windows 7 x64 - Scan automation with PowerShell and WIA - How to set PNG as image type -

what have: i'm using powershell 2.0 , wia scan , save image flatbed scanner. goal avoid dialogs, single click. code simple, short , works.

$devicemanager = new-object -comobject wia.devicemanager $device = $devicemanager.deviceinfos.item(1).connect()      foreach ($item in $device.items) {      $image = $item.transfer()  }      $image.savefile("d:\scan.$($image.fileextension)") 

problem: method above produces bmp files. wanted png files instead.

i saw c# code uses wia method user able pass arguments scan dialog png file format

now wonder if , how it's possible achieve same powershell

---

i found of code here

• http://deletethis.net/dave/?uri=http%3a%2f%2fcerealnumber.livejournal.com%2f47638.html
• http://ardalis.com/powershell-control-over-nikon-d3000-camera
• http://msdn.microsoft.com/en-us/library/windows/desktop/ms630806(v=vs.85).aspx

_{ps: in case solution involves 'take picture' command (wiacommandtakepicture). unfortunalty canoscan lide 210 doesn't support command}

you should pass formatid string argument transfer method. list of available formats available in msdn

however, there's catch. explained here, transfer method doesn't have observe requested format, , output must converted manually in case. converting msdn's vb example powershell (works on machine scanner):

$devicemanager = new-object -comobject wia.devicemanager $device = $devicemanager.deviceinfos.item(1).connect()      $wiaformatpng = "{b96b3caf-0728-11d3-9d7b-0000f81ef32e}" foreach ($item in $device.items) {      $image = $item.transfer($wiaformatpng)  }      if($image.formatid -ne $wiaformatpng) {     $imageprocess = new-object -comobject wia.imageprocess     $imageprocess.filters.add($imageprocess.filterinfos.item("convert").filterid)     $imageprocess.filters.item(1).properties.item("formatid").value = $wiaformatpng     $image = $imageprocess.apply($image) }  $image.savefile("c:/my_full_path/test.png")