Screen ruler utility

Screen ruler allows you to quickly measure pixels on your screen based on image edge detection. This was inspired by Pete Blois's Rooler.

How to activate

Press ⊞ Win+Shift+M to activate and then select which tool you want to measure with. To exit, press Esc or click ╳ in the toolbar.

How to use

• Bounds (Dashed square symbol): This is a bounding box. Click and drag with your mouse. If you hold Shift, the box(es) will stay in place until you cancel the interaction.
• Spacing (╋): This will measure horizontal and vertical spacing at the same time. Click the symbol and move your mouse to your target location.
• Horizontal (━): This will measure only horizontal spacing. Click the symbol and move your mouse pointer to your target location.
• Vertical (┃): This will measure only vertical spacing. Click the symbol and move your mouse pointer to your target location.
• Cancel interaction: Esc, ╳ or mouse click. Upon clicking the primary mouse button, the measurement is copied to the clipboard.

The controls on the toolbar can also be selected via Ctrl+1/2/3/4.

Tip

Scroll up with the mouse wheel to increase the threshold for pixel difference by 15 units per wheel tick. Effectively the measuring line can become longer. Scroll down to reverse.

Settings

From the Settings menu, the following options can be configured:

Setting	Description
Activation shortcut	The customizable keyboard command to turn the toolbar on or off.
Capture screen continuously during measuring	When off, the utility takes a single snapshot of your screen. When this is turned on, the utility will attempt real-time detection. Continuous mode will consume more resources when in use.
Per color channel edge detection	Test if all color channels are within a tolerance distance from each other. Otherwise, check that the sum of all color channels differences is smaller than the tolerance.
Pixel tolerance for edge detection	A value between 0-255. A higher value will provide a higher variation so it will be more forgiving with things like gradients and shadows.
Draw feet on the cross	Adds small, serif-like "feet" for additional visual recognition.
Line color	The color for the line that does the measuring.