Image Converter

Package imgconv provides basic image processing functions (resize, add watermark, format converter.).

All the image processing functions provided by the package accept any image type that implements image.Image interface as an input, include jpg(jpeg), png, gif, tif(tiff), bmp, webp(decode only) and pdf.

Installation

go get -u github.com/sunshineplan/imgconv

License

The MIT License (MIT)

Credits

This repo relies on the following third-party projects:

• disintegration/imaging
• pdfcpu/pdfcpu
• hhrutter/tiff

Usage examples

A few usage examples can be found below. See the documentation for the full list of supported functions.

Image resizing

// Resize srcImage to size = 128x128px.
dstImage128 := imgconv.Resize(srcImage, &imgconv.ResizeOption{Width: 128, Height: 128})

// Resize srcImage to width = 800px preserving the aspect ratio.
dstImage800 := imgconv.Resize(srcImage, &imgconv.ResizeOption{Width: 800})

// Resize srcImage to 50% size preserving the aspect ratio.
dstImagePercent50 := imgconv.Resize(srcImage, &imgconv.ResizeOption{Percent: 50})

Image splitting

// Split srcImage into 3 parts horizontally.
imgs, err := imgconv.Split(srcImage, 3, imgconv.SplitHorizontalMode)

// Split srcImage into 3 parts vertically.
imgs, err := imgconv.Split(srcImage, 3, imgconv.SplitVerticalMode)

Add watermark

// srcImage add a watermark at randomly position.
dstImage := imgconv.Watermark(srcImage, &WatermarkOption{Mark: markImage, Opacity: 128, Random: true})

// srcImage add a watermark at fixed position with offset.
dstImage := imgconv.Watermark(srcImage, &WatermarkOption{Mark: markImage, Opacity: 128, Offset: image.Pt(5, 5)})

Format convert

// Convert srcImage to dst with jpg format.
imgconv.Write(dstWriter, srcImage, &imgconv.FormatOption{Format: imgconv.JPEG})

Example code

package main

import (
	"io"
	"log"

	"github.com/sunshineplan/imgconv"
)

func main() {
	// Open a test image.
	src, err := imgconv.Open("testdata/video-001.png")
	if err != nil {
		log.Fatalf("failed to open image: %v", err)
	}

	// Resize the image to width = 200px preserving the aspect ratio.
	mark := imgconv.Resize(src, &imgconv.ResizeOption{Width: 200})

	// Add random watermark set opacity = 128.
	dst := imgconv.Watermark(src, &imgconv.WatermarkOption{Mark: mark, Opacity: 128, Random: true})

	// Write the resulting image as TIFF.
	if err := imgconv.Write(io.Discard, dst, &imgconv.FormatOption{Format: imgconv.TIFF}); err != nil {
		log.Fatalf("failed to write image: %v", err)
	}

	// Split the image into 3 parts horizontally.
	imgs, err := imgconv.Split(src, 3, imgconv.SplitHorizontalMode)
	if err != nil {
		log.Fatalf("failed to split image: %v", err)
	}
}