wikimg

README

wikimg

Documentation

Overview

Package wikimg can pull the latest image URLs from Wikimedia Commons https://commons.wikimedia.org and map image colors to an xterm256 color palette.

Example

package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"

	"github.com/brnstz/routine/wikimg"
)

func main() {
	// Save 10 random images to a directory

	// Create a pull with max 10 results
	p := wikimg.NewPuller(10)

	// Create temp dir for storing the images
	dir, err := ioutil.TempDir("", "")
	if err != nil {
		panic(err)
	}

	// Remove dir after test is complete
	defer os.RemoveAll(dir)

	for {
		// Get the next URL
		imgURL, err := p.Next()

		if err == wikimg.EndOfResults {
			// We've reached the end
			break
		} else if err != nil {
			// There's an unexpected error
			panic(err)
		}

		// Call GET on the image URL
		resp, err := http.Get(imgURL)
		if err != nil {
			panic(err)
		}

		// Open a temporary file
		fh, err := ioutil.TempFile(dir, "")
		if err != nil {
			// We need to close our HTTP response here too
			resp.Body.Close()
			panic(err)
		}

		// Copy GET results to file and close stuff
		_, err = io.Copy(fh, resp.Body)
		fh.Close()
		resp.Body.Close()
		if err != nil {
			panic(err)
		}
	}

	files, _ := ioutil.ReadDir(dir)
	fmt.Println(len(files))

}

Output:

10

Index

• Variables
• type Puller
  • func NewPuller(max int) *Puller
  • func (p *Puller) FirstColor(imgURL string) (xtermColor int, hex string, err error)
  • func (p *Puller) Next() (string, error)

Examples

• Package

Variables

var (
	// EndOfResults is returned by Next() when no more results are available
	EndOfResults = errors.New("end of results")

	// Canceled may be returned by Next() and FirstColor() when the client
	// closes the Cancel channel on a Puller
	Canceled = errors.New("wikimg: canceled image processing")
)

var XTerm256 = []color.Color{}/* 256 elements not displayed */

XTerm256 is a 256 color palette where the index value is the xterm-256 color id. For example, 0 = #000000 (black) and 1 = #800000 (red) Source: http://www.calmar.ws/vim/256-xterm-24bit-rgb-color-chart.html

Types

type Puller

type Puller struct {

	// Cancel is an optional channel. Setting this value on Puller
	// and closing the channel signals to the Puller that any
	// in process operations (i.e, retrieving an image or computing
	// its first color) should be canceled. Any future
	// calls to Next() or FirstColor() will return a Canceled
	// error.
	Cancel <-chan struct{}
	// contains filtered or unexported fields
}

Puller is an image puller that retrieves the most recent image URLs that have been uploaded to Wikimedia Commons https://commons.wikimedia.org

func NewPuller

func NewPuller(max int) *Puller

NewPuller creates a puller that can return at most max images when calls to Next() are made

func (*Puller) FirstColor

func (p *Puller) FirstColor(imgURL string) (xtermColor int, hex string, err error)

FirstColor tries to return the first non-gray color in the image. A gray color is one that, when mapped to an xterm256 palette, has the same value for red, green and blue. We iterate through pixels starting with 0,0 and through each x and y value. In the worst case (a grayscale image), we iterate through every pixel, give up, and return the final pixel color even though it's gray. Both the xtermColor (an integer between 0-255) and a hex string (e.g., "#bb00cc") is returned.

func (*Puller) Next

func (p *Puller) Next() (string, error)

Next returns the next most recent image URL. If no more results are available EndOfResults is returned as an error.