mirror of https://github.com/status-im/resize.git
90 lines
1.9 KiB
Markdown
90 lines
1.9 KiB
Markdown
Resize
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======
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Image resizing for the [Go programming language](http://golang.org) that includes a few interpolation methods.
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Installation
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------------
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```bash
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$ go get github.com/nfnt/resize
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```
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It's that easy!
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Usage
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-----
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Import package with
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```go
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import "github.com/nfnt/resize"
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```
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Resize creates a scaled image with new dimensions (`width`, `height`) using the interpolation function `interp`.
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If either `width` or `height` is set to 0, it will be set to an aspect ratio preserving value.
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```go
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resize.Resize(width, height uint, img image.Image, interp resize.InterpolationFunction) image.Image
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```
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The provided interpolation functions are
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- `NearestNeighbor`: [Nearest-neighbor interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation)
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- `Bilinear`: [Bilinear interpolation](http://en.wikipedia.org/wiki/Bilinear_interpolation)
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- `Bicubic`: [Bicubic interpolation](http://en.wikipedia.org/wiki/Bicubic_interpolation)
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- `Lanczos2`: [Lanczos resampling](http://en.wikipedia.org/wiki/Lanczos_resampling) with a=2
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- `Lanczos3`: [Lanczos resampling](http://en.wikipedia.org/wiki/Lanczos_resampling) with a=3
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Sample usage:
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```go
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package main
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import (
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"github.com/nfnt/resize"
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"image/jpeg"
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"log"
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"os"
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)
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func main() {
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// open "test.jpg"
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file, err := os.Open("test.jpg")
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if err != nil {
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log.Fatal(err)
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}
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// decode jpeg into image.Image
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img, err := jpeg.Decode(file)
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if err != nil {
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log.Fatal(err)
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}
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file.Close()
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// resize to width 1000 using Lanczos resampling
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// and preserve aspect ratio
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m := resize.Resize(1000, 0, img, resize.Lanczos3)
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out, err := os.Create("test_resized.jpg")
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if err != nil {
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log.Fatal(err)
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}
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defer out.Close()
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// write new image to file
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jpeg.Encode(out, m, nil)
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}
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```
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TODO
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----
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- Minimize calls to image.Image.At(): It's pretty slow but inevitable as it keeps the code generic
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License
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-------
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Copyright (c) 2012 Jan Schlicht <janschlicht@gmail.com>
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Resize is released under an MIT style license.
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