For my application I need to load a bitmap which sometimes can be really large. I'm getting OutOfMemory errors even on devices like galaxy S2. I searched around and found that I need to recycle the bitmap.
Previously I was loading the bitmap with BitmapFactory, creating a new scaled bitmap, and creating a bitmapdrawable all in one line. By doing this am I loading two bitmaps into memory? Should I create the initial bitmap and then recycle it after creating the scaled bitmap?
If the activity will be launched frequently should I load the bitmap once to a static field or should I recycle and recreate every time?
Thanks
Split the process into multiple steps. If you are measuring the bitmap against the available screen space and then loading a scaled bitmap, you can do the first step without loading the bitmap into memory using BitmapFactory.Options.inJustDecodeBounds. This will give you a Bitmap object without the pixel data but with the width and height properties. Then use that to decode your scaled bitmap using BitmapFactory.Options.inSampleSize.
Google these terms and you'll find tons of sample code doing just this. And yes, don't forget to recycle when you're done with a Bitmap.
https://www.google.com/#q=BitmapFactory+Options+inJustDecodeBounds+inSampleSize
Related
Whenever we need to rotate and resize a huge image file on Android (no bitmap allocated yet), the usual steps would be to first load the image into a resized bitmap, then do the rotation on another newly created bitmap.
If I do the rotation first I'll probably end with the dreaded OutOfMemoryError. This is quite logical and I'm OK with that.
Problem is, both approaches include having two bitmaps at once in memory at some point, and I'm on a tight memory budget here, even after implementing bitmap scaling as the official docs say (https://developer.android.com/topic/performance/graphics/load-bitmap). A typical implementation looks like this:
Bitmap bitmapResized = resizeBitmap(fSource, nTargetWidth, nTargetHeight);
Bitmap bitmapRotated = rotateBitmap(bitmapResized, nOrientation);
[recycle both bitmaps here]
Is there any way to do both steps at once in a memory lightweight fashion?
I have read about renderscript but I wasn't able to find code that does not take an already allocated bitmap.
There are a lot of examples how to use ViewPager as an image slider, but I haven't seen any that handle the problem of correctly rotated images:
Now actually I have a solution for this, but the problem is that the image sliding is painfully slow when the image size is over about 3000*1500 pixel because of the extra rotation step:
The ImageView itself doesn't care about the correct orientation when setting an image via
setImageURI or setImageBitmap.
This means you first have to find out the correct orientation yourself and then eventually do a
matrix.postRotate(rotation)
and create a new bitmap using
Bitmap.createBitmap(srcBitmap, 0, 0, srcBitmap.getWidth(),
srcBitmap.getHeight(), matrix, true);
This additional bitmap creation really slows it down.
If the was a method to load an image "rotated on the fly" ? Sth. like BitmapFactory.decodeStream(stream,matrix) ?
I have also tried to increase the ViewPager.setOffscreenPageLimit value to 3, but with
the result of "java.lang.OutofMemoryError: bitmap size exceeds VM budget" errors.
Somehow it must be possible because with the default "Gallery" app the sliding is really fast even with very large images...But I guess this not a trivial task ?
Finally I found the solution: to get a responsive, fast & fluid image sliding behaviour two things need to be done:
Do the bitmap loading in the background using AsyncTask
https://developer.android.com/training/displaying-bitmaps/process-bitmap.html
Load a downsampled version of the bitmap using BitmapFactory.Options.inSampleSize (calculated using the ratio between ViewPager's and the Bitmap's dimensions)
https://developer.android.com/training/displaying-bitmaps/load-bitmap.html
I'm currently downloading a bunch of thumbnails in memory as a bitmap, resizing the bitmap via Bitmap.createScaledBitmap, and then using the resized bitMap to populate a BitmapDrawable, which I subsequently load into an ImageView to display.
As you can imagine, with a couple of dozen images this can be quite slow. Does anyone have any suggestions on how I can speed this up? I've tried resizing the Drawable via .setBounds, but that doesn't seem to work.
edit I am loading the bitmap into a drawable because at some future point I wish to utilize layers to add some text overlays to the image prior to display
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Possible Duplicate:
OutOfMemoryError: bitmap size exceeds VM budget :- Android
In my application I load some little Bitmap(between 2k and 300k) that I affect to ImageViews, during the first launch of my App it works fine but when I quit it and relaunch it, I always have the OutOfMemoryError during a Bitmap creation.
Could somebody tell me why?
The problem is because your bitmap's size is too large than the VM can handle. For example from your code I can see that you are trying to paste an Image into imageView which you are capturing using Camera. So normally the camera images will be too large in size which will rise this error obviously. So as others have suggested, you have to compress your image either by sampling it or convert your image into smaller resolution. For example if your imageView is 100x100 in width and height, you can create a scaled bitmap so that your imageView gets filled exactly. You can do this for that,
Bitmap newImage = Bitmap.createScaledBitmap(bm, 350, 300,true);
And you have to recycle your bitmap and null your bitmap like this,
Bitmap bmap.recycle();
Bitmap bmap=null;
You should use bitmap.recycle() manually when you leave your activity.
