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imageflow

package module
v0.0.0-...-ea10365 Latest Latest
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 Go to latest Published: Dec 7, 2022 License: AGPL-3.0 Imports: 6 Imported by: 0

README

Go Binding for Imageflow

WindowsMacosLinux

Quickly scale or modify images and optimize them for the web.

If the AGPLv3 does not work for you, you can get a commercial license on a sliding scale. If you have more than 1 server doing image processing your savings should cover the cost.

Docs are here

Installation

Imageflow dependents on libimageflow for image processing capabilities. libimageflow is available as the static and dynamic shared library on Linux and macOS. Currently libimageflow is available as a dynamic library for Windows. Prebuilt shared libraries are available here. Add libimageflowto OS path. Then it can be downloaded usinggo get.

$ go get github.com/imazen/imageflow-go

Usage

A simple go program to create two image of different size.

package main;

import (
	"io/ioutil"

	imageflow "github.com/imazen/imageflow-go"
)

func main(){
	step:=imageflow.NewStep()
	data,_:=step
	.Decode(imageflow.NewURL("https://jpeg.org/images/jpeg2000-home.jpg"))
	.Branch(func(step *imageflow.Steps){
		step
		.ConstrainWithin(200,200)
		.Encode(imageflow.NewFile("test_1.jpg"),imageflow.MozJPEG{})
	}).ConstrainWithin(400,400)
	.Encode(imageflow.GetBuffer("test"),imageflow.MozJPEG{})
	.Execute()
	ioutil.WriteFile("test_2.jpeg",data["test"],0644)
}

Documentation

Overview

Package imageflow is a fast image processing library

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type Black 

type Black struct{}

Black is the Implementation of interface Color and used as color black

type Buffer 

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

Buffer is io operation related to []byte

func GetBuffer 

func GetBuffer(key string) *Buffer

GetBuffer is used to get key

func NewBuffer 

func NewBuffer(buffer []byte) *Buffer

NewBuffer create a buffer operation

type Color 

type Color interface {
	// contains filtered or unexported methods
}

Color must be implemented by all the Colors that can be used by imageflow

type Constrain 

type Constrain struct {
	Mode        string         `json:"mode"`
	W           float64        `json:"w"`
	H           float64        `json:"h"`
	Hint        ConstraintHint `json:"hints"`
	Gravity     interface{}    `json:"gravity"`
	CanvasColor interface{}    `json:"canvas_color"`
}

Constrain is used to specify constraints for the image W The width constraint in pixels H The height constraint in pixels Mode A constraint mode Gravity determines how the image is anchored when cropped or padded. {x: 0, y: 0} represents top-left, {x: 50, y: 50} represents center, {x:100, y:100} represents bottom-right. Default: center Hints See resampling hints Canvas_color See Color. The color of padding added to the image.

type ConstraintGravity 

type ConstraintGravity struct {
	X float64 `json:"x"`
	Y float64 `json:"y"`
}

ConstraintGravity anchors the image

type ConstraintHint 

type ConstraintHint struct {
	SharpenPercent    interface{} `json:"sharpen_percent"`
	DownFilter        interface{} `json:"down_filter"`
	UpFilter          interface{} `json:"up_filter"`
	ScalingColorspace interface{} `json:"scaling_colorspace"`
	BackgroundColor   interface{} `json:"background_color"`
	ResampleWhen      interface{} `json:"resample_when"`
	SharpenWhen       interface{} `json:"sharpen_when"`
}

ConstraintHint is used to provided changes when resampling SharpenPercent (0..100) The amount of sharpening to apply during resampling UpFilter The resampling filter to use if upscaling in one or more directions DownFilter The resampling filter to use if downscaling in both directions. ScalingColorspace Use linear for the best results, or srgb to mimick poorly-written software. srgb can destroy image highlights. BackgroundColor The background color to apply. ResampleWhen One of size_differs, size_differs_or_sharpening_requested, or always. SharpenWhen One of downscaling, upscaling, size_differs, or always Supported Filters robidoux_sharp - A sharper version of the above robidoux_fast - A faster, less accurate version of robidoux ginseng - The default and suggested upsampling filter ginseng_sharp lanczos lanczos_sharp lanczos_2 lanczos_2_sharp cubic cubic_sharp catmull_rom mitchell cubic_b_spline hermite jinc triangle linear box fastest n_cubic n_cubic_sharp

type DrawExact 

type DrawExact struct {
	W     float32     `json:"w"`
	H     float32     `json:"h"`
	X     float32     `json:"x"`
	Y     float32     `json:"y"`
	Blend string      `json:"blend"`
	Hints interface{} `json:"hints"`
}

