Tools of CCTVCAD Lab Toolkit > Image analyzer > Size and contrast of an object

With this tab you can measure size of arbitrary object on the image and its contrast relatively to background.

Order of measuring:

1. Specify background

Place the cursor on the image, press left mouse button and move the cursor. Specify background region by selection window and release the mouse button.

On the Background panel the following data is displayed:

•	Size - background size in pixels and percents from the image size.

•	Area - background area in pixels and percents from the image area.

•	Avr. brightness - average brightness of the background.

•	Difference - difference of background brightness.

2. Specify an object

Click the switch Step 2. Specify an object.

Place the cursor on the image, press left mouse button and move the cursor. Specify the object by selection window and release mouse button.

On the Object region panel the following data will be displayed:

•	Size - object size in pixels and percents from the image size.

•	Area - object area in pixels and percents from the image area.

•	Avr. brightness - average brightness of the object.

3. Calculation

Click the Step 3.Calculation button.

In the Object-background contrast box the contrast between object and background is displayed.

The contract is calculated by the formula:

Contrast = Avarage Brightness of the object – Avarage background brightness.

When moving the cursor over the image on the tab bottom the following data is displayed:

•	Before specifying background – pixel brightness under the cursor.

•	After specifying background – pixel contrast under the cursor relatively to the background.