Get hight quality image via himawari8 by @pepsin

himawari8.rb

require 'net/http' 
require "cairo" 

def get_url time, x, y 
    str = "http://himawari8-dl.nict.go.jp/himawari8/img/D531106/20d/550/#{time}00_#{x}_#{y}.png" 
end 

def merge time 
    puts "Start image process" 
    w = 20 
    h = 20 
    partial_width = 550 
    surface = Cairo::ImageSurface.new(w * partial_width, h * partial_width) 
    cr = Cairo::Context.new(surface) 

    arr = [] 
    h.times do |y| 
        w.times do |x| 
            name = "himawari_#{x}_#{y}.png" 
            arr.push name 
            puts name 
            png = Cairo::ImageSurface.from_png(name) 
            cr.set_source(*png) 
            cr.matrix = Cairo::Matrix.new(1,0,0,1,x * partial_width, y * partial_width) 
            cr.paint() 
        end 
    end 

    cr.target.write_to_png("#{time.split("/").join("_")}.png") 
    cr.destroy 
    surface.destroy 
    arr.each do |file| 
        File.delete file 
    end 
end 

def run time 
    merge_name = time.split("/").join("_") + ".png" 
    unless File.exists? merge_name 
        ts = [] 
        20.times do |x| 
            thread = Thread.new do 
                20.times do |y| 
                    name = "himawari_#{x}_#{y}.png" 
                    unless File.exists? name 
                        url = get_url time, x, y 
                        uri = URI.parse(url) 
                        req = Net::HTTP::Get.new uri.path 
                        res = Net::HTTP.start(uri.host, uri.port, use_ssl: false) do |http| 
                            http.request req 
                        end 

                        file = File.open(name, "w+") 
                        file.write(res.body) 
                        file.close 
                    end 
                end 
            end 
            ts.push thread 
        end 
        ts.map(&:join) 
        sleep 5 
    end 

    unless File.exists? merge_name 
        merge time 
    end 
end 

24.times do |hour| 
    hour = hour.to_s 
    if hour.length < 2 
        hour = "0" + hour 
    end 
    6.times do |minute| 
        minute = (minute * 10).to_s 
        if minute.length < 2 
            minute = "0" + minute 
        end 
        str = "2015/12/01/" + hour + minute 
        puts str 
        run str 
    end 
end 

# run "2015/12/01/0000"

• How to use ?

  • Install Ruby

    • apt (Debian 或 Ubuntu)

      sudo apt-get install ruby-full
      

    • yum (CentOS、Fedora 或 RHEL(

      sudo yum install ruby
      

    • Other Distributions

    See : Ruby installation

• Download & Use Script

  curl https://gist.githubusercontent.com/p0we7/5783db11ec2ddeb67d14/raw/himawari8.rb -o himawari8.rb
  ruby himawari8.rb