I have a method called loadFromCache and it returns a bitmap if it is found in the cache. Long story short I have it narrowed down to this method, returning null at the end if the try/catch fails.
FileInputStream fis = new FileInputStream(getCacheDir()+(""+position));
ObjectInputStream ois = new ObjectInputStream(fis);
Bitmap temp = (Bitmap)ois.readObject();
fis.close();
return temp;
I have previously tried the Bitmap.compress(...) methods to save bitmaps but they were a little slow for my needs... Yes the bitmap has been written to these positions, but I don't know if it (Bitmap) is serializable so is it actually saving? And yes I remembered to flush when I wrote the file.
How is Bitmap.compress() too slow for you? The only faster(?) way would be to write the bitmap unchanged to disk, see below.
Using MappedByteBuffer together with Bitmap.copyPixelsToBuffer() may work. I haven't tested this but it seems like it could work. Note that you most likely will have to store image dimensions yourself.
Sharing an experience I just had with Bitmap.compress being very slow:
My source image was a jpeg, and I was passing Bitmap.CompressFormat.PNG to bitmap.compress. This caused the compress operation to take 10-15 seconds.
Once I changed it to JPEG (such that the source and destination file remain the same image format) then the operation takes less than a second. Perhaps the original question came about through a similar means, and maybe someone else finds this helpful.
Related
I'm running into issues with the images in my gallery being much much larger than I need them to be.
I've looked for ways to reduce their size before I actually pull them in, but I'm just not quite putting it together as most of what I'm finding deals with BitMap resources and not a BitMap that already exists in the gallery.
So, basically, I am getting the image like so,
imageBitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
But before I actually assign it to my BitMap var over there I need to scale it down to a reasonable size for a phone.
Any help with understanding what is going on here better is appreciated.
getBitmap() is a weak convenience method. Its body is a whopping four lines of code:
public static final Bitmap getBitmap(ContentResolver cr, Uri url)
throws FileNotFoundException, IOException {
InputStream input = cr.openInputStream(url);
Bitmap bitmap = BitmapFactory.decodeStream(input);
input.close();
return bitmap;
}
This is why I don't bother teaching people about it.
IMHO, the best solution is for you to use one of the many image-loading libraries available for Android, such as Picasso. Most of the good ones can load from a Uri and handle your resizing as part of the operation, doing the heavy lifting on a background thread.
If, for whatever reason, you want to do all that work yourself, call BitmapFactory.decodeStream() with a BitmapFactory.Options object. In particular, set inSampleSize to indicate that you want the image to be resampled as part of reading it, so you wind up with a smaller Bitmap taking up less heap space.
I have been going crazy with this android error and from browsing the previous posts about this error none of the solutions that were given helped me.
I am of course talking about the all powerful killer known as the 'android Out of memory on a (NUMBER)-byte allocation.' I am trying to create a photo uploader and after the 3rd maybe 4th image my app crashes. I know to stop the crash to use a catch exception however that is not my problem. I am here to ask the community is there any solution to fixing this byte allocation error ?
Here is a snippet of my code involving the bit map .
String post = editTextPost.getText().toString().trim();
// get the photo :
Bitmap image = ((BitmapDrawable)postImage.getDrawable()).getBitmap();
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
// compress the image to jpg format :
image.compress(Bitmap.CompressFormat.JPEG, 45, byteArrayOutputStream);
byte[] imageBytes = byteArrayOutputStream.toByteArray();
String encodeImage = Base64.encodeToString(imageBytes,Base64.DEFAULT);
// Recycle bitmap :
image.recycle();
image=null;
// send data :
sendPost p = new sendPost(this);
p.execute(post, encodeImage);
imageBytes=null;
Im not using any libraries and would like to keep it that way however if using a library is the only option I will use one. Hopefully someone can help.
Bitmaps won't completely recycle if they are attached to a View, for example to a ImageView, if you do imageView.setImageBitmap(bitmap), you need to clear it before doing imageView.setImageBitmap(null) and clearing any other reference to any view.
After you finish uplloading the image release the memory occupied by the "postImage" -
postImage.setImageDrawable(null);
This will release any memory occupied by the bitmap associated with postImage
General Answer:
When you upload files you need to open a stream to your server and to
your file at same time. read and write chunk by chunk of 1 MB for
example. this way you will not get an out of memory exception.
