CODEWITHSUNDEEP
androidbitmapandroid-bitmap
lorenzo-s
lorenzo-s

Reputation: 17010

How to check if a Bitmap is empty (blank) on Android

How can I check if a Bitmap object is completely blank, i.e. all its pixels are transparent, without a x-y loop on every pixel?

Upvotes: 24

Views: 23356

Answers (2)

Emanuel Adrian Lucaci
Emanuel Adrian Lucaci

Reputation: 41

You can do this very easy but it depends on the application. If you have an application that prompts the user for a drawing input, like signature or anything similar, you will usually have an ArrayList of Paths which are drawn to the Canvas of that View. You can do a check when you want to return the BitMap look to see if the ArrayList of Paths is bigger than 0 and return the BitMap if so, or else return null.

Upvotes: 0

lorenzo-s
lorenzo-s

Reputation: 17010

You can check your Bitmap instance (in the example myBitmap) against an empty one with:

Bitmap emptyBitmap = Bitmap.createBitmap(myBitmap.getWidth(), myBitmap.getHeight(), myBitmap.getConfig());
if (myBitmap.sameAs(emptyBitmap)) {
    // myBitmap is empty/blank
}

Upvotes: 45

Related Questions