Resolving Power

Table of content

• Test target template
• Start software
• Arrange toolbars
• Load images
• Adjust brightness
• Perform measurement
• Center determination (Line segment detector)
• Center determination (Phase shift)
• External color reference patterns

Test target template

The presented tool works for images depicting Siemens-stars. If you do not have images having a Siemens-star imaged you can find an example here. To include a Siemens-star test patttern in your next image-campaign you can download a scalable vector graphic template of a star here an have it print out.

Start software

If you never used MACS-BOX, here is how to open the software. Hint, the symbol may be hidden behind the upward pointing arrow in the lower right corner of your screen.

Arrange toolbars

You can arrange most toolbars to your liking and to ensure every item is visible.

Load images

Images can be loaded either by "drag 'n' drop", via "open dialog" or from "recent file list".

Adjust brightness

For a better location of the test patterns, brightness and gamma factor can be adjusted. This feature is for convenience only and does not affect the measurement.

Perform measurement

The measurement itself is implemented as a one-click solution. Use "CTRL" + left mouse button at estimated center postion.

Center determination (Line segment detector)

The center position should be refined. This procedure uses extracted lines of the Siemens-star to improve center coordinates. Simply press "o" on your keyboard after the initial measurement (see Perform measurement).

Center determination (Phase shift)

The center position should be refined. This procedure uses signal phase shift to improve center coordinates.

External color reference patterns

If the outermost ring does not contain pure black and white values it is strongly advised to use external color reference patterns if available.