DrawExact is used to copy a part of image

type ExpandCanvas 

type ExpandCanvas struct {
	Left   float64     `json:"left"`
	Right  float64     `json:"right"`
	Top    float64     `json:"top"`
	Bottom float64     `json:"bottom"`
	Color  interface{} `json:"color"`
}

ExpandCanvas is used to expand the image

type File 

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

File is io operation related to file

func NewFile 

func NewFile(filename string) *File

NewFile is used to create a file io

type FitBox 

type FitBox interface {
	// contains filtered or unexported methods
}

FitBox is used to specify image position

type GIF 

type GIF struct{}

GIF is used to encode to gif

type LosslessPNG 

type LosslessPNG struct {
	MaxDeflate bool `json:"max_deflate"`
}

LosslessPNG is a encoder for lodepng

type LossyPNG 

type LossyPNG struct {
	Quality        int  `json:"quality"`
	MinimumQuality int  `json:"minimum_quality"`
	Speed          int  `json:"speed"`
	MaximumDeflate bool `json:"maximum_deflate"`
}

LossyPNG is used for encoding pngquant

type MarginFitBox 

type MarginFitBox struct {
	Left   float64 `json:"left"`
	Right  float64 `json:"right"`
	Top    float64 `json:"top"`
	Bottom float64 `json:"bottom"`
}

MarginFitBox is used to specify image position

type MozJPEG 

type MozJPEG struct {
	Quality     uint `json:"quality"`
	Progressive bool `json:"progressive"`
}

MozJPEG is used to encode using mozjpeg library

type PercentageFitBox 

type PercentageFitBox struct {
	X1 float64 `json:"x1"`
	Y1 float64 `json:"y1"`
	X2 float64 `json:"x2"`
	Y2 float64 `json:"y2"`
}

PercentageFitBox is used to specify image position

type RectangleToCanvas 

type RectangleToCanvas struct {
	FromX float32 `json:"from_x"`
	FromY float32 `json:"from_y"`
	W     float32 `json:"w"`
	H     float32 `json:"h"`
	X     float32 `json:"x"`
	Y     float32 `json:"y"`
}

RectangleToCanvas is used to copy a part of image

type Region 

type Region struct {
	X1              float64     `json:"x1"`
	Y1              float64     `json:"y1"`
	X2              float64     `json:"x2"`
	Y2              float64     `json:"y2"`
	BackgroundColor interface{} `json:"background_color"`
}

Region is like a crop command, but you can specify coordinates outside of the image and thereby add padding. It's like a window.

type RegionPercentage 

type RegionPercentage struct {
	X1              float64     `json:"x1"`
	Y1              float64     `json:"y1"`
	X2              float64     `json:"x2"`
	Y2              float64     `json:"y2"`
	BackgroundColor interface{} `json:"background_color"`
}

RegionPercentage is like a crop command, but you can specify coordinates outside of the image and thereby add padding. It's like a window.

type Steps 

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

Steps is the builder for creating a operation

func NewStep 

func NewStep() Steps

NewStep creates a step that can be used to specify how graph should be processed

func (*Steps) Alpha 

func (steps *Steps) Alpha(value float32) *Steps

Alpha histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) Branch 

func (steps *Steps) Branch(f func(*Steps)) *Steps

Branch create a alternate path for the output

func (*Steps) Brightness 

func (steps *Steps) Brightness(value float32) *Steps

Brightness histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) Command 

func (steps *Steps) Command(cmd string) *Steps

Command is used to execute query like strings

func (*Steps) Constrain 

func (steps *Steps) Constrain(dataMap Constrain) *Steps

Constrain is used to constraint a image

func (*Steps) ConstrainWithin 

func (steps *Steps) ConstrainWithin(w float64, h float64) *Steps

ConstrainWithin is used to constraint a image

func (*Steps) ConstrainWithinH 

func (steps *Steps) ConstrainWithinH(h float64) *Steps

ConstrainWithinH is used to constraint a image

func (*Steps) ConstrainWithinW 

func (steps *Steps) ConstrainWithinW(w float64) *Steps

ConstrainWithinW is used to constraint a image

func (*Steps) Contrast 

func (steps *Steps) Contrast(value float32) *Steps

Contrast histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) CopyRectangle 

func (steps *Steps) CopyRectangle(f func(steps *Steps), rect RectangleToCanvas) *Steps

