# Bitmap with alpha

**URL:** https://forum.kirupa.com/t/bitmap-with-alpha/253212
**Category:** Uncategorized
**Created:** [February 28, 2008, 4:51am UTC](https://forum.kirupa.com/t/bitmap-with-alpha/253212 "2008-02-28T04:51:40Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![deluxmilkman](https://avatars.discourse-cdn.com/v4/letter/d/67e7ee/32.png) [@deluxmilkman](https://forum.kirupa.com/u/deluxmilkman)
#### Post date: [February 28, 2008, 4:51am UTC](https://forum.kirupa.com/t/bitmap-with-alpha/253212/1 "2008-02-28T04:51:40Z")

</div>

bitmap with alpha

hi, I have a dynamically attached bitmap (black and white),  
and trying to remove the black area from the bitmap.

also trying to change the bounding box of the mc according to the reduced size of my bitmap.

does anyone have any idea how?

```auto

var bmp:BitmapData = new BitmapData(160, 120);

bmp.draw(out);

var mc:MovieClip = this.createEmptyMovieClip("mc1",5);
	
mc.attachBitmap(bmp, 0);

```