Utils.bitmapToMat converts an Android Bitmap to an OpenCV Mat. It requires a bitmap of type ARGB_8888 or RGB_565. import org.opencv.android.Utils; Mat mat = new Mat(); Bitmap bmp32 = bmp.copy(Bitmap.Config.ARGB_8888, true); Utils.bitmapToMat(bmp32, mat);
When showing Bitmap in ImageView from a file first decode it with the help of BitmapHelper.decodeFile(picturePath, 200, 200, true) this will return compressed Bitmap so that while encoding this Bitmap you can handle high resolution images as well as heavy size images upto 100 MB of file. After decoding file set it to your ImageView … Read more
In your onDestroy method you could try something like this: ImageView imageView = (ImageView)findViewById(R.id.my_image); Drawable drawable = imageView.getDrawable(); if (drawable instanceof BitmapDrawable) { BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable; Bitmap bitmap = bitmapDrawable.getBitmap(); bitmap.recycle(); } The cast should work since setImageBitmap is implemented as public void setImageBitmap(Bitmap bm) { setImageDrawable(new BitmapDrawable(mContext.getResources(), bm)); }
Keep in mind, that is a LOT of memory you are trying to allocate with that Bitmap. Refer to http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/37684999-62c7-4c41-8167-745a2b486583/ .NET is likely refusing to create an image that uses up that much contiguous memory all at once. Slightly harder to read, but this reference helps as well: Each image in the system has the … Read more
I have modified the code provided by abalta to accept bitmaps in realtime (ie you don’t already need to have the bitmaps saved to disc). It also has a performance improvement since you don’t need to write then read the bitmaps from disc. I also increased the TIMEOUT_USEC from the original example which fixed some … Read more
A little more detail… I posted earlier this evening with a consolidation and small addition to what had been said on this page – that can be found at the bottom of this post. I am editing the post at this point, however, to post what I propose is (at least for my requirements, which … Read more
explanation the sample code shows how to store 2 different bitmaps (small ones, but it’s just a demo), recycle the original java ones, and later restore them to java instances and use them. as you might guess, the layout has 2 imageViews. i didn’t include it in the code since it’s quite obvious. do remember … Read more
Documentation and public source code is not pushed yet to Google’s git. So my research is based only on partial information, some experiments, and on my own experience porting JVM’s to various devices. My test created large mutable Bitmap and copied it into a new HARDWARE Bitmap on a click of a button, adding it … Read more
.NET is a managed environment: specifically, memory allocation is usually managed on your behalf by the .NET runtime. You don’t typically need to allocate the memory yourself. Sometimes, however, you do need to inform the runtime when you’ve finished with memory by using Close() or Dispose(). The using statement can be used to wrap a … Read more
Its safe if you marshal.copy data rather than setting scan0 (directly or via that overload of BitMap()). You don’t want to keep managed objects pinned, this will constrain the garbage collector. If you copy, perfectly safe. The input array is managed and can be moved by the GC, scan0 is an unmanaged pointer that would … Read more