Develop Reference

Why is Bitmap loading still so slow even with Google's implementation?

I use these two functions, slightly modified from Google's code in the Android docs to use filepaths:
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromFilePath(String pathName, int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(pathName, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(pathName, options);
}
With the idea being to use a scaled-down version of the Bitmap to be mapped onto an ImageView rather than the full-thing, which is wasteful.
mImageView.setImageBitmap(decodeSampledBitmapFromFilePath(pathToFile, 100, 100));
I implemented a thing where you press a button and it rotates to the next image, but there's still a significant lag (it takes a moment for the ImageView to populate) on my phone compared to my emulator. And then occasionally my phone app will crash and I can't replicate it on my emulator.
Is there a problem with this code I've posted above? Is there a problem with the way I am using the code?
Example:
public void reloadPic() {
new Thread(new Runnable() {
#Override
public void run() {
final Bitmap bm = decodeSampledBitmapFromFilePath(filepath, mImageViewWidth, mImageViewHeight);
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
mImageView.setImageBitmap(bm);
}
});
}
}).start();
}

Your code is jumping between threads several times. First you launch a thread. Then you wait for it to be scheduled You decode on that thread. Then you post a command to the UI thread and wait for it to be scheduled. THen you post a draw command to the ui thread (that's part of what setImageBitmap does). Then you have to process any other commands that came in first. Then you actually draw the screen. There's really only 3 ways to speed this up:
1) Get rid of the thread. You shouldn't decode lots of images on the UI thread, but decoding 1 isn't too bad.
2)Store the images in the right size to begin with. This may mean creating thumbnails of the images ahead of time. Then you don't need to scale.
3)Preload your images. If there's only one button and you know what image it will load, load it before you need it, so when the button is pressed you have it ready. Wastes a bit of memory, but only 1 image worth. (This isn't a viable solution if you have a lot of possible next images).

BitmapFactory.decodeStream out of memory despite using reduced sample size

I have read many related posts concerning memory allocation problems with decoding bitmaps, but am still unable to find the solution to the following problem even after using the code provided in the official website.
Here is my code:
public static Bitmap decodeSampledBitmapFromResource(InputStream inputStream, int reqWidth, int reqHeight) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len;
try {
while ((len = inputStream.read(buffer)) > -1) {
baos.write(buffer, 0, len);
}
baos.flush();
InputStream is1 = new ByteArrayInputStream(baos.toByteArray());
InputStream is2 = new ByteArrayInputStream(baos.toByteArray());
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(is1, null, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
options.inPurgeable = true;
options.inInputShareable = true;
options.inJustDecodeBounds = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
return BitmapFactory.decodeStream(is2, null, options);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee
// a final image with both dimensions larger than or equal to the
// requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}
bitmap = decodeSampledBitmapFromResource(inputStream, 600, 600);
I am getting "Out of memory error on a 3250016 - byte allocation" in this line:
return BitmapFactory.decodeStream(is2, null, options);
It would seem to me that 3.2 MB is small enough to be allocated. Where am I going wrong? How can I solve this?
EDIT
After looking into this solution HERE by N-Joy it works fine with Required size 300 but my required size is 800, so i am still getting the error.

