Contrast / Brightness

This layer (contrast_brightness) randomly changes contrast and brightness of images.

Settings

• contrast (type: object)

  • min (type: number, minimum: 0, maximum: 10)
  • max (type: number, minimum: 0, maximum: 10)
  • center_grey (type: boolean, default: false)

• brightness (type: object)

  • min (type: number, minimum: -255, maximum: 255)
  • max (type: number, minimum: -255, maximum: 255)

Image contrast is changed by multiplying each pixel by random value with uniform distribution from min to max. To disable, set min and max to 1. To center colors of images (subtract 128) first, set center_grey to true.

Image brightness is changed by adding to each pixel a random value with uniform distribution from min to max. To disable, set min and max to 0.

Preview

center_grey = false (Default):

center_grey = true:

Example

[
  {
    "dst": "$data",
    "src": [
      "example/*"
    ],
    "action": "data",
    "settings": {
      "classes_mapping": "default"
    }
  },
  {
    "action": "multiply",
    "src": ["$data"],
    "dst": "$data2",
    "settings": {
      "multiply": 5
    }
  },
  {
    "dst": "$result",
    "src": [
      "$data2"
    ],
    "action": "contrast_brightness",
    "settings": {
      "contrast": {
        "min": 0.5,
        "max": 2,
        "center_grey": false
      },
      "brightness": {
        "min": -50,
        "max": 50
      }
    }
  },
  {
    "dst": "example_b_c",
    "src": [
      "$result"
    ],
    "action": "supervisely",
    "settings": {}
  }
]