Antialiasing images

[droida38]

It seems that whenever I add an image to my project, the image is antialialised. That may be very well using odinary pictures. But it also happens when I add an image to the effect tracks (V1 - V3) with the intent to use it as an overlay. This causes problems because the antialiased pixels are not removed.

Example: I add a simple image with black background and a white rectangle to track V1. I then set Overlay options -> Type = Color key, Soft edge = None, Color = 255,255,255.

I then select the white color.Now everything above the white pixels in track A+B is shown, BUT new gray (antialiased) pixels appear on the border between white and black, these are also shown as part of the resulting frame

I does'nt help to use 'Type = Alpha Channel'.

What to do?

Thanks in advance

[MikeGunter]

Hi,

Is this in the NTSC/PAL (you don't indicate where you are) or in the VGA monitor?

Mike

[MonroePoteet]

Is the image you're putting on V1 the same pixel aspect ratio as the target output? A few experiments shows that if I use a 640x480 mask image on V1, but my output resolution is 720x480, I get some edge artifacts, probably due to stretching the image to fit. Using a 720x480 mask image eliminates them and I get sharp edges in the output.

mTp

[droida38]

How stupid. I thought that I was using the same resolution, but instead of using 720x576 I was using 768x576... The little differences.

Thanks Monroe...

[MonroePoteet]

Not stupid at all. It's really easy for me to overlook stuff like that and pound my head on it for HOURS. Ah well, live and learn...

mTp

[videomartin]

droida38,

best will be to downsize the pictures to 768x576 and afterwards to set it to 720x576 (without downsizing). That should eliminate the stretching of the image on TV. Because the TV works with 768x576 and will enlarge the picture width again in the same way as the video, but the video has another pixel format.