Visual Basic, Blending Pictures

Blending Pictures

Author	Message
Alex #1 / 3	Blending Pictures I have found two API to Alpha blend pictures together: the AlphaBlend API and the GdiAlphaBlend. The problem is that my two pictures are bitmaps of irregular shapes with a black background. When the red part of one shape blends with the black background from the other picture I get dark red when there should just be red. This is because it thinks the black part is part of the shape when it actually should be transparent. Take a look at this screen shot to see what I mean: http://www.--*.com/ Are there anyways to get around this? Or other ways to alpha bland images? Thanks, Alex
Mon, 05 Jul 2004 02:01:19 GMT

Howard Henry Schlunde #2 / 3	Blending Pictures If the dark red region should be bright red, then by the same logic, the green portions should be yellow. Are colors important? If they aren't, would a BitBlt SRCPAINT or SRCINVERT operation achieve the desired result? Howard Henry Schlunder Quote: > I have found two API to Alpha blend pictures together: the AlphaBlend API > and the GdiAlphaBlend. The problem is that my two pictures are bitmaps of > irregular shapes with a black background. When the red part of one shape > blends with the black background from the other picture I get dark red when > there should just be red. This is because it thinks the black part is part > of the shape when it actually should be transparent. Take a look at this > screen shot to see what I mean: > http://homepage.ntlworld.com/alex.spurling/Screenshot.gif > Are there anyways to get around this? Or other ways to alpha bland images? > Thanks, > Alex
Mon, 05 Jul 2004 04:57:28 GMT

pete #3 / 3	Blending Pictures all you've done is mixed colors. do-it-yourself method : b_Pixel = (Pixel_2 And &HFF) * shade + (Pixel_1 And &HFF) * (1. - shade) Or _ ((Pixel_2 And &HFF00&) * shade + (Pixel_1 And &HFF00&) * (1. - shade)) And &HFF00& Or _ ((Pixel_2 And &HFF0000) * (shade) + (Pixel_1 And &HFF0000) * ((1. - shade))) And &HFF0000 'Pixel_1' and 'Pixel_2' are the pixel colors of the two source images at the same destination x,y 'shade' is a blending factor (0.0 - 1.0) image_2 is superimposed on image_1, the 'shade' factor controls the translucency of image_2. shade=0.0 -> 100% translucency (destination image = image_1) pete Quote: > I have found two API to Alpha blend pictures together: the AlphaBlend API > and the GdiAlphaBlend. The problem is that my two pictures are bitmaps of > irregular shapes with a black background. When the red part of one shape > blends with the black background from the other picture I get dark red when > there should just be red. This is because it thinks the black part is part > of the shape when it actually should be transparent. Take a look at this > screen shot to see what I mean: > http://homepage.ntlworld.com/alex.spurling/Screenshot.gif > Are there anyways to get around this? Or other ways to alpha bland images? > Thanks, > Alex
Mon, 05 Jul 2004 23:19:29 GMT

Page 1 of 1

[ 3 post ]