将位图转换为 byteArray android [英] Converting bitmap to byteArray android

问题描述

我有一个位图，我想通过将其编码为 base64 将其发送到服务器，但我不想将图像压缩为 png 或 jpeg.

I have a bitmap that I want to send to the server by encoding it to base64 but I do not want to compress the image in either png or jpeg.

现在我之前做的是.

ByteArrayOutputStream byteArrayBitmapStream = new ByteArrayOutputStream();
bitmapPicture.compress(Bitmap.CompressFormat.PNG, COMPRESSION_QUALITY, byteArrayBitmapStream);
byte[] b = byteArrayBitmapStream.toByteArray();
//then simple encoding to base64 and off to server
encodedImage = Base64.encodeToString(b, Base64.NO_WRAP);

现在我只是不想使用任何压缩，也不想使用来自位图中的任何格式的简单字节[]，我可以编码并发送到服务器.

Now I just dont want to use any compression nor any format plain simple byte[] from bitmap that I can encode and send to the server.

有什么指点吗?

推荐答案

您可以使用 copyPixelsToBuffer() 将像素数据移动到 Buffer，或者你可以使用 getPixels() 然后通过位移将整数转换为字节.

You can use copyPixelsToBuffer() to move the pixel data to a Buffer, or you can use getPixels() and then convert the integers to bytes with bit-shifting.

copyPixelsToBuffer() 可能是你想要使用的，所以这里是一个关于如何使用它的例子:

copyPixelsToBuffer() is probably what you'll want to use, so here is an example on how you can use it:

//b is the Bitmap

//calculate how many bytes our image consists of.
int bytes = b.getByteCount();
//or we can calculate bytes this way. Use a different value than 4 if you don't use 32bit images.
//int bytes = b.getWidth()*b.getHeight()*4; 

ByteBuffer buffer = ByteBuffer.allocate(bytes); //Create a new buffer
b.copyPixelsToBuffer(buffer); //Move the byte data to the buffer

byte[] array = buffer.array(); //Get the underlying array containing the data.

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