rdk graphic interface Transparency

It is not clear from your description on what you want to do. If you are referring to transparency/chroma keying it is supported in fbdev.Refer http://processors.wiki.ti.com/index.php/TI81XX_PSP_VPSS_Video_Driver_User_Guide Transparency Keying section

http://en.wikipedia.org/wiki/Chroma_keying

hi badri ,thanks for your help .

i mean that when i use osd link to create a image over the video like above image

but the "abcd" backgroud color for example is white,so if i want to just see the "abcd" over the video,not see the background color.so whether some parameters can be set  fix it ?

tks

You mean you want the SWOSD to automatically change font color such that it is in contrast with background video ?  It requires detection of contrast between background video and SWOSD font and switch font color if threshold is less than configured contrast.This is not supported  in SWOSD

i mean i creat a bmp file as a osd like following:

but now i want that when the image over the video ,i just want to see the words "aaaajlskfdlk",not see the oringe color