CopyRectangle copy a image

func (*Steps) CropWhitespace 

func (steps *Steps) CropWhitespace(threshold int, padding float64) *Steps

CropWhitespace is used to remove whitespace around the image

func (*Steps) Decode 

func (steps *Steps) Decode(task ioOperation) *Steps

Decode is used to import a image

func (*Steps) DrawExact 

func (steps *Steps) DrawExact(f func(steps *Steps), rect DrawExact) *Steps

DrawExact copy a image

func (*Steps) Encode 

func (steps *Steps) Encode(task ioOperation, preset presetInterface) *Steps

Encode is used to convert the image

func (*Steps) Execute 

func (steps *Steps) Execute() (map[string][]byte, error)

Execute the graph

func (*Steps) ExpandCanvas 

func (steps *Steps) ExpandCanvas(canvas ExpandCanvas) *Steps

ExpandCanvas is used create a rectangle on the image

func (*Steps) FillRect 

func (steps *Steps) FillRect(x1 float64, y1 float64, x2 float64, y2 float64, color Color) *Steps

FillRect is used create a rectangle on the image

func (*Steps) FlipH 

func (steps *Steps) FlipH() *Steps

FlipH is to used to flip image horizontally

func (*Steps) FlipV 

func (steps *Steps) FlipV() *Steps

FlipV is to used to flip image horizontally

func (*Steps) GIF 

func (steps *Steps) GIF(operation ioOperation) *Steps

GIF encodes to a gif

func (*Steps) GrayscaleBT709 

func (steps *Steps) GrayscaleBT709() *Steps

GrayscaleBT709 histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) GrayscaleFlat 

func (steps *Steps) GrayscaleFlat() *Steps

GrayscaleFlat histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) GrayscaleNTSC 

func (steps *Steps) GrayscaleNTSC() *Steps

GrayscaleNTSC histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) GrayscaleRY 

func (steps *Steps) GrayscaleRY() *Steps

GrayscaleRY histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) Invert 

func (steps *Steps) Invert() *Steps

Invert histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) JPEG 

func (steps *Steps) JPEG(operation ioOperation) *Steps

JPEG encodes to a jpeg

func (*Steps) PNG 

func (steps *Steps) PNG(operation ioOperation) *Steps

PNG encodes to a png

func (*Steps) Region 

func (steps *Steps) Region(region Region) *Steps

Region is used to crop or add padding to image

func (*Steps) RegionPercentage 

func (steps *Steps) RegionPercentage(region RegionPercentage) *Steps

RegionPercentage is used to crop or add padding to image using percentage

func (*Steps) Rotate180 

func (steps *Steps) Rotate180() *Steps

Rotate180 is to used to rotate by 180 degrees

func (*Steps) Rotate270 

func (steps *Steps) Rotate270() *Steps

Rotate270 is to used to rotate by 270 degrees

func (*Steps) Rotate90 

func (steps *Steps) Rotate90() *Steps

Rotate90 is to used to rotate by 90 degrees

func (*Steps) Saturation 

func (steps *Steps) Saturation(value float32) *Steps

Saturation histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) Sepia 

func (steps *Steps) Sepia() *Steps

Sepia histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

func (*Steps) ToJSON 

func (steps *Steps) ToJSON() []byte

func (*Steps) Watermark 

func (steps *Steps) Watermark(data ioOperation, gravity interface{}, fitMode string, fitBox FitBox, opacity float32, hint interface{}) *Steps

Watermark is used to watermark a image

func (*Steps) WebP 

func (steps *Steps) WebP(operation ioOperation) *Steps

WebP encodes to a webp

func (*Steps) WhiteBalanceSRGB 

func (steps *Steps) WhiteBalanceSRGB(threshold float32) *Steps

WhiteBalanceSRGB histogram area This command is not recommended as it operates in the sRGB space and does not produce perfect results.

type Transparent 

type Transparent string

Transparent is the Implementation of interface Color and used as color transparent

type URL 

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

URL is used to make a http request to get file and use it

func NewURL 

func NewURL(url string) *URL

NewURL is used to create a new url operation

type WebP 

type WebP struct {
	Quality int `json:"quality"`
}

WebP is used to encode image using webp encoder

type WebPLossless 

type WebPLossless struct{}

WebPLossless is used to encode using webplossless encoder

Source Files

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