Develop Reference

Memory issues on rescaling bitmap

So, I have this test project where I try to circumnavigate issues that I find with bitmaps and I'm having more issues than usual with resizing bitmaps. The project, pre-resizing tests, allowed me to load a bitmap from a stream, show it, and dispose it. In a loop.
protected override void OnCreate (Bundle bundle){
...
int i = 0;
System.Timers.Timer t = new System.Timers.Timer (100);
t.Elapsed += delegate(object sender, System.Timers.ElapsedEventArgs e) {
RunOnUiThread(delegate() {
if(i++ % 2 == 0){
Console.WriteLine("Iteration no: " + i);
tmpView tView = new tmpView(this);
mainView.AddView(tView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent));
}else{
((tmpView)mainView.GetChildAt(0)).dispose();
mainView.RemoveAllViews();
}
});
};
t.AutoReset = true;
t.Start ();
}
and the tmpView code:
private class tmpView:RelativeLayout{
PTImage img;
ImageView img2;
PTImageObj imgObj;
Android.Graphics.Bitmap bmp;
Bitmap resized;
public tmpView(Context cntx):base(cntx){
SetBackgroundColor(new Android.Graphics.Color(200, 0, 0, 200));
System.IO.Stream imgStream = Application.Context.Assets.Open ("backgroundLeft.png");
bmp = Android.Graphics.BitmapFactory.DecodeStream (imgStream, new Android.Graphics.Rect(), new Android.Graphics.BitmapFactory.Options(){InPurgeable = true, InInputShareable = true});
img2 = new ImageView(cntx);
img2.SetImageBitmap(bmp);
imgStream.Close();
imgStream.Dispose();
GC.SuppressFinalize(imgStream);
imgStream = null;
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MatchParent, 500);
lp.TopMargin = 150;
this.AddView(img2, lp);
}
public void dispose(){
bmp.Recycle ();
img2.SetImageDrawable (null);
}
}
So far that works fine, I can leave it iterating for as long as I want without having outOfMemory issues. However, if I want to change the tmpView code to this:
public tmpView(Context cntx):base(cntx){
SetBackgroundColor(new Android.Graphics.Color(200, 0, 0, 200));
System.IO.Stream imgStream = Application.Context.Assets.Open ("backgroundLeft.png");
bmp = Android.Graphics.BitmapFactory.DecodeStream (imgStream, new Android.Graphics.Rect(), new Android.Graphics.BitmapFactory.Options(){InPurgeable = true, InInputShareable = true});
resized = Bitmap.CreateScaledBitmap(bmp, bmp.Width + 50, bmp.Height + 50, false);
bmp.Recycle();
img2 = new ImageView(cntx);
img2.SetImageBitmap(resized);
imgStream.Close();
imgStream.Dispose();
GC.SuppressFinalize(imgStream);
imgStream = null;
}
I end up with outOfMemory issues at about ~200 iterations. My guess is that the rescaling is creating temp bitmaps that I can't force recycle. Is there a better way of resizing the bitmap so I can continue the loop without crashing?
Note: if I don't actually resize, if I give the CreateScaledBitmap the same sizes the bitmap has, I don't run into the memory issues. But... that kind of defeats the purpose :P. Oh, and yes, I did add the resized.Recycle (); in the dispose
Note2: The code is in C# but I'm fine with answers in java
Thank you,
Axel

Restoring the image from Native Memory using NDK returns Black Image with No display

