I want to build an app which converts image formats. I was trying
convert an JPG image to BMP, while doing so i get OOM, cause app
memory is limited that its unable to use the array to store the image
for conversion. If this is the case, how there are apps which does the
same??
I don't know how the actual conversion has to look like, but in every case you will need a buffer or something like that, to consume the jpg. Because Android memory heap is between 24-48mb (one memory block) you run out of memory while trying to convert.
Memory of Android app is limited. The amount of available memory varies by device. So editing big images on an older device might be really a problem.
Solution to this is to use NDK. In NDK you can allocated much more memory than Java apps could have.
Related
Sometimes we encounter the memory issues,such as the OOM problems.And We inevitably have to manage the memory.Android has set a limit to the memory used bye each app.The maximum limit probably is the 32Min the early versions of android,such as 1.5,1.6,2.1.
Android of v4.0 has exceeded this limit.We can set android:largeHeap to "true" in the AndroidManifest,so the app could increase the memory limit.
I'm develeping the wallpaper app.The app can show many pictures in high definition.But the memory used by the app always reach the limit of more than 60M in the android of 720p, about 100M in the android of 1080p.
The overuse of memory is unacceptable for me.And I'm looking for the means to resolve it all the time.
My friends,How much memory your app will take up when you develop your app during debugging or running?Is there a memory-manage mechanism in the code?Look forward to your reply.
The amount of memory used by bitmaps is based on what's in the bitmap, not the size of the file. There's a few things you can do to reduce the footprint of the bitmap being loaded in to memory, which, in turn will reduce the amount of memory your app is using.
There's a great talk here from Google I/O for memory management that will help and another that will help you check to see if you have any memory leaks as well.
Also, note that if you use Bitmap.Config.RGB_565 you can half the amount of memory that the Bitmap is using (each pixel value is stored in 2 bytes instead of 4)
Guess what, another Android-Bitmap-OOM question!
Background
Whilst stress testing our application it has been noted that it is possible to max-out the app's process memory allocation after sustained, heavy usage (monkey runner like) with OutOfMemory exceptions being recorded within the ensuing stacktrace. The app downloads images (around 3 at a time) when a page under a ViewPager is selected. There can be 280+ images available for download when the length and breath of the app is exercised. The application uses Picasso by Square for it's image downloading abstraction. Notably, at no point in our application's code are we manipulating Bitmaps directly...we trust that the very talented Square Inc. employees are doing it better than we can.
Here is a picture
The below plot shows the heap allocations over time recorded under the dalvikvm-heap log message. The red dots indicates a user bringing a fresh set of articles into the application in order to bolster the amount of work outstanding and stress the app...
DALVIKVM heap allocations http://snag.gy/FgsiN.jpg
Figure 1: Nexus One heap allocations; OOMs occur at 80MB+
Investigation to-date
Against a Nexus S, Nexus 4, Wildfire, HTC Incredible and a myriad of further test devices, anecdotal testing has shown the memory management to be sufficient with the DVM GC 'keeping up' with the heavy lifting work being completed by the app. However, on high end devices such as the Galaxy S II, III, IV and HTC One the OOM are prevalent. In fact given enough work to do, I would imagine all of our devices would eventually exhibit the failure.
The question
There is clearly a relationship between screen density (our requested image sizes are based off the size of the ImageView), the process memory allocation and the number of images at a given size that would result in the app exceeding it's heap limits. I am about to embark on quantifying this relationship but would like the SO community to cast their eyes over this problem and (a) agree or disagree that the relationship is worth making and (b) provide literature indicating how best to draw up this relationship.
It is important to note that if we destroy the image quality our OOM all disappear but alas the UX is poorer which is why we are wanting to be dicing with the most effective use of the available heap.
Side note: Here is the portion of code responsible for loading these images into the views that have been laid out;
picassoInstance.load(entry.getKey())
.resize(imageView.getMeasuredWidth(),
imageView.getMeasuredHeight())
.centerCrop()
.into(imageView);
The 'dashing of image quality' mentioned above is simply dividing the imageView.getMeasured... by a number like '4'.
