Image resizing feature?

Question

PowerShell

Hello.
There is a task to resize an image in .jpg
format

Function Resize-Image
{   
     param(
         [String]$InputFile, 
         [String]$OutputFile, 
         [int]$Width, 
         [int]$Height
     )
     [reflection.assembly]::LoadWithPartialName("System.Drawing")
     $OriginImage = [System.Drawing.Bitmap]::FromFile($InputFile)
     $ResizedImage = New-Object System.Drawing.Bitmap @($Width, $Height)
     $graphics = [System.Drawing.Graphics]::FromImage($ResizedImage)
     $graphics.DrawImage($OriginImage, 0, 0, $Width, $Height)
     $graphics.Dispose()
     $ResizedImage.Save($OutputFile)
}

But it only changes the resolution (from larger to smaller), changing the file size up.
Is there a DrawImage method with a Scale or other parameter that allows you to change the file size down?

Answer 1

Recently I wrote for myself, it’s true that it also sprinkles into a square, but this can be removed, of course, by adding mathematics to calculate the new size.

function Resize-Image {
  <#
    .SYNOPSIS
        Resize-Image resizes an image file

    .DESCRIPTION
    This function uses the native .NET API to resize an image file

    .EXAMPLE
    Resize the image to a specific size:
        Resize-Image -InputFile "C:\userpic.jpg" -OutputFile "C:\userpic-400.jpg"-SquareHeight 400
    #>
  Param(
    [Parameter( Mandatory )]
    [string]$InputFile,
    [Parameter( Mandatory )]
    [string]$OutputFile,
    [Parameter( Mandatory )]
    [int32]$SquareHeight,
    [ValidateRange( 1, 100 )]
    [int]$Quality = 85
  )

  # Add System.Drawing assembly
  Add-Type -AssemblyName System.Drawing

  # Open image file
  $Image = [System.Drawing.Image]::FromFile( $InputFile )

  # Create empty square canvas for the new image
  # Calculate the offset for centering the image
  $Offset = 0
  $SquareSide = if ( $Image.Height -lt $Image.Width ) {
    $Image.Height
  } else {
    $Image.Width
    $Offset = ( $Image.Height - $Image.Width ) / 4
  }
  $SquareImage = New-Object System.Drawing.Bitmap( $SquareSide, $SquareSide )
  $SquareImage.SetResolution( $Image.HorizontalResolution, $Image.VerticalResolution )

  # Draw new image on the empty canvas
  $Canvas = [System.Drawing.Graphics]::FromImage( $SquareImage )
  $Canvas.DrawImage( $Image, 0, - $Offset )

  # Resize image
  $ResultImage = New-Object System.Drawing.Bitmap( $SquareHeight, $SquareHeight )
  $Canvas = [System.Drawing.Graphics]::FromImage( $ResultImage )
  $Canvas.DrawImage( $SquareImage, 0, 0, $SquareHeight, $SquareHeight )

  $ImageCodecInfo = [System.Drawing.Imaging.ImageCodecInfo]::GetImageEncoders() |
    Where-Object MimeType -eq 'image/jpeg'

  # https://msdn.microsoft.com/ru-ru/library/hwkztaft(v=vs.110).aspx
  $EncoderQuality = [System.Drawing.Imaging.Encoder]::Quality
  $EncoderParameters = New-Object System.Drawing.Imaging.EncoderParameters( 1 )
  $EncoderParameters.Param[0] = New-Object System.Drawing.Imaging.EncoderParameter( $EncoderQuality, $Quality )

  # Save the image
  $ResultImage.Save( $OutputFile, $ImageCodecInfo, $EncoderParameters )
}