I'm working on a project that needs to use a large image as a map. The image is about 95MB and has a resolution of 12100 x 8000 pixels.
I don't need the whole image at once, I just need a detail of 1000 x 1000 Pixel (it's not always the same detail, just grabbing the same part is not a solution I can use). So I can't just sample it down with the BitmapOptions.
I looked around and found the idea to create a FileInputStream (the image is on the SD-Card) and then I can just load the detail with decodeStream(InputStream is, Rect outPadding, BitmapFactory.Options opts). That way I wouldn't load the whole thing into the memory. I tried it, but it's just crashing when I try to load the image. Here's my code:
FileInputStream stream = null;
try {
stream = new FileInputStream(path);
} catch(Exception e) {
Log.e("inputstream",e.toString());
}
Rect rect = new Rect(a,b,c,d);
return BitmapFactory.decodeStream(stream, rect, null);
When I try to load the image, the activity closes and LogCat tells me java.lang.outOfMemoryError. Why does it crash? I thought with the stream it should work on the image "on-the-fly", but the only explication I have for the Error is the it trys to load the hole image into the memory. Does anybody have an idea how I can load the detail out of the image, or why this idea doesn't work?
Does BitmapRegionDecoder not help (I realise its level 10)?