Aliasing issue in filled path and fonts, even with Quality = true

Question

we’re facing an issue with aliasing in our RPM gauge implementation. Specifically, we’re using a filled path to draw a thin inner line based on the current RPM value. Even after setting the Quality property of the path to true, some aliasing is still visible, especially along angled or diagonal parts of the line. We’ve also noticed a similar aliasing effect with some characters English fonts in our UI, even when the Quality property is enabled.

Environment details:

• Hardware: i.MX RT1170

• Embedded Wizard version: 11.0

• Display resolution: 800×480

• Color format: RGB565

I’m attaching a screenshot from the Embedded Wizard documentation for reference where the curved edges are still having some aliasing. Could you from the team (or community) advise — apart from setting Quality to true, is there any other way to improve anti-aliasing for filled paths or fonts on this platform? Any additional properties, rendering options, or known workarounds would be really helpful.

Thanks in advance for any suggestions!

Answer 1

Hello,

some image or screenshot could help us to better understand the effect. Nevertheless, what you observe is probably caused by the display resolution and/or the reduced color space in RGB565. In particular the observation with fonts confirms the assumption. The fonts are stored as images already antialiased. There is no antialiasing performed at the runtime.

Test:  compare the image with the results in the prototyper.

What we can't rule it out is some HW issue. For example wiring in the display connection. This will very well result in some distorted screen contents like extra aliasing, etc.

Best regards

Paul Banach