The method decodeSampledBitmapFromResource is not memory efficient because it uses 3 streams: the ByteArrayOutputStream baos, ByteArrayInputStream is1 and ByteArrayInputStream is2, each of those stores the same stream data of the image (one byte array for each).
And when I test with my device (LG nexus 4) to decode an 2560x1600 image on SDcard to target size 800 it takes something like this:
03-13 15:47:52.557: E/DecodeBitmap(11177): dalvikPss (beginning) = 1780
03-13 15:47:53.157: E/DecodeBitmap(11177): dalvikPss (decoding) = 26393
03-13 15:47:53.548: E/DecodeBitmap(11177): dalvikPss (after all) = 30401 time = 999
We can see: too much memory allocated (28.5 MB) just to decode 4096000 a pixel image.
Solution: we read the InputStream and store the data directly into one byte array and use this byte array for the rest work.
Sample code:
public Bitmap decodeSampledBitmapFromResourceMemOpt(
InputStream inputStream, int reqWidth, int reqHeight) {
byte[] byteArr = new byte[0];
byte[] buffer = new byte[1024];
int len;
int count = 0;
try {
while ((len = inputStream.read(buffer)) > -1) {
if (len != 0) {
if (count + len > byteArr.length) {
byte[] newbuf = new byte[(count + len) * 2];
System.arraycopy(byteArr, 0, newbuf, 0, count);
byteArr = newbuf;
}
System.arraycopy(buffer, 0, byteArr, count, len);
count += len;
}
}
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(byteArr, 0, count, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth,
reqHeight);
options.inPurgeable = true;
options.inInputShareable = true;
options.inJustDecodeBounds = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
int[] pids = { android.os.Process.myPid() };
MemoryInfo myMemInfo = mAM.getProcessMemoryInfo(pids)[0];
Log.e(TAG, "dalvikPss (decoding) = " + myMemInfo.dalvikPss);
return BitmapFactory.decodeByteArray(byteArr, 0, count, options);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
The method that does the calculation:
public void onButtonClicked(View v) {
int[] pids = { android.os.Process.myPid() };
MemoryInfo myMemInfo = mAM.getProcessMemoryInfo(pids)[0];
Log.e(TAG, "dalvikPss (beginning) = " + myMemInfo.dalvikPss);
long startTime = System.currentTimeMillis();
FileInputStream inputStream;
String filePath = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/test2.png";
File file = new File(filePath);
try {
inputStream = new FileInputStream(file);
// mBitmap = decodeSampledBitmapFromResource(inputStream, 800, 800);
mBitmap = decodeSampledBitmapFromResourceMemOpt(inputStream, 800,
800);
ImageView imageView = (ImageView) findViewById(R.id.image);
imageView.setImageBitmap(mBitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
myMemInfo = mAM.getProcessMemoryInfo(pids)[0];
Log.e(TAG, "dalvikPss (after all) = " + myMemInfo.dalvikPss
+ " time = " + (System.currentTimeMillis() - startTime));
}
And the result:
03-13 16:02:20.373: E/DecodeBitmap(13663): dalvikPss (beginning) = 1823
03-13 16:02:20.923: E/DecodeBitmap(13663): dalvikPss (decoding) = 18414
03-13 16:02:21.294: E/DecodeBitmap(13663): dalvikPss (after all) = 18414 time = 917

This is a common issue which user normally faces while playing with large bitmaps and there are lots a questions discussed on site, here, here, here and here and many more, even though user not able to manipulate the exact solution.
I stumbled upon a library sometime back which manages bitmaps smoothly and others links which I listed below. Hope this helps!
smoothie-Library
Android-BitmapCache
Android-Universal-Image-Loader
Solution for OutOfMemoryError: bitmap size exceeds VM budget

ARGB_8888 uses more memory as it takes Alpha color value so my suggestion is to use RGB_565 as stated HERE
Note: Quality will be little low compared to ARGB_8888.

You're probably holding on to previous bitmap references. I'm guessing that you're executing this code several times and never executing bitmap.recycle(). Memory will inevitably run out.

I had many problems with Bitmap memory usage.
Results:
Most devices have limited heap memory for graphics, most small devices are limited to 16MB for overall apps, not just your app
Use 4 bit or 8 bit or 16 bit bitmaps if applicable
Try to draw shapes from scratch, omit bitmaps if possible.

Use WebView to dynamically load as many images as you like, it's built using NDK (low level) so has no GDI heap memory restrictions.
It works smooth and fast :)

Out of memory problems when decoding bitmaps are not often linked with the image size you are decoding.
Of course if you try to open an image 5000x5000px you will fail with a OutOfMemoryError, but with the size of 800x800px it is totally reasonable and should work fine.
If your device is out of memory with a 3.2 MB image it's likely because you are leaking context somewhere in the app.
It's the first part of this post:
I guess problem is not in your layout, problem is somewhere else in
your code. and probably you are leaking context somewhere.
What it means it's that you are using Activity Context in components that should not, preventing them to be garbage collected. Because there components often are held by activities, those activities are not GC and your java heap will grow very fast and your app will crash at one time or another.
As Raghunandan said, you will have to use MAT to find wich Activity/Component is held and remove the context leak.
The best way I found for now to detect context leak is orientation change.
For example, rotate your ActivityMain multiple times, run MAT and check if you have only one instance of ActivityMain. If you have multiple ones (as much as rotation changes) it means there is a context leak.
I found years ago a good tutorial on using MAT. Maybe there is better one now.
Other posts on memory leaks:
Android - memory leak or?
Out of memory error on android emulator, but not on device

Have a look at this video. http://www.youtube.com/watch?v=_CruQY55HOk. Do not use system.gc() as suggested in the video. Use a MAT Analyzer to find out memory leaks. The returned bitmap is too huge causing memory leak i guess.

