get_roi_canvas_from_instance

Get a Region of Interest (ROI) using an instance

diffgram.get_roi_canvas_from_instance

Arguments

instance : a Diffgram instance
canvas : a canvas type element

Description

The goal of this is to return a new canvas element ready to be consumed by functions that want to focus on a specific area of the image. For example grabcut or similar, or running an algorithm on a subsection of a large image or frame.

Example

let canvas = diffgram.get_new_canvas()
let roi_canvas = diffgram.get_roi_canvas_from_instance(
    instance,
    canvas
)

Example (Using Watcher)

// Click Watch Then draw an instance and look at dev tools
create_instance: function (data){

  let canvas = diffgram.get_new_canvas()
  let instance = {...data[0]}

  let roi_canvas = diffgram.get_roi_canvas_from_instance(
    instance,
    canvas
    ) 
  console.log(roi_canvas)
 }

Drawing an instance example

18571857

Returns

A canvas cropped to the region desired