I am trying to restore the image from Native memory (using NDK,C/C++) but that returns me an Black Image.
What i am doing ::
1)get the image from Drawable
2)apply the rotation to the image
3)After rotation apply the grayscale effect to the image
4)At the end i am trying to save the grayscale image in SD Card
For all the above steps, i am referring this awesome lib,which have the native method to store and restore the images.
Please note image is being stored in the SD card but when i am trying to see the image,its totally black with no display at all.
My Java Implementation ::
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.item_rotate_90:
options.inPreferredConfig = Config.ARGB_8888;
bitmapOrig = BitmapFactory.decodeResource(this.getResources(), R.drawable.sample_cam,options);
storeBitmap(bitmapOrig);
bitmapOrig.recycle();
rotateBitmap(90,_handler);
tempBmp=getBitmapAndFree();
bitmapWip = Bitmap.createBitmap(bitmapOrig.getWidth(),bitmapOrig.getHeight(),Config.ALPHA_8);
jniConvertToGray(tempBmp,bitmapWip);
if(bitmapWip!=null)
{
try
{
Bitmap b = Bitmap.createBitmap(bitmapWip.getWidth(),bitmapWip.getHeight(),Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bitmapWip, 0, 0, paint);
storeBitmap(b);
SaveGrayScaledImage(b);
b.recycle();
tempBmp.recycle();
} catch (IOException e) {
e.printStackTrace();
}
ivDisplay.setImageBitmap(bitmapWip);
}
break;
}
}
I have not make any changes in native method(means using the same method as this lib have for storing and restoring the image).
Saving image to SD Card ::
private void SaveGrayScaledImage(Bitmap finalBitmap)throws IOException
{
String imageFileName = "Temp" + "_gray";
File albumF = new File("/mnt/sdcard/","gray_img");
if(!albumF.exists())
{
albumF.mkdirs();
}
// File imageF = File.createTempFile(imageFileName, JPEG_FILE_SUFFIX,
// albumF);
File imageF = new File(albumF,imageFileName + ".jpeg");
if (imageF.exists()) {
imageF.delete();
imageF.createNewFile();
}
try {
FileOutputStream out = new FileOutputStream(imageF);
finalBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
imageF = null;
}
}
While googling, i found that(may be i am wrong) image which returns for Native Memory have the ALPHA_8 bitmap config,so i convert the config ALPHA_8 t0 ARGB_8888,but the result is same.
Conversion of bitmap from ALPHA_8 to ARGB_8888 ::
Bitmap b = Bitmap.createBitmap(bitmapWip.getWidth(),bitmapWip.getHeight(),Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bitmapWip, 0, 0, paint);
StoreBimap funcation ::
public void storeBitmap(final Bitmap bitmap)
{
if(_handler!=null)
freeBitmap();
_handler=jniStoreBitmapData(bitmap);
}
I have no clue about where i was wrong. i have checked the lib methods and implmentation again and again to find the issue.
I have spent my many hours on this small issue and it really frustrating me.
Let me know please if you need anything else from my side.
Please help me to resolve this issue.
Many Thanks in Advance....
EDIT ::
bitmapHolder=new JniBitmapHolder();
final Options options=new Options();
BitmapFactory.decodeFile(picPath, options);
options.inJustDecodeBounds=true;
options.inPreferredConfig=Config.ARGB_8888;
prepareForDownsampling(options,192,256);
System.gc();
bmpGrayscale=BitmapFactory.decodeFile(picPath,options);
int width = bmpGrayscale.getWidth();
int height = bmpGrayscale.getHeight();
bitmapHolder.storeBitmap(bmpGrayscale);
bmpGrayscale.recycle();
Bitmap thumbnail = null;
int rotationInDegrees = 0;
if (picPath != null) {
Uri uri = Uri.parse(picPath);
ExifInterface exif = null;
try {
exif = new ExifInterface(uri.getPath());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int rotation = exif.getAttributeInt(
ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL);
rotationInDegrees = exifToDegrees(rotation);
}
rotationInDegrees = 90;
ByteBuffer _handler =null;
switch(rotationInDegrees)
{
case 90:
bitmapHolder.rotateBitmapCw90();
break;
case 180:
bitmapHolder.rotateBitmap180();
break;
}
Bitmap bitmapWip = Bitmap.createBitmap(width,height,Config.ALPHA_8);
bitmapHolder.bitmapGrayScale(bitmapWip);
if(bitmapWip!=null){
File CurrentFile = saveGrayScaledIamge(bitmapWip,
takePhotoFile);
}
I have followed your suggestion/steps but the result is same,getting black image with no display.

ok I've found multiple problems and tips for improvements:
the first createBitmap is run with width*height on a bitmap that got rotated instead of height*width. this should be as:
rotateBitmap(90,_handler);
tempBmp=getBitmapAndFree();
bitmapWip=Bitmap.createBitmap(bitmapOrig.getHeight(),bitmapOrig.getWidth(),Config.ALPHA_8);
when saving file you don't get the correct path (you use a hardcoded path, and Lint warns about it).
jniConvertToGray doesn't really need to go over arrays and can just use a pointer, as it just runs on a single pixel. you store the bitmap into JNI twice instead of once (just do: store, rotate, grayscale, restore&free).
you don't use the new bitmap after you have finished working on it, so if I call rotation multiple times, it doesn't seem to do anything.
you already have bitmapWip rotated and grayscaled. why do you need to make a new bitmap that has its content in it, do a grayscale on it, and then save it ?
functions should be named with lowercase letter in the beginning of their names.
and finally , the most important thing: you use ALPHA_8 for the image that you show and need to save to file. this configuration has no color. it's a mask. In order to see the problem, you should set a background color to the imageView :
ivDisplay.setBackgroundColor(0xFFff0000);
before choosing the rotation, you see nothing red. after choosing it, everything you think is white, has actually become red. that's because it's transparent...
If in any phase of your development you've succeeded saving the image to a file and thought it's a black image (yet the size is not 0) , try to edit it and put a background behind it. Maybe you got lucky and just got transparent pixels...
Adding the fact that you save the file to a jpg format, which doesn't support transparency, might also contribute to unexpected behaviors.
in order to solve this, you should use the same technique i've used - use a single bitmap all the time. no need to create so many. only one should exist on the java world, and it should support having colors.

