Screen recording is not so sharp

[newbie-02]

@ koala:

great!, I love your fundamental knowledge.

And pls. be tolerant with my slowly growing experience, it's just too many settings at too many points
where it's unclear which does what and if it works ... e.g. there are additional scaling settings in the
screen capture device ... all very confusing.

And I found one more player in the game, having anti aliasing active I get - wanted - shaded seams around
text, but they are - unwanted - colored, the pixels left of black are yellow/red/brown, while to the right they are
more blue, see pics below.

Anyone a hint on that? ( I know here is windows and I'm on linux, but already if windows has similar will
bring my knowledge up )

Funny to see: special parts like the part of the cross in pic_06 and the I between 1 and T in pic_07 which form the cursor are not affected.

best regards, b.

pic_06 unwanted colored anti aliasing:

pic_07 unwanted colored anti aliasing:

 

[koala]

I observed these brown/blue colored pixels with Windows Truetype font rendering. They're intentionally generated by the font engine, not by some video encoder. These implement partial pixel, 3/4, 2/4, 1/4 pixel. For round shapes, they act as anti-aliasing to make the shape more smooth. This l without any round shape also contains them, and this is probably because of character spacing.

According to the font engine, each character has its own calculated intended position. This position doesn't necessarily match the pixel grid. If this l is located at pixel position 1.75, this means it's drawn 1/4 pixel left of position 2. So the l starts with one pixel column that has 25% saturation (implemented by a brown shade) and it ends with a pixel column with 75% saturation, which is implemented by a blue shade. If you look at this from some distance, the l as a whole appears at the calculated position 1.75.

It's no undesired artifact or effect, it's exactly what is intended and the result of many years of font rendering development. Because of this, modern font renderings appear so smooth and proper. If you compare this to font renderings from 20 years ago, you will see those renderings are often more rough, more unsteady, not 100% perfectly spaced.