I'm working on a project that needs to use a large image as a map. The image is about 95MB and has a resolution of 12100 x 8000 pixels.
I don't need the whole image at once, I just need a detail of 1000 x 1000 Pixel (it's not always the same detail, just grabbing the same part is not a solution I can use). So I can't just sample it down with the BitmapOptions.
I looked around and found the idea to create a FileInputStream (the image is on the SD-Card) and then I can just load the detail with decodeStream(InputStream is, Rect outPadding, BitmapFactory.Options opts). That way I wouldn't load the whole thing into the memory. I tried it, but it's just crashing when I try to load the image. Here's my code:
FileInputStream stream = null;
try {
stream = new FileInputStream(path);
} catch(Exception e) {
Log.e("inputstream",e.toString());
}
Rect rect = new Rect(a,b,c,d);
return BitmapFactory.decodeStream(stream, rect, null);
When I try to load the image, the activity closes and LogCat tells me java.lang.outOfMemoryError. Why does it crash? I thought with the stream it should work on the image "on-the-fly", but the only explication I have for the Error is the it trys to load the hole image into the memory. Does anybody have an idea how I can load the detail out of the image, or why this idea doesn't work?
It crashed because all these 95M are sucked into memory for processing. This call will not ignore parts of the stream - it will put the whole thing to memory and then try to manipulate it. The only solution you can have is to have some sort of server side code that does the same sort of manipulation or if you don't want to do it on server - provide thumbnails of your large image. And I would strongly advise against pulling whole 95M at any time anyways
Does BitmapRegionDecoder not help (I realise its level 10)?
I have tried working with a bit of code to decode a file from SD and then edit it. Because of this editing that needs to be done, keeping a higher scaled image is important. Some phones run into memory issues, whereas others have enough room in their heap to continue the decode without a set option.
//the following is ending a process in which a photo is taken and saved
//under "/sdcard/folder/photo.png"
FileOutputStream fos= new FileOutputStream(photo.getPath());
fos.write(jpeg[0]);
fos.close();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 4;
Bitmap originalFile = BitmapFactory.decodeFile("/sdcard/folder/photo.png",options);
I am basically looking into whether there is a way to almost set an if statement to put the option into place (if needed) otherwise continue without it.
As a workaround, wrap decoding into a try-catch and if "out of memory" exception happen, just catch it and try decode with properly set inSampleSize.
However, this looks more like a hack than a solution.
Basically, you need to know how much memory your decoded bitmap will take and how much memory is available for your application's heap to grow in the system right now.
First is easy to find out: width*height*4 bytes (by default decoding is in ARGB8888).
But I have no idea how to get the heap's memory size.
I read many discussions about the inSampleSize OutOfMemory dilemma.
Cannot get a good solution so i ask a question about it.
Im currently loading a bitmap with inSampleSize=4.
That will give me a Bitmap with the size 648x388.
Original On disk size is 2592x1592.
Im writing text on 648x388 bitmap and saving it back to disk.
Im writing on the 648x388 because the 2592x1592 give me OutOfMemory .
The way it works is that there can be 1-10 648x388 Bitmaps to be saved in a while loop.
I want to change this loop to save 1-10 2592x1592 Bitmaps.
How can i securely load the 2592x1592?
I don care about the resolution going down 60% or more.
As long as the Bitmap has the same size 2592x1592.
Is there a way to maybe keep the size but make Bitmap thinner,
removing color without making quality bad.
My first thought was going something like this to get the biggest bitmap i could get:
I have not tested this but get a feeling it's a bad way
boolean work = true;
int insample = 2;
BitmapFactory.Options options = new BitmapFactory.Options();
while(work){
try{
options.inSampleSize = insample;
bitmap = BitmapFactory.decodeFile(filePath,options);
work = false;
}catch(Exception e){
insample++;
}
}
any help would be grate.
Image processing requires a lot of memory. you cant use the whole bitmap and just modify it on your phone. use a web service for that. upload, process, download. sorry there is no other way a decoded bitmap just takes a lot of memory.
And by the way you cant catch an outOFMemory Exception. the app just crashes.
There's a hard limit on process size in Android and a 4 mega-pixel image at four bytes a pixel will hit it all by itself (on many devices), without any room for your program.
I think you are going to need to do one of two things: Create a web service to do the image processing on a server/in the cloud; or learn to do your image processing "on-the-fly" by manipulating the data directly instead of using a bitmap.