goimagemerge

README

gim - Grid Based Image Merge Library

gim is a image merging library that can accept image paths as input, read the image contents, add background color, draw layers on top of each other, merge them into a grid with the desired size.

Table of Contents

• Overview
• Installation
• Getting Started
• Examples
  • Grid Unit Count - Vertical & Horizontal
  • Grid Background Color
  • Grid Layers - Draw Grids on top of Grids
• Functional Options
• TODO

Overview

gim provides an easy and extensible way to merge images into a flexible grid system.

The main purpose of the library is to help creating image collages programmatically.

Installation

go get -u github.com/ozankasikci/go-image-merge

Getting Started

Import the library and give the image paths and grid size as the minimum required arguments.

Basic usage:

import gim "github.com/ozankasikci/go-image-merge"

// accepts *Grid instances, grid unit count x, grid unit count y
// returns an *image.RGBA object
grids := []*gim.Grid{
	{ImageFilePath: "file.jpg"},
	{ImageFilePath: "file.png"},
}
rgba, err := gim.New(grids, 2, 1).Merge()

// save the output to jpg or png
file, err := os.Create("file/path.jpg|png")
err = jpeg.Encode(file, rgba, &jpeg.Options{Quality: 80})
err = png.Encode(file, rgba)

See Examples for available options and advanced usage.

Examples

Grid Unit Count - Vertical & Horizontal

grids := []*gim.Grid{
    {ImageFilePath: "./cmd/gim/input/kitten.jpg"},
    {ImageFilePath: "./cmd/gim/input/kitten.jpg"},
    {ImageFilePath: "./cmd/gim/input/kitten.jpg"},
    {ImageFilePath: "./cmd/gim/input/kitten.jpg"},
}
rgba, err := gim.New(grids, 2, 2).Merge()

Output

Grid Background Color

grids := []*gim.Grid{
    {
        ImageFilePath: "./cmd/gim/input/ginger.png",
        BackgroundColor: color.White,
    },
    {
        ImageFilePath: "./cmd/gim/input/ginger.png",
        BackgroundColor: color.RGBA{R: 0x8b, G: 0xd0, B: 0xc6},
    },
}
rgba, err := gim.New(grids, 2, 1).Merge()

Output

Grid Layers - Draw Grids on top of Grids

grids := []*gim.Grid{
    {
        ImageFilePath: "./cmd/gim/input/ginger.png",
        BackgroundColor: color.White,
        // these grids will be drawn on top of the first grid
        Grids: []*gim.Grid{
            {
            	ImageFilePath: "./cmd/gim/input/tick.png",
            	OffsetX: 50, OffsetY: 20,
            },
        },
    },
    {
        ImageFilePath: "./cmd/gim/input/ginger.png",
        BackgroundColor: color.RGBA{R: 0x8b, G: 0xd0, B: 0xc6},
        // these grids will be drawn on top of the second grid
        Grids: []*gim.Grid{
            {
            	ImageFilePath: "./cmd/gim/input/tick.png",
            	OffsetX: 200, OffsetY: 170,
            },
            {
            	ImageFilePath: "./cmd/gim/input/tick.png",
            	OffsetX: 200, OffsetY: 20,
            },
        },
    },
}
rgba, err := gim.New(grids, 2, 1).Merge()

Output

Functional Options

OptBaseDir

// you can omit the full path if you set a base dir
grids := []*gim.Grid{
    {ImageFilePath: "kitten.jpg"},
    {ImageFilePath: "kitten.jpg"},
}
rgba, err := gim.New(grids, 1, 2,
	gim.OptBaseDir("./cmd/gim/input"),
).Merge()

OptGridSize

// you can resize the grids in pixels
grids := []*gim.Grid{
    {ImageFilePath: "kitten.jpg"},
    {ImageFilePath: "kitten.jpg"},
}
rgba, err := gim.New( grids, 2, 1,
	gim.OptBaseDir("./cmd/gim"),
	gim.OptGridSize(200,150),
).Merge()

Output

TODO

• Add colored background support
• Add resize support (stretch, fit etc.)

Documentation

Index

• func OptBaseDir(dir string) func(*MergeImage)
• func OptGridSize(sizeX, sizeY int) func(*MergeImage)
• func OptGridSizeFromNthImageSize(n int) func(*MergeImage)
• type Grid
• type MergeImage
  • func New(grids []*Grid, imageCountDX, imageCountDY int, opts ...func(*MergeImage)) *MergeImage
  • func (m *MergeImage) Merge() (*image.RGBA, error)
  • func (m *MergeImage) ReadImageFile(path string) (image.Image, error)

Functions

func OptBaseDir

func OptBaseDir(dir string) func(*MergeImage)

OptBaseDir is an functional option to set the BaseDir field

func OptGridSize

func OptGridSize(sizeX, sizeY int) func(*MergeImage)

OptGridSize is an functional option to set the GridSize X & Y

func OptGridSizeFromNthImageSize

func OptGridSizeFromNthImageSize(n int) func(*MergeImage)

OptGridSizeFromNthImageSize is an functional option to set the GridSize from the nth image

Types

type Grid

type Grid struct {
	Image           *image.Image
	ImageFilePath   string
	BackgroundColor color.Color
	OffsetX         int
	OffsetY         int
	Grids           []*Grid
}

Grid holds the data for each grid

type MergeImage

type MergeImage struct {
	Grids           []*Grid
	ImageCountDX    int
	ImageCountDY    int
	BaseDir         string
	FixedGridSizeX  int
	FixedGridSizeY  int
	GridSizeMode    gridSizeMode
	GridSizeFromNth int
}

MergeImage is the struct that is responsible for merging the given images

func New

func New(grids []*Grid, imageCountDX, imageCountDY int, opts ...func(*MergeImage)) *MergeImage

New returns a new *MergeImage instance

func (*MergeImage) Merge

func (m *MergeImage) Merge() (*image.RGBA, error)

Merge reads the contents of the given file paths, merges them according to given configuration

func (*MergeImage) ReadImageFile

func (m *MergeImage) ReadImageFile(path string) (image.Image, error)