Windows Powershell Script to download the latest image from the Himawari-8 satelite, combine the tiles into a single image, convert to jpg and then set as the desktop background.

himawari.ps1

#
# Himawari-8 Downloader
#
#
#
# This script will scrape the latest image from the Himawari-8 satellite, recombining the tiled image,
# converting it to a JPG which is saved in My Pictures\Himawari\ and then set as the desktop background.
#
# http://himawari8.nict.go.jp/himawari8-image.htm
#
#

param(
    [Switch] $Force,
    [Switch] $StoreLatestOnly
)

Write-Output "Checking for latest"

$latest_result = $null
        
try {
    $cachebuster = [DateTime]::UtcNow.ToFileTime()
    $response = Invoke-WebRequest "http://himawari8-dl.nict.go.jp/himawari8/img/D531106/latest.json?uid=$cachebuster"
    $latest_result = $response.Content | ConvertFrom-Json
}
catch {
    Write-Error "Failed to retrieve latest ($x, $y): $($_.Exception.Message)"
    return
}

if (!$latest_result -or !$latest_result.date) {
    Write-Error 'Unable to retrieve latest date'
    return
}

$latest_date = (Get-Date $latest_result.Date)

$width = 550
$level = 4 #Level can be 4, 8, 16, 20
$time = $latest_date.ToString("HHmmss")
$year = $latest_date.ToString("yyyy")
$month = $latest_date.ToString("MM")
$day = $latest_date.ToString("dd")

#Create the folder My Pictures\Himawari\ if it doesnt exist
$outpath = (Join-Path ([Environment]::GetFolderPath("MyPictures")) "Himawari")
if(!(Test-Path $outpath))
{
    [void](New-Item -ItemType directory -Path $outpath)
}

# The filename that will be saved

if ($StoreLatestOnly.IsPresent) {
    # Use this to have the script just store the latest file only
    $outfile = Join-Path $outpath "latest.jpg"
}
else {
    # Use this to have the files accumulate in the directory:
    $outfile = Join-Path $outpath "$($year)$($month)$($day)_$($time).jpg"
}

# Have we already downloaded this one?
# Override this check when $StoreLatestOnly or $Force was provided
if (!$StoreLatestOnly.IsPresent -and (!$Force.IsPresent -and (Test-Path $outfile))) {
    Write-Warning "$outfile already exists! Use -Force to redownload."
    return
}

[void][Reflection.Assembly]::LoadWithPartialName("System.Drawing")

$image = New-Object System.Drawing.Bitmap(($width * $level), ($width * $level))
try {
    
    # Settings for saving images as JPEG
    $qualityEncoder = [System.Drawing.Imaging.Encoder]::Quality
    $encoderParams = New-Object System.Drawing.Imaging.EncoderParameters(1)
    $encoderParams.Param[0] = New-Object System.Drawing.Imaging.EncoderParameter($qualityEncoder, 90)
    $jpegCodecInfo = [System.Drawing.Imaging.ImageCodecInfo]::GetImageEncoders() | where MimeType -eq 'image/jpeg'
    
    # Drawing context
    $graphics = [System.Drawing.Graphics]::FromImage($image)
    $graphics.Clear([System.Drawing.Color]::Black)

    for ($y = 0; $y -lt $level; $y++)
    {
        for ($x = 0; $x -lt $level; $x++)
        {
            $block_url = "http://himawari8-dl.nict.go.jp/himawari8/img/D531106/$($level)d/$width/$year/$month/$day/$($time)_$($x)_$($y).png"
            Write-Output "Downloading chunk: $block_url"

            try
            {
                $response = Invoke-WebRequest $block_url
                if ($response.Headers.'Content-Type' -ne 'image/png') {
                    Write-Error 'Received non-PNG response to chunk query'
                    return
                }
                
                $imgblock = [System.Drawing.Image]::FromStream((new-object System.IO.MemoryStream((, [byte[]] $response.Content))))
                #$imgblock.Save((Join-Path $outpath "image_$($x)_$($y).png"), $jpegCodecInfo, $encoderParams)
                try {
                    $graphics.DrawImage($imgblock, ($x * $width), ($y * $width) , $width, $width)
                }
                finally {   
                    $imgblock.Dispose()
                }
            }
            catch {
                Write-Error "Failed to download chunk ($x, $y): $($_.Exception.Message)"
                return
            }
        }
    }
    
    Write-Output "Writing to $outfile..."
    $image.save($outfile, $jpegCodecInfo, $encoderParams)
}
finally {
    $image.Dispose()
}

<#
 Different settings for the wallpaper:

    Tile :
        key.SetValue(@"WallpaperStyle", "0") ; 
        key.SetValue(@"TileWallpaper", "1") ; 
        break;
    Center :
        key.SetValue(@"WallpaperStyle", "0") ; 
        key.SetValue(@"TileWallpaper", "0") ; 
        break;
    Stretch :
        key.SetValue(@"WallpaperStyle", "2") ; 
        key.SetValue(@"TileWallpaper", "0") ;
        break;
    Fill :
        key.SetValue(@"WallpaperStyle", "10") ; 
        key.SetValue(@"TileWallpaper", "0") ; 
        break;
    Fit :
        key.SetValue(@"WallpaperStyle", "6") ; 
        key.SetValue(@"TileWallpaper", "0") ; 
        break;
#>


Write-Output "Setting Wallpaper..."
Set-ItemProperty -path "HKCU:Control Panel\Desktop" -name Wallpaper -value $outfile
Set-ItemProperty -path "HKCU:Control Panel\Desktop" -name WallpaperStyle -value 6
Set-ItemProperty -path "HKCU:Control Panel\Desktop" -name TileWallpaper -value 0
Set-ItemProperty 'HKCU:\Control Panel\Colors' -name Background -Value "0 0 0"
#rundll32.exe user32.dll, UpdatePerUserSystemParameters


$source = @"
using System.Runtime.InteropServices;
public class Wallpaper
{
    public const int SetDesktopWallpaper = 20;
    public const int UpdateIniFile = 0x01;
    public const int SendWinIniChange = 0x02;
    
    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    private static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);
    
    public static void SetWallpaper(string path)
    {
        SystemParametersInfo(SetDesktopWallpaper, 0, path, UpdateIniFile | SendWinIniChange);
    }
}
"@
Add-Type -TypeDefinition $source
[Wallpaper]::SetWallpaper($outfile)


Write-Output "Done"