ImgBB.com API Powershell Module
While hanging out in the PowerShell Discord #Powershell-help channel. Someone asked for help in uploading screenshots directly to the imgbb.com API. As always when digging into something, I had to fully dive into the issue.
As with many APIs I've worked with recently, there was little to no documentation, save a very basic example, as shown below.
curl --location --request POST "https://api.imgbb.com/1/upload?expiration=600&key=YOUR_CLIENT_API_KEY" --form "image=R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"
I had not worked with an API previously that required x-www-form-urlencoded parameters. Always keen to learn new methods, especially when interacting with an API, I spent a decent ammount of time learning how to upload images using this API.
The first step was to create an account on the website and get an API key to authenticate with. Doing so was an easy process with the basic sign up, confirm your email and click Generate API Key process.
Once I had an API key, the next step was converting the curl example into an Invoke-RestMethod invokation. As easy as this sounds, it's not always that easy to accomplish. Every API is slightly differnt in how it will accept arguments and input.
I started using the [URIBuilder] class, which is the basis for most of the project in which I interact with REST APIs. The class makes it easy to adjust paths, queries and http or https requests. I later found that the URI encoding of the path portion of the URL, didn't play nicely with the API, and was skewing the results. It caused the API to return an Invalid v1 API Key error. I then resorted to hard-coding the URI in the Invoke-RestMethod command.
I later discovered the version of Invoke-RestMethod included with PowerShell 7+ had an argument of -form. Further research showed the -ContentType Form argument was a customized version of a -Body statement. Since the -ContentType Form argument was availabe, I chose to write the module requiring 7.0 or better. The final Invoke-RestMethod call is shown below.
Invoke-RestMethod -Method POST -Uri ("https://api.imgbb.com/1/upload?key={0}" -f $Key) -Body $Form -ContentType form
The final obsticle was converting an image into Base64 format. This is a fairly easy task. Making use of the [convert]::ToBase64String() class and method. However before converting to Base64, we must first convert the image into a Byte array. We can make this very efficient by combining the two processes into [convert]::ToBase64String((get-content $path -AsByteStream)), where $path is the file passed by the function. The completed resulting function is shown below.
I chose to add a [switch]$OpenInBrowser optional switch to the function as a quality of life improvement to the function.
After reviewing the output of the API, I chose options I felt that would be most useful to those who may use the module. Those being, the full URL, shortened URL, thumbnail URL, medium URL and the URL which gives a delete option.
Function _UploadImage {
Param(
[String]$path,
[String]$key,
[Switch]$OpenInBrowser
)
$Form = @{
image = [convert]::ToBase64String((get-content $path -AsByteStream))
}
try {
$response = Invoke-RestMethod -Method POST -Uri ("https://api.imgbb.com/1/upload?key={0}" -f $Key) -Body $Form -ContentType form
}
catch {
$_.Exception.Response
}
$output = [PSCustomObject]@{
Image = $response.data.display_url
ShortURL = $response.data.url_viewer
DeleteURL = $response.data.delete_url
ThumbnailURL = $response.data.thumb.url
MediumURL = $response.data.medium.url
}
if ($OpenInBrowser) {
Start-Process $output.Image
}
return $output
}
Bulding on the success of this function, I assumed there would be those who may want to upload a whole folder of images. Not to leave those poor souls out in the cold, I created the _UploadFolder function.
This function takes pipeline input from Get-ChildItem and processes each item individually; returning a [PScustomObject] for each upload.
While all this worked very well, this did not satisfy the requirements of the person in Discord I was trying to help. They wanted to automatically upload screen shots directly to ImgBB.com. I first wrote out the _ScreenCapture_ function as shown below, which will send the PrintScreen button via the [Windows.Forms.SendKeys] class to trigger a Print Screen event. As Windows saves Print Screen data to the clipboard, the next step was to save the clipboard data to a variable using $BitMap = [Windows.Forms.Clipboard]::GetImage().
Now that we have the screen grap from Print Screen, we can start manipulating the data for upload.
The next step is to create a new memory stream instance using $Stream = [IO.MemoryStream]::new(). This will let us convert the Print Screen data into a memory stream using $bitmap.Save($Stream, [Drawing.Imaging.ImageFormat]::Jpeg).
Now that we finally have the data in a memory stream, we can convert into a Byte array, then finally into Base64 for upload. The final function is shown below. I chose to create a separate function _Uploadstream to process the upload portion of the process, which is shown below as well.
function _ScreenCapture{
param(
[String]$Key,
[Switch]$OfWindow
)
begin {
Add-Type -AssemblyName System.Drawing
}
process {
Start-Sleep -Milliseconds 250
if ($OfWindow) {
[Windows.Forms.Sendkeys]::SendWait("%{PrtSc}")
} else {
[Windows.Forms.Sendkeys]::SendWait("{PrtSc}")
}
Start-Sleep -Milliseconds 250
$bitmap = [Windows.Forms.Clipboard]::GetImage()
$Stream = [IO.MemoryStream]::new()
$bitmap.Save($Stream, [Drawing.Imaging.ImageFormat]::Jpeg)
[byte[]]$ImageByes = $Stream.ToArray()
_UploadStream -Image $ImageByes -Key $Key -OpenInBrowser
}
}
Function _UploadStream {
Param(
[byte[]]$Image,
[String]$key,
[Switch]$OpenInBrowser
)
$Form = @{
image = [convert]::ToBase64String($image)
}
try {
$response = Invoke-RestMethod -Method POST `
-Uri ("https://api.imgbb.com/1/upload?key={0}&Name={1}" -f $Key,$Env:COMPUTERNAME+"-"+(Get-Date -Format "MM-dd-yyyy-HH:mm")) -Body $Form
}
catch {
$_.Exception.Response
}
$output = [PSCustomObject]@{
Image = $response.data.display_url
ShortURL = $response.data.url_viewer
DeleteURL = $response.data.delete_url
ThumbnailURL = $response.data.thumb.url
MediumURL = $response.data.medium.url
}
if ($OpenInBrowser) {
Start-Process $output.Image
}
return $output
}