Adding Contour to a transparent .png silhouette?

[imgrafx]

Hi,

Newbie Xtreme user here.

I've imported a silhouette in .png format with transparent background. I want to apply a contour to it. How can I create a shape out of the silhouette so I can apply the contour. Everything I've tried has failed. Xtreme always recognizes the bounding box of the image with the transparency mask.

Is there a way to cut just the silhouette out, convert to shapes and apply the contour? I'm stumped. Any help is appreciated. Thanks.

Craig

[handrawn]

Hi welcome

it will always recognise the bounding box, because it is a bitmap - you need to make a vector shape from it

use the shape editor tool to trace around the silhouette - that gives you a vector shape same as the silhouette

or you could use the bitmap trace tool - assuming it is a silhouette in the strict sense of the word that should work ok - but you will have to experiment with the settings to get it right

[molucca]

If you try to trace, make a black and white image without transparency. The trace function will see the alpha channel and the entire trace will be black.

Then ungroup the trace and delete the white background. You may want to use the shape edit tool to select the nodes and use smoothing to reduce the number of nodes.

Then you will have a vector object.

In Photoshop, you could load the selection from the alpha channel, and convert the selection to a path. I don't have any idea if you could use a saved path that way. Maybe a good question.

Just my view of things.

Rich

[handrawn]

thats true Rich - xara doesn't ignore alpha channels when bitmap tracing - I've spent to much time with inkscape

[imgrafx]

Thanks for the ideas!

Rich, I tried the trace before and it did turn out entirely black. I'll make a black and white image as you said and try that.

Sure appreciate the help. Thanks guys!

Craig

[molucca]

Steve,

You could make your silhouette a color other than black. A full transparent alpha channel would be full black, and you would have a separation. Something like a black and white JPG would have a small transition zone at the edge of the silhouette, and you may get fragments around the edge. Maybe a PNG/ alpha wouldn't do that because there would not be an edge transition. Worth trying.

Rich

[imgrafx]

Rich,

Just tried your suggestion and it worked pretty good. Easy too. Just need to fine tune some nodes around the resulting shape. Thanks!

Craig

[molucca]

Having a transparent image appear full transparent doesn't mean there isn't anything there. To me, it just means you cannot see what may be there. The example of the foxtail would appear in Xara to be full transparent, and you wouldn't see the extraneous pixels. I have an application that displays PNGs differently and I can see the pixel clouds. A vector separation in Xara gives a transparent area free of extraneous pixels. If I used a red outline object to make a clipview, I would see a PNG wth a red outline around the graphic. You probably wouldn't see it in Xara, however. So, tracing a PNG may give unexpected results.

Rich

[handrawn]

no indeed - its just using 32bits instead of 24bits to define the image

the 24bit info defines each pixel as a hex value between 00 00 00 and FF FF FF

the additional 12 bits enables definition for each pixel of an amount of transparency between 00 and FF [fully transparent to fully opaque]

this is easier IMO in an application [eg inkscape] which uses a full 32bits to define color ie 00 00 00 00 to FF FF FF FF [RGBA rather than RGB]

xara doesn't work this way internally - sometimes it shows - not a problem as long as you know how it does work


my understanding, anyhow

[molucca]

Steve,

You can control the color of the most background object by setting the color at the bottom of the image. This may be of use at times.

Rich