It seems you have large image to display.
You can download image and save to sdcard (example) then you can user this
code to display image from sdcard.

i also had same problem earlier.. and i have managed it by using this function where you can get scale as your required width and height.
private Bitmap decodeFile(FileInputStream f)
{
try
{
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(f,null,o);
//Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE=70;
int width_tmp=o.outWidth, height_tmp=o.outHeight;
int scale=1;
while(true)
{
if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
break;
width_tmp/=2;
height_tmp/=2;
scale*=2;
}
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(f, null, o2);
}
catch (FileNotFoundException e) {}
return null;
}
and refer Memory Leak Error Android and error in loading images to gridview android

Change image to a picture in Gallery

I am working on an application that needs to obtain a random picture from the android device's built-in picture gallery and then display it on the screen. Here's what I have to work with:
-An ImageView object called picture
-The ID, TITLE, DATA, MIME_TYPE, and SIZE of the picture I want to display
I think the problem is I don't know what information I need to put in this line:
picture.setImageResource(???);
Here's all my code to give you some idea of what I'm trying to do:
public void generateImage() {
// Get list of images accessible by cursor
ContentResolver cr = getActivity().getContentResolver();
String[] columns = new String[] {
ImageColumns._ID,
ImageColumns.TITLE,
ImageColumns.DATA,
ImageColumns.MIME_TYPE,
ImageColumns.SIZE };
Cursor cursor = cr.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
columns, null, null, null);
// Collect Picture IDs
cursor.moveToFirst();
ArrayList<Integer> picList = new ArrayList<Integer>();
while (!cursor.isAfterLast()) {
picList.add(cursor.getInt(0));
cursor.moveToNext();
}// end for
// Generate random number
int imageCount = picList.size() - 1;
Log.d("NUMBER OF IMAGES", "Image Count = " + imageCount);
Random random = new Random();
int randomInt = random.nextInt(imageCount);
// Extract the image
int picID = picList.get(randomInt);
picture.setImageResource(picID);
}// end Generate Image
Anybody have any idea what I need to do in order to set the picture object to the picture that I have from the gallery (preferably using the information I've already obtained)?

Looks like you are saving an array of the cursor position... that would probably not give you much to work with. I think you'd rather populate an ArrayList with ImageColumns._ID and then use that string as a URI to open the image.

//Extracting the image
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToPosition(randomInt);
filePath = cursor.getString(columnIndex);
imageView.setImageBitmap(decodeSampledBitmapFromResource(filePath,width,height));
And for efficiently using bitmaps so that you do not run into OutOfMemory Exceptions here are two functions startight from the androids developers page [link http://developer.android.com/training/displaying-bitmaps/load-bitmap.html]
public Bitmap decodeSampledBitmapFromResource(String path, int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds = true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path,options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(path, options);
}
public static int calculateInSampleSize( BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee
// a final image with both dimensions larger than or equal to the
// requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}

Converting string to uri to bitmap to display in an ImageView

I have looked all over for a solution to my problem and just can't seem to figure it out. I'm sure it is probably 1 or 2 simple lines and hopefully someone can steer me in the right direction.
In my app, a user can click a button that will open the gallery. Once they select an image, it will display that image in an ImageView within my app. That part is working perfectly fine. Originally, I just had it return a uri from the gallery and I would directly display that with this:
imageView1.setImageURI(myUri);
Well, obviously I am now running into the dreaded "Out Of Memory" error if the user reloads that page several times in a row so I'm having to clean up my code to scale down the image. I have done this by implementing a bitmap class that turns the image into a bitmap and scales it down for me. Now, my ImageView display code looks like this:
imageView1.setImageBitmap(bitmap1);
That part is working fine as well. HERE IS THE PROBLEM:
I convert the uri path to a string and then save that in a SharedPreference. This is so that when the user exits the application and the comes back later, the image that they set automatically displays. I convert the uri like this:
...
selectedImageUri = data.getData();
String selectedImagePath;
selectedImagePath = getPath(selectedImageUri);
...
The old method to retrieve the SharedPreference String, convert it to uri, then display it was working fine. (except for the Out Of Memory error of course) It looked like this:
Uri myUri = Uri.parse(selectedImagePath);
imageView1 = setImageURI(myUri);
"selectedImagePath" is obviously the String that I retrieved from the SharedPreference. Again, this worked fine but would throw the error if reloaded too many times.
The part that IS NOT WORKING now is when I try to implement the new Bitmap conversion so that I can scale the bitmap and not get the memory error. Here is the code for that:
Uri myUri = Uri.parse(selectedImagePath)
Bitmap bitmap = getThumbnail(myUri);
imageView1.setImageBitmap(bitmap);
This displays nothing. The original image choosing displays the image fine but when I return to this screen and it tries to parse the string from the SharedPreference and then convert it to the bitmap, nothing ever displays. The code for the "getThumbnail" method was taken directly from THIS POST --->
How to get Bitmap from an Uri?
It is the 3rd answer down.
Anyone have any ideas? Sorry for the super long post but I'd rather over explain my problem than not give enough info. Sorry if this was answered somewhere else. I've been hunting through other questions for hours and have just not found anything that solves my problem.
Thanks.

