您可以将不可变位图转换为可变位图。
我找到了一种仅使用一个位图的内存的可接受解决方案。
将源位图原始保存（RandomAccessFile）到磁盘上（没有ram内存），然后释放源位图（现在，内存中没有位图），然后，文件信息将加载到另一个位图。通过这种方式，可以制作一次仅在内存中存储一个位图的位图副本。
在此处查看完整的解决方案和实现：Android：将不可变位图转换为可变
我对该解决方案进行了改进，现在可以与任何类型的位图（ARGB_8888，RGB_565等）一起使用，并删除临时文件。看我的方法：
/*
* Converts a immutable bitmap to a mutable bitmap. This operation doesn’t allocates
* more memory that there is already allocated.
*
* @param imgIn - Source image. It will be released, and should not be used more
* @return a copy of imgIn, but muttable.
/
public static Bitmap convertToMutable(Bitmap imgIn) {
try {
//this is the file going to use temporally to save the bytes.
// This file will not be a image, it will store the raw image data.
File file = new File(Environment.getExternalStorageDirectory() + File.separator + “temp.tmp”);
//Open an RandomAccessFile //Make sure you have added uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" //into AndroidManifest.xml file RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw"); // get the width and height of the source bitmap. int width = imgIn.getWidth(); int height = imgIn.getHeight(); Config type = imgIn.getConfig(); //Copy the byte to the file //Assume source bitmap loaded using options.inPreferredConfig = Config.ARGB_8888; FileChannel channel = randomAccessFile.getChannel(); MappedByteBuffer map = channel.map(MapMode.READ_WRITE, 0, imgIn.getRowBytes()*height); imgIn.copyPixelsToBuffer(map); //recycle the source bitmap, this will be no longer used. imgIn.recycle(); System.gc();// try to force the bytes from the imgIn to be released //Create a new bitmap to load the bitmap again. Probably the memory will be available. imgIn = Bitmap.createBitmap(width, height, type); map.position(0); //load it back from temporary imgIn.copyPixelsFromBuffer(map); //close the temporary file and channel , then delete that also channel.close(); randomAccessFile.close(); // delete the temp file file.delete();} catch (FileNotFoundException e) { e.printStackTrace();} catch (IOException e) { e.printStackTrace();}return imgIn;}
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