Please refer to http://developer.android.com/reference/android/graphics/Bitmap.html#recycle()
I really doubt you have to use bitmap.recycle() if you null your references, allowing GC (but please prove me wrong).
I'd say it's more likely your bitmaps are too large, possibly aggravated by long lived Context references or somesuch.
I am joining two images using the code below but it throws an OutOfMemory error my images are around 1MB each.
private Bitmap overlayMark(String first, String second)
{
Bitmap bmp1, bmp2;
bmp1 = BitmapFactory.decodeFile(first);
bmp2 = BitmapFactory.decodeFile(second);
if (bmp1 == null || bmp2 == null)
return bmp1;
int height = bmp1.getHeight();
if (height < bmp2.getHeight())
height = bmp2.getHeight();
Bitmap bmOverlay = Bitmap.createBitmap(bmp1.getWidth() + bmp2.getWidth(), height,
Bitmap.Config.ARGB_8888);// Out of memory
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(bmp1, 0, 0, null);
canvas.drawBitmap(bmp2, bmp1.getWidth(), 0, null);
bmp1.recycle();
bmp2.recycle();
return bmOverlay;
}
Update: I tried below two answers but it still not allwoing me to create bitmap of such big size the problem is that the resultant bitmap is too large in size around 2400x3200 so its going out of memory.
How can I join large images without running out of memory?
Without loading the image into memory, you CAN get the size of the image, using inJustDecodeBounds. The Bitmap returns null, but all the parameters are set. You can scale down the image accordingly.
If your JPEG images are 1 MiB each, conversion to a BMP will take a lot of memory indeed. You can easily calculate its BMP equivalent by the dimensions of the image. Conversion of such a large image is expected to crash indeed. Android limits its apps to 16 MiB VM only.
Also use RGB_565 instead of ARGB_8888.
So your only solution is:
(a) To use BitmapFactory.Options.inSampleSize to scale down the image
or
(b) Use Android NDK where the 16 MiB limit isn't there.
I use this simple rule of the thumb:
the heavy lifting (both memory/CPU) is done on the server.
So write some servlet that takes the image, resizes it to a specified dimension (probably reduces the pixel depth too) and returns the result.
Piece of cake and it works on any mobile device you need.
Good luck!
I think a solution sort of like Sumon suggests might work.
Figure out the size of the final
image based on what will fit on the
screen.
Get the size of the first image using
the inJustDecodeBounds technique.
Figure out the size of the first
image in the final image. Calculate
re-sizing parameters.
Resize image, loading into memory.
Write resized image back to disk.
Recycle the bitmap. (This will help
when resizing the 2nd image)
Repeat for the second image, only you
can skip the writing to disk part.
Load first image.
If you only need to display, then just do that. If not then you can combine into a single bitmap at this point and write to disk. If this is the case, it may be difficult because you wil have essentially 2x the screen size in memory. In that case I would recommend resizing smaller. If you can't go smaller, then you will have to go the NDK route, thought I'm not sure how much that will help. Here's an amusing intro to the NDK and JNI. Finally, I would highly recommend developing this using a phone running Android 2.3+ since its use of heap-allocated bitmaps will make debugging much easier. More about those here.
It's not necessary that the space taken by in-memory representation of bitmaps correspond closely with file size. So even if you have 3mb memory available to jvm, you might still get OutOfMemoryException.
Your code is creating three in-memory images simultaneously. If you can find the size of both images without reading the complete files, you can modify the code in a way to have only one of the source images in memory at a time. If even that doesn't prove to be sufficient you might need some sort of streaming method of reading the images.
you may get some idea from here.
Are you trying to display this super large image or are you just trying to save it?
If your trying to display it. Cut the images into tiles. Then only display the tiles that are being viewed. If the user zooms out you need to reduce the size of the bitmap before showing the whole thing.
If your trying to save it, try saving it in sections to the same file by cutting the image up.
Loading 2 1m files in memory then creating a 2m file leaves you with 4M in memory for your images alone. Dynamically loading and unloading the memory solves this issue similar to tiles on Google maps or dynamic zooming in other map oriented solutions.
If you need to return that huge 2400x3200 bitmap as your result, there is no way to actually realize this goal. The reason is that 2400*3200*4 bytes ~ 30 Mb! How can you hope to implement this method, when even you can't even fit the return value into your limited heap space (ie 16Mb)?
And even if you used 16-bit color, it would still fail because you would end up using about 15MB, which would not leave you enough space for the language run time.