Crop: Rectangle how to get blurry transition

[ken_wawa]

I have quite long video with many crop:rectangle filters on some clips (sth. like 50 clips etc.). Lately I’ve noticed that this cropping is not too nice for eyes as it’s 0/1 type. I was wondering if I could easily add some blurry frame ex. for 5-10 pixels to make this transformation less “hard”. I could theoretically replace Crop:rectangle with Mask:Simple Shape but it would be quite time consuming as I would need to set once again all parameters. Moreover for this filter it’s not possible to set parameters with mouse on the video preview which would make it even more time consuming.

Is there any other, very simple way, to “add” some border softness parameter to crop:rectangle filter? Sure not as real parameter but to simulate it and if yes with which filter added later after crop:rectangle? Some kind of blur filter but not touching the whole area after crop:rectangle but ex. 10 pixels around frame?

[TimLau]

Alpha Channel: Adjust can help you to add blur around the Crop

[ken_wawa]

Oh yeah! That’s what I needed. Big thank you. Also Mode: Shrink Soft looks nice (depending what is needed for sure).

[ken_wawa]

One additional question - what this amount value means? Sure I feel its meaning but what is exactly? In particular if I have two different size cropped rectangles (ex. one 1000x500 and second 100x100) will the same amount in % give the same blurry frame size in pixels (ex. for both 10 pixels frame)?

[TimLau]

The same amount give the same effect and do not append on the size of the crop

50 % on both overlays

[Elusien]

@ken_wawa

what this amount value means? Sure I feel its meaning but what is exactly?

The actual frei0r source code documentation states:

Operation:
    select the operation to be done on the alpha channel. Currently
    there are seven choices: NO OP, Shave, Shrink hard, Shrink soft,
    Grow hard, Grow soft, Threshold and blur.
    "Shave" tries to remove the "hairy" stuff, and also shrinks the selection
    a bit.
    The "hard" operations introduce no new values to the alpha channel,
    so if you have a "hard" key (only 0 and 255) it will stay that way.
    The "soft" operations will introduce interpolated values, making
    the edge softer.
    NOTE: the shave, shrink and grow operations are quite slow, because they
    do many conditional operations on each pixel.
    "Blur" simply blurs the alpha channel with a quasi Gaussian blur.

Shrink/Grow/Blur amount:
    how far the shrinking/growing will extend, or the amount of blur.

[ken_wawa]

Thanks a lot.

I decided to use shrink_soft as blur has one very bad effect for me. If there are two rectangles which are overlaping, the common part look very bad when using blur (and quite ok when usink shring_soft).