Programmatic Image Resizing in Android, Memory Issues

Days, I've spent working on this. Weeks, perhaps. Literally. :(
So I've got an image on an SD card that more than likely came out of the built-in camera. I want to take that image and downsample it to an arbitrary size (but always smaller and never larger). My code uses standard Android Bitmap methods to decode, resize, recompress, and save the image. Everything works fine as long as the final image is smaller than 3MP or so. If the image is larger, or if I try to do several of these at once, the application crashes with an OutOfMemoryError. I know why that's happening, and I know it's happening for a perfectly legitimate reason, I just want it to not happen anymore.
Look, I'm not trying to launch a rocket here. All I want to do is resize a camera image and dump it to an OutputStream or even a temporary file. Surely someone out there must have done such a thing. I don't need you to write my code for me, and I don't need my hand held. But between my various programming abortions and days of obsessed Googling, I don't even know which direction to head in. Roughly speaking, does anyone know how to decode a JPEG, downsample it, re-compress it in JPEG, and send it out on an OutputStream without allocating a massive amount of memory?

Ok I know it's a little bit late but, I had this problem and I found solution. It is actually easy and I am sure it supports back to api 10(I have no idea about before 10). I tried this with my phone. It is a samsung galaxy s2 with an 8mp camera and the code perfectly resized camera images to the 168x168 as well as images i found on web. I checked the images by using file manager too. I never tried resizing images to bigger resoulation.
private Bitmap resize(Bitmap bp, int witdh, int height){
return Bitmap.createScaledBitmap(bp, width, height, false);
}
you can save it like this
private void saveBitmap(Bitmap bp) throws FileNotFoundException{
String state = Environment.getExternalStorageState();
File folder;
//if there is memory card available code choose that
if (Environment.MEDIA_MOUNTED.equals(state)) {
folder=Environment.getExternalStorageDirectory();
}else{
folder=Environment.getDataDirectory();
}
folder=new File(folder, "/aaaa");
if(!folder.exists()){
folder.mkdir();
}
File file=new File(folder, (int)(Math.random()*10000)+".jpg");
FileOutputStream os=new FileOutputStream(file);
bp.compress(Bitmap.CompressFormat.JPEG, 90, os);
}
thanks to this link

The following code is from my previous project. Key point is "options.inSampleSize".
public static Bitmap makeBitmap(String fn, int minSideLength, int maxNumOfPixels) {
BitmapFactory.Options options;
try {
options = new BitmapFactory.Options();
options.inPurgeable = true;
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(fn, options);
if (options.mCancel || options.outWidth == -1
|| options.outHeight == -1) {
return null;
}
options.inSampleSize = computeSampleSize(
options, minSideLength, maxNumOfPixels);
options.inJustDecodeBounds = false;
//Log.e(LOG_TAG, "sample size=" + options.inSampleSize);
options.inDither = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
return BitmapFactory.decodeFile(fn, options);
} catch (OutOfMemoryError ex) {
Log.e(LOG_TAG, "Got oom exception ", ex);
return null;
}
}
private static int computeInitialSampleSize(BitmapFactory.Options options,
int minSideLength, int maxNumOfPixels) {
double w = options.outWidth;
double h = options.outHeight;
int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1 :
(int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
int upperBound = (minSideLength == UNCONSTRAINED) ? 128 :
(int) Math.min(Math.floor(w / minSideLength),
Math.floor(h / minSideLength));
if (upperBound < lowerBound) {
// return the larger one when there is no overlapping zone.
return lowerBound;
}
if ((maxNumOfPixels == UNCONSTRAINED) &&
(minSideLength == UNCONSTRAINED)) {
return 1;
} else if (minSideLength == UNCONSTRAINED) {
return lowerBound;
} else {
return upperBound;
}
}

Loading multiple high quality bitmaps and scaling them

I've got a serious performance issue in my app, when loading up bitmaps it seems to take up way to much memory.
I have a drawable folder which contains the bitmap sizes for all android devices, these bitmaps are of high quality. Basically it goes though each bitmap and makes a new one for the device depending on the size. (Decided to do it this way because it supports the correct orientation and any device). It works but it's taking up way to much memory and takes along time to load. Can anyone make any suggestions on the following code.
public Bitmap getBitmapSized(String name, int percentage, int screen_dimention, int frames, int rows, Object params)
{
if(name != "null")
{
_tempInt = _context.getResources().getIdentifier(name, "drawable", _context.getPackageName());
_tempBitmap = (BitmapFactory.decodeResource(_context.getResources(), _tempInt, _BM_options_temp));
}
else
{
_tempBitmap = (Bitmap) params;
}
_bmWidth = _tempBitmap.getWidth() / frames;
_bmHeight = _tempBitmap.getHeight() / rows;
_newWