Block operations

operations

VDMS allows for operations to be performed to an image at insertion and/or query time. Currently supported operations are: threshold, crop, resize. Therefore, those are the operations currently recognized in this block. More operations can be added in the future.

At least one operation must be defined in the array.

All the parameters are required for each operation. The parameters for the various operations supported are:

Parameters

• type: Type of operation [crop, threshold, resize].

• others (dependent on the type):

  • threshold:

    • value: is the value of the threshold above which all pixel values are returned and below which all pixel values are zeroed

  • crop:

    • "x", "y": specify the starting position x and y.
    • "width", "height": specify the width and height of the crop.

  • resize:

    • "width", "height": give the new expected width and height of the image, performs bilinear interpolation entity (entities).

  • flip:

    • "code": Follows OpenCV convention: 0 for Vertical flip, >0 for Horizontal flip, <0 for both.

  • rotate:

    • "angle", "resize": Rotation angle, and the "resize" flag to specify whether the image will be resized so that the rotated image fits (resize = true), or if the image will be kept the same size (resize = false).

Example

// resize and threshold
"operations": [
    {
        "type": "resize",
        "width": 200, "height": 200,
    }
    {
        "type": "threshold",
        "value": 155,
    }
],


// Crop and threshold
"operations": [
    {
        "type": "crop",
        "x": 255, "y": 155,
        "width": 15, "height": 10,
    },
    {
        "type": "threshold",
        "value": 155,
    }
],

// Flip and rotate
"operations": [
    {
        "type": "flip",
        "code": 1 // Horizontal Flip
    },
    {
        "type": "rotate",
        "angle": 45,
        "resize": False
    }
],