如何在不压缩图像的情况下将图像转换为Base64字符串？

Question

Every time I update the same picture the image quality has been decreased by image compression method.

 public String BitMapToString(Bitmap bitmap) {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
    byte[] b = baos.toByteArray();
    base64Image = Base64.encodeToString(b, Base64.DEFAULT);
    return base64Image;
}

I don't want to compress image again and again. Please suggest something.

Answer 1

First of all using PNG compression will not lose image quality.

If you want to get the bytes without compression anyway, you can try the following:

ByteBuffer buffer = ByteBuffer.allocate(bitmap.getRowBytes() * bitmap.getHeight());
bitmap.copyPixelsToBuffer(buffer);
byte[] data = buffer.array();

To get Bitmap back from byte array:

Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(ByteBuffer.wrap(data));
return bitmap;