Write bitmap to array instead of file stream in Android

Question

Currently, when I want to save a bitmap to disk I use:

bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);

Is it possible to have the data written to a byte array instead? I need to manipulate the data that goes to disk and not just the bitmap's image data. The jpg consist of additional stuff like metadata. I don't really care that it's a jpg. I'm not interested in what the data is but just to access the entire data that would normally get written to disk.

And remember that large Bitmaps could cause OutOfMemoryErrors - so careful with that. — Yaroslav Mytkalyk, Feb 07 '13 at 13:27
Shiv, can you post that as a solution instead of a comment please and I'll give you the checkmark. — Johann, Feb 07 '13 at 13:28
@AndroidDev-yeah i have posted it as an ans you can mark it if it helped you :) — Shiv, Feb 07 '13 at 13:43

Nermeen · Answer 1 · 2013-02-07T13:33:54.307

2

You can do it using:

public byte[] convertBitmapToByteArray(Bitmap bitmap) {
    ByteArrayOutputStream buffer = new ByteArrayOutputStream(bitmap.getWidth() * bitmap.getHeight());
    bitmap.compress(CompressFormat.PNG, 100, buffer);
    return buffer.toByteArray();
}

edited Feb 07 '13 at 13:33

answered Feb 07 '13 at 13:22

Nermeen

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That is wrong. You are creating an array the size of the image. The data written to disk contains, as mentioned, metadata and all the other stuff that goes into a jpg. Remove the sizing and it will work. – Johann Feb 07 '13 at 13:31

score 2 · Answer 2 · answered Feb 07 '13 at 13:42

2

If you wish to preserve the original pixel data (without compression), you can try this:

public byte[] bitmapToByteArray(Bitmap bitmap) {
    ByteBuffer byteBuffer = ByteBuffer.allocate(bitmap.getByteCount());
    bitmap.copyPixelsToBuffer(byteBuffer);
    return byteBuffer.array();
}

answered Feb 07 '13 at 13:42

Dheeraj Vepakomma

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That just copies the pixels and doesn't include the rest of the jpg information. – Johann Feb 07 '13 at 14:00
@AndroidDev you said in your question "I don't really care that it's a jpg.". – Dheeraj Vepakomma Feb 07 '13 at 14:03
I wrote "I need to manipulate the data that goes to disk and not just the bitmap's image data." - That was clear. It could be a png, jpg, whatever. – Johann Feb 07 '13 at 15:35

score 2 · Accepted Answer · answered Feb 07 '13 at 13:42

2

you can use this code :

      ByteArrayOutputStream out = new ByteArrayOutputStream();

                bMap.compress(Bitmap.CompressFormat.PNG, 100, out);
                byte[] imageArray = out.toByteArray();

answered Feb 07 '13 at 13:42

Shiv

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score -1 · Answer 4 · answered Feb 07 '13 at 13:36

U can try this.

if (Utility.isWifiPresent()
                    || Utility.isMobileConnectionPresent()) {
                URL url = new URL(fileUrl);
                InputStream iStream = url.openConnection().getInputStream();// .read(data)
                ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                byte[] tmpArray = new byte[1024];
                int nRead;
                while ((nRead = iStream.read(tmpArray, 0, tmpArray.length)) != -1) {
                    buffer.write(tmpArray, 0, nRead);
                }
                buffer.flush();
                data = buffer.toByteArray();
                FileOutputStream fOut = null;
        //path to store

                    fOut = Utility.getFileOutputStreamForCloud(
                            sdcardFolderPath, fileUrl);
                }
                fOut.write(data);
                fOut.flush();
                fOut.close();

Write bitmap to array instead of file stream in Android

4 Answers4