Get the blob stream of a media item using Sitecore PowerShell Extensions.

FindExifRotation.ps1

$exifOrientationId = 0x112

if(!$items) {
    $items = Get-ChildItem -Path "master:" -ID "{5D50B0FD-AB2B-4872-88E5-463D6E2B31F2}" -Recurse | Where-Object { $_.TemplateId -eq "{DAF085E8-602E-43A6-8299-038FF171349F}" }
}
$records = [System.Collections.ArrayList]@()
$processedCounter = 0
$totalCounter = $items.Count
foreach($item in $items) {
    $processedCounter++
    Write-Progress -Activity "Processing" -Status $item.Name -PercentComplete ($processedCounter * 100 / $totalCounter)
    $mediaItem = [Sitecore.Data.Items.MediaItem]$item
    $blobField = $mediaItem.InnerItem.Fields["blob"]
    $blobStream = $blobField.GetBlobStream()
    $image = [System.Drawing.Image]::FromStream($blobStream)
    if($image.PropertyIdList.Contains($exifOrientationId)) {
        $prop = $image.GetPropertyItem($exifOrientationId)
        $rot = [System.BitConverter]::ToUInt16($prop.Value, 0)
        if($rot -ne 0) {
            $record = [PSCustomObject]@{
                "ID" = $item.ID
                "ItemPath" = $item.ItemPath
                "RotateFlipType" = [Enum]::Parse([System.Drawing.RotateFlipType], $rot)
            }
            $records.Add($record) > $null
        }
    }
    
    $image.Dispose()
    $blobStream.Dispose()
}

$records | Show-ListView -Property ID,ItemPath,RotateFlipType

Get-MediaBlob.ps1

$item = Get-Item -Path "master:" -Id "{6AA5AA9F-071A-4808-91AC-709FAAFFB310}"
$mediaItem = [Sitecore.Data.Items.MediaItem]$item
$blobField = $mediaItem.InnerItem.Fields["blob"]
$blobField.GetBlobStream()