how to set admin image uploader from desktop?

dear all developer,

current OC image manager was showing the image from the server.
admin > image upload > direct browse from computer not server > select picture from computer > upload to server.
i believe this code can be done
just like simple php code but i was php "0" minded. i need help from this.
i do not want to show the image manager from the admin because it was show all server image file. i just want upload the picture from computer directly and without showing the image manager.
it was simply like php form which can upload file directly and also for image. just know how to adding the code into filemanager file.

does any expert out there. need help appreciate