Calculation Formula for memory usage of Android Bitmap, androidbitmap

Calculation Formula for memory usage of Android Bitmap, androidbitmap

Android definition of each resolution

Calculation method when the image is stored in ARGB_8888 format

Memory usage = image length * Image Width * 4 bytes

Image length = original image Length (Device DPI/folder DPI) Image Width = Original Image Width(Device DPI/folder DPI)

 

The example is as follows:

The image size is 200*320. The device is a red-meter dpi of 320 and belongs to an xhdpi device.

Verify that an image is placed in hdpi and the output result is as follows:

DD/MainActivity (13014): dpi: 320 bitmap ByteCount: 456036

Image length = (320/240) * 200 = 266.67

Image Width = (320/240) * 320 = 426.67

Memory usage = 266.67*426.67*4 = 455116 is roughly the same as the actual value

 

Verification 2: The image is placed under xxhdpi and the code output is as follows:

D/MainActivity (13014): dpi: 320 bitmap ByteCount: 113316

Image length = (320/480) * 200 = 133.33

Image Width = (320/480) * 320 = 213.33

Memory usage = 133.33*213.33*4 = 113774 is roughly the same as the actual value.