Is it possible to create image programmatically on Java, Android?

Question

I need to create .jpeg/.png file on my Android application programmatically. I have simple image (black background), and it need to write some text on it programmatically. How can I do it? Is it possible?

Answer 1

It's definately possible.

To write text on an image you have to load the image in to a Bitmap object. Then draw on that bitmap with the Canvas and Paint functions. When you're done drawing you simply output the Bitmap to a file.

If you're just using a black background, it's probably better for you to simply create a blank bitmap on a canvas, fill it black, draw text and then dump to a Bitmap.

I used this tutorial to learn the basics of the canvas and paint.

This is the code that you'll be looking for to turn the canvas in to an image file:

OutputStream os = null; 
try { 
    File file = new File(dir, "image" + System.currentTimeMillis() + ".png");
    os = new FileOutputStream(file); 
    finalBMP.compress(CompressFormat.PNG, 100, os);
    finalBMP.recycle(); // this is very important. make sure you always recycle your bitmap when you're done with it.
    screenGrabFilePath = file.getPath();
} catch(IOException e) { 
    finalBMP.recycle(); // this is very important. make sure you always recycle your bitmap when you're done with it.
    Log.e("combineImages", "problem combining images", e); 
}

Answer 2

Yes, see here

Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);

You can also use awt's Graphics2D with this compatibility project