{"action":"created","issue":{"url":"https://api.github.com/repos/waveform80/picamera/issues/199","labels_url":"https://api.github.com/repos/waveform80/picamera/issues/199/labels{/name}","comments_url":"https://api.github.com/repos/waveform80/picamera/issues/199/comments","events_url":"https://api.github.com/repos/waveform80/picamera/issues/199/events","html_url":"https://github.com/waveform80/picamera/issues/199","id":58546197,"number":199,"title":"Overlay RGBA? Transparency not supported?","user":{"login":"jtkeyva","id":2954865,"avatar_url":"https://avatars.githubusercontent.com/u/2954865?v=3","gravatar_id":"","url":"https://api.github.com/users/jtkeyva","html_url":"https://github.com/jtkeyva","followers_url":"https://api.github.com/users/jtkeyva/followers","following_url":"https://api.github.com/users/jtkeyva/following{/other_user}","gists_url":"https://api.github.com/users/jtkeyva/gists{/gist_id}","starred_url":"https://api.github.com/users/jtkeyva/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jtkeyva/subscriptions","organizations_url":"https://api.github.com/users/jtkeyva/orgs","repos_url":"https://api.github.com/users/jtkeyva/repos","events_url":"https://api.github.com/users/jtkeyva/events{/privacy}","received_events_url":"https://api.github.com/users/jtkeyva/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-02-23T06:06:03Z","updated_at":"2015-03-13T15:58:58Z","closed_at":null,"body":"The overlay feature is nice, but couldn't figure out how to use png files with portions that are transparent. Is it possible to have a png as an overlay but with areas that are cut out?\r\nThanks"},"comment":{"url":"https://api.github.com/repos/waveform80/picamera/issues/comments/79075241","html_url":"https://github.com/waveform80/picamera/issues/199#issuecomment-79075241","issue_url":"https://api.github.com/repos/waveform80/picamera/issues/199","id":79075241,"user":{"login":"waveform80","id":1076190,"avatar_url":"https://avatars.githubusercontent.com/u/1076190?v=3","gravatar_id":"","url":"https://api.github.com/users/waveform80","html_url":"https://github.com/waveform80","followers_url":"https://api.github.com/users/waveform80/followers","following_url":"https://api.github.com/users/waveform80/following{/other_user}","gists_url":"https://api.github.com/users/waveform80/gists{/gist_id}","starred_url":"https://api.github.com/users/waveform80/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/waveform80/subscriptions","organizations_url":"https://api.github.com/users/waveform80/orgs","repos_url":"https://api.github.com/users/waveform80/repos","events_url":"https://api.github.com/users/waveform80/events{/privacy}","received_events_url":"https://api.github.com/users/waveform80/received_events","type":"User","site_admin":false},"created_at":"2015-03-13T15:58:58Z","updated_at":"2015-03-13T15:58:58Z","body":"At the moment, the overlay subsystem in picamera only uses RGB data with the renderer. In other words, alpha data is thrown away before passing the RGB buffer to the renderer. I've no idea if the renderer will accept an RGBA buffer; there is a format which suggests support for this but I don't know whether the firmware will take any notice of the alpha channel.\r\n\r\nIf anyone wants to play with this and find out, please do and report back! I think it's relatively easy - just play with the overlay class' MMAL format in picamera/renderers.py and feed the renderer something with 4 bytes per pixel instead of three."}}