Moho Forum

Hey everyone,

Very basic question I guess, but -- would there be a way to blur only a part of an imported bitmap image in ASP11 please ?
I tried to use masked layers and cropped bitmap duplicates (as for smooth joints for multiple bone pairs for instance), but it didn't work.

Any clues ? I am currently using ASP for a series of illos and it would help me for some of them.

several ways to do this. for example -- do the duplicate and set layer blur in just one -- e.g. to show a foreground object in focus with bg blurred

group mask hide all
>imagecopy - mask this layer
>mask - add to mask (soft edge shape??)
image - layer blur > 0

Thanks Hayasidist!

Yes my first thought was indeed to create a group folder, apply a soft-edged vector mask on the region to blur, and duplicate of the bitmap image to put it underneath the mask. And it somehow does work indeed, yet only if the blurred duplicate is very light (no more than 1) :



As soon as the blur increases, both images are starting to overlap and the trick shows though :



If any other method is available (apart from tracing the bitmap image please), I am longing to know how to proceed.

Have you tried to also heavily blur the mask, or mabe use an alpha gradient?

Yes I have, but it doesn't change much :

Here is what we have with the mask blurred with a value of 20 :



And with an aditional alpha value of 128 applied to the mask :



Also thought of rotating the bitmap image on the Y axis, but the not-really-3D / 2.5D space not only deforms the bitmap image too much, but it also doesnt work even with the depth of field turned on.

Masking with a gradient works here:


The difference between left and right is that the left bitmap shows a sharp edge even in the blurred part. That's because the unblurrred bitmap lies under the blurred version. On the right I masked both versions, looks better, but it's tricky to place the gradients to overlap and not have a semi-transparent part in the middle (which I have).

AS file is here: http://www.slowtiger.de/examples/blurmask.zip.

cableon wrote:... create a group folder, apply a soft-edged vector mask on the region to blur...

what I did was the opposite of that -- the masked layer was the area NOT blurred -- and the base layer was the blurred area -- and the test result I got was very acceptable but I did first have a relatively large image.

When I tried again with a 128px square .bmp I used a second pass masking to remove the base layer blur from the sharp area -- keeping the sharp area on top of the blurred and that looked ok.

It works, but I recommend doing such a blur in Photoshop.

I'm guessing that the OP asked for a "how to in AS" because they want to animate the (area of) blurring??

but, agreeing with slowtiger -- creating a blurred version of the whole image in PS then using an animated mask for selective reveal ...


The issue, I think, with the soft edge mask is that if the object is very small, and by implication so is the masking shape, then as the soft edge extends inwards as well as outwards, the overall opacity of the mask is reduced -- that's why the image appears lighter. A way round that would be to use soft edge only on a stroke. Also, if the images are against a zero-alpha background, then it's still necessary to mask out that part of the burred image that will surround the "sharp focus" area.

I did try in AS, with a duplicate at a different z but scaled to preserve visual size with depth of field enabled and then mask in /out as above and that seemed ok too.

Thanks a lot for your advice Hayasidist and Slowtiger! And my apologize for answering so late.

I was actually planning to show my own process through a video screencapture, which ended up turning into a slightly longer piece, that took a bit longer than expected to build up, hence the delay... Here it is though :



The purpose of that short animated making-of is to present the working process of most illustrations on L'Amicale des Termites (ie The Termites Fellowship) -- an illustrated, French/English wordbook online set up in collaboration with French artist Gaëlle Maas.

Because of such a belated answer, and since my first intent was to post it here, I am "premiering" it on the Lostmarble forum first, instead of putting it on the Amicale's website first.

It should be up on the Amicale's blog too in a bit though, related to the concerned article's page.

Hope you like it, and thanks again for your kind support!