Save Image file on persist method - acumatica

Question

I have been trying to save image file that's been copied from screenshot and pasted into the PXImage control. Now, when I save the record I am trying to save the image as well and save the name of the file in database record along with other DAC fields.
Below is the js code that sets the screenshot image into the PXImage control.
document.onpaste = function (event) {
var items = (event.clipboardData || event.originalEvent.clipboardData).items;
console.log(JSON.stringify(items)); // will give you the mime types
if (items.length > 0) {
var imgControl = document.querySelectorAll('.note-m img');
//get the last screenshot
var item = items[items.length - 1];
if (item.kind === 'file') {
var blob = item.getAsFile();
var reader = new FileReader();
reader.onload = function (event) {
var result = event.target.result;
imgControl[0].src = result;
px_alls["ds"].executeCallback("saveScreenshotImage","test");
};
reader.readAsDataURL(blob);
}
}
}
This is how it looks when I press (Ctrl+V) on the screenshot.
Now, I want to save this image and generate a file name that I can save on DAC field called 'ScreenShotImage' along with the record.
I thought of creating an action and calling that via js but I couldn't succeed on passing image as a command argument.
Action method in graph:
public PXAction<Ticket> saveScreenshotImage;
[PXButton]
public virtual IEnumerable SaveScreenshotImage(PXAdapter adapter)
{
throw new PXException("test...");
}
Calling via JS
px_alls["ds"].executeCallback("saveScreenshotImage");
Is there any way, I can get that particular file on Persist method?
public override void Persist()
{
base.Persist();
}
Thank you.