computeIsOpaque

Returns true if all pixels are opaque. ColorType determines how pixels are encoded, and whether pixel describes alpha. Returns true for ColorType without alpha in each pixel; for other ColorType, returns true if all pixels have alpha values equivalent to 1.0 or greater.

For ColorType.RGB_565 or ColorType.GRAY_8: always returns true. For ColorType.ALPHA_8, ColorType.BGRA_8888, ColorType.RGBA_8888: returns true if all pixel alpha values are 255. For ColorType.ARGB_4444: returns true if all pixel alpha values are 15. For ColorType.RGBA_F16: returns true if all pixel alpha values are 1.0 or greater.

Returns false for ColorType.UNKNOWN.