InterpolationMode.High

Question

I am trying to figure out the difference between High and HighQualityBicubic InterpolationMode in .Net (System.Drawing.Drawing2D.InterpolationMode.High).

Does High mean that it will pick the best algorithm based on the image and what you are doing with it? Is it just an alias for HighQualityBicubic? Something else?

According to the MSDN documentation,

High - Specifies high quality interpolation.

HighQualityBicubic - Specifies high-quality, bicubic interpolation. Prefiltering is performed to ensure high-quality shrinking. This mode produces the highest quality transformed images.

Answer 1

There are a lot of seemingly duplicate entries like this in .NET, especially System.Drawing. I imagine they're there for possible future additions. HighQualityBicubic specifically requests Bicubic, whereas High will use the best available at the time.

Someone might discover a super-awesome resizing algorithm tomorrow that puts all other before it to shame. High would allow .NET.NEXT to use that.

Just a theory, though. There's probably docs on it somewhere, but it's bedtime ;)

Answer 2

I set Graphics.InterpolationMode and read back its value for every possible value.

I found that Default and Low become Bilinear, and that High becomes HighQualityBicubic.