I figured it out so here is what I did for anyone else having this unique problem. After the image is chosen from the gallery and it returns the intent, I got the data from that intent via this code:
selectedImageUri = data.getData();
Then I got the path from that via this:
selectedImagePath = getPath(selectedImageUri);
Which made a call to this "getPath" method:
public String getPath(Uri uri)
{
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
cursor.moveToFirst();
int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
return cursor.getString(idx);
}
Then I saved "selectedImagePath" as a SharedPreference string.
Later, to retrieve that string and convert it back to showing an image, I first retrieved the SharedPreference string and converted it back to "selectedImagePath". Then, I set it in the ImageView like this:
targetImage = (ImageView)findViewById(R.id.imageView1);
targgetImage.setImageBitmap(decodeSampledBitmapFromResource(selectedImagePath, 200, 200));
which made a call to the following methods:
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 2;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float)height / (float)reqHeight);
} else {
inSampleSize = Math.round((float)width / (float)reqWidth);
}
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromResource(String resId,
int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(resId, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(resId, options);
}
It's a heck of a lot of code to do a fairly simple task but it works so I'm happy and moving on. Hopefully this will help someone else who needs to accomplish the same thing.

Android - Out of Memory Exception in ScrollView

I know this must be one of the most asked things at SO, but none of the other answers gave me a solution. But from reading the other answers, looks like I'll need to redesign the way the App is working.
It's like this, we have a ScrollView, which will inflate some views. A ListView can't be used in this situation, because to behave the way we want it would require extending the ListView, and this is something we don't want to do (even though this seems to be our only solution to our current way of showing items, because of this OOM exception). The list can have a lot of columns per row, and the bigger the screen, more columns it will have.
Each inflated View has a layout displaying some info from the database, including a picture. This picture is stored through a byte array. It's any picture taken with the device camera. Currently every photo (byte array) is taking 800kb to 1mb, which seems a lot to me. Now the list have 30+ items. I took photos until the OOM happened, and it happened when I took a total of 6 photos (occasionally 7). That would be 8mb-9mb of data. Everytime I go to other Activity, and go back to the Activity the ScrollView is in, the list needs to be repopulated.
This is the snippet of the PopulateList method:
if (item.getImg() != null) {
if (App.debug) {
Log.d(TAG, "Setting bmp.");
}
Bitmap bmp = App.byteArrayToBmp(item.getImg());
imgV.setImageBitmap(bmp);
}
Every inflated View will open an 'Advanced Dialog', which will contain other info. Maybe the Image could be there instead on the list (meaning that there would be only 1 bitmap, as every inflated View shares the same advanced dialog). Or I could extend the ListView and benefit from it recycling method (It's not a good solution as I though it would be considering more than 6 items can be at the screen). Another thing that bothers me is every picture having 800kb. Seems like a lot for a 128x128.
This is the setup for the size:
cameraParams.setPictureSize(App.pxToDpi(128), App.pxToDpi(128));
cameraParams.setPictureFormat(PixelFormat.JPEG);
camera.setParameters(cameraParams);
public static int pxToDpi(int px) {
final int scale = app.getApplicationContext().getResources().getDisplayMetrics().densityDpi;
int pixels = (int) px * (scale / 160);
return pixels;
}
So, do you think there is a solution to my issue keeping the current model of my App, or will I need to reformulate?
EDIT: The bitmap method:
public static Bitmap byteArrayToBmp(byte[] byteArray) {
Bitmap img = null;
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inSampleSize = 2;
img = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length, opts);
return img;
}

You might want to look at the Official Android Training docs, they've just been updated:
Check out Displaying Bitmaps Efficiently with the lesson: Loading Large Bitmaps Efficiently that goes over this.
Basically you can decode the image using sampleSize to decode it to the width and height you want:
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float)height / (float)reqHeight);
} else {
inSampleSize = Math.round((float)width / (float)reqWidth);
}
}
return inSampleSize;
}
Explained in much great detail in the links above