First you need to manage the memories allocation ,its a big issue in android as bitmaps takes lots of memories ,for that memory allocation can be reduce by following ways
put all those images which are huge in size to assets folder instead of putting them in drawabable folder . because drawable resources takes memory for caching them .if you load from asset folder the image will not cache .and will takes less memory .
study Lrucache which use for efficient memory management .
put resources in tiny formats for that check TinyPNG
if your images are too large in resolution , then try to use SVG files for images and load SVG file instead of image . check this SVG FOR ANDROID
finally i am not very good in English hope it may helps you.
This post is a little old but I also had this issue recently. Maybe this will help someone else.
General Overview of this massive thread/What helped me.
-Make sure you are using a Singleton Instance of Picasso
-Use fit()
-For large Images or many Images or when used in a FragmentPager/StatePager you should probably use skipmemorycache() and/or largeHeap declaration
Read the thread for more tips. At the time this question was posted nobody had posted this issue on picassos github.
https://github.com/square/picasso/issues/305
Background
android apps usually have a low amount of heap memory for them. that's why you always need to avoid holding large objects.
since the app i'm working on can get OOM on some cases, i thought that i should check out what causes the memory to be low.
i've used MAT plugin and i've found out that the app has 3 bitmaps that take 3.5MB each.
The problem
the app already has multiple bitmaps being used, but they are way smaller (less than 1MB each).
in fact i've even put breakpoints to make sure each bitmap i create don't take so much memory, and found nothing.
i've also watched some google IO videos (like this one) regarding this matter. it seems that in order to see which class has a reference to the object, you click on the object and choose "Path to GC roots"=>"exclude weak references".
What I've tried
you can see in the dominator-tree which bitmaps take the most (look at "retained heap").
in order to export the data, you can choose the byte array and then "copy"=>"save value to file".
however, like others have tried on this post , i'm stuck at showing the bitmap itself (need to know its format, width and height). plus it could be quite annoying to use GIMP for this task.
The question
how can i view the bitmaps (the image itself) within eclipse?
Haven't been able to find this one out.
How are Bitmaps stored in memory in Android? More specifically what I'm looking for is, does it store the information pixel by pixel, or does it use any sort of algorithm to reduce the number of stored pixels, like storing a single pixel and a number for how many times to repeat it in a row. I'm wondering about this because we're having trouble fitting all the images we want into our game. If it does use some sort of algorithm, then we can do something to the original image to cut down on memory consumption, right?
Bitmaps are stored compressed, but you pretty much can't display one without assembling the pixels at some point. Your best bet is probably to save your limited CPU heap and push your images into the GPU as compressed OpenGL ES textures.
Additional:
Have a look at Displaying Bitmaps Efficiently. Also recycle your bitmaps if it helps.
While an implementation may choose to use RLE to store bitmaps in memory, I very much doubt one would do so since it would be inefficient to operate with them.
On Android 3.0 and above, you can request a larger heap.
I am manipulating relative large images, about 5MP and sometimes even more. I need two copies of the images in memory for manipulation.
Now, the loaded images consume a lot of memory, more than available by the default Android heap which is 16MB respectively 24MB which results in the following error:
11-20 18:02:28.984: E/AndroidRuntime(7334):
java.lang.OutOfMemoryError: bitmap size exceeds VM budget
I need full resolution, thus downscaling while loading the images does not help.
What's the best solution to get over this problem? Are there built-in methods to dynamically load only chunks of bitmaps from storage? And can someone give me some hints how I can overcome the memory problem, e.g. by using specific caching strategies?
Regards,
You can allocate more memory in the ndk. You'd have to write native code to manipulate the images, or you'd have to figure out a way to allocate the image memory in native, then pass it back to Java.
Bitmap/Canvas use and the NDK
Another option might be to load a single image into memory, and break it up into chunks for processing. Save those chunks out to the file system. So, say you 2 large images. You load the first image, break it into 4 parts, save them, load the second, break it into 4 parts, save those, then load part #1 for each image, and do your thing. That implies you know that neither individual image is larger than the heap max, and that what you need to do is (basically) pixel level and doesn't need access to surrounding pixel data (you'll run into trouble at the edges if you need neighbor pixel info).
Without downsampling, splitting, or ndk, I don't know how you'd get more image data into memory. Perhaps lowering the color info. We do this in a product. Represent each pixel as 16 bits rather than 24 or 32. Our product is functional rather than "pretty", so the loss of color info wasn't a big deal.
You should watch this video on memory management: http://www.youtube.com/watch?v=_CruQY55HOk
At about 6 mins into it he covers the LargeHeap manifest option added to HoneyComb.