Introduction

The VAAL library and GStreamer plugins support input cropping as part of loading an image into a tensor managed by DeepViewRT.  This article describes the functionality.

GStreamer

The GStreamer plugins for DeepViewRT and ModelRunner both support crop properties, they are defined as left,right,top,bottom plus the "crop" property which combines all four into a single property.  The crop short-hand simply splits the provided string using the "," character then sets left,right,top,bottom accordingly.

The left,right,top,bottom properties give the position of the crop relative to the top-left of the input image, as pictured in the following diagram.

DeepViewRT

The properties are also documented by the plugin and can be reviewed using the "gst-inspect-1.0 deepviewrt" command, this will provide lots of details on the plugin including the crop properties.

  right               : Pixels to crop at the right of the input image
                        flags: readable, writable
                        Unsigned Integer. Range: 0 - 65535 Default: 0
  top                 : Pixels to crop at the top of the input image
                        flags: readable, writable
                        Unsigned Integer. Range: 0 - 65535 Default: 0

Requirements

The crop support as documented in this article was added in VAAL 1.0.6.