NewTextDrawer(dpi float64) TextDrawer

NewTextDrawer returns a new text drawer.

func NewTwistTextDrawer

func NewTwistTextDrawer(dpi float64, amplitude float64, frequency float64) TextDrawer

NewTwistTextDrawer returns a new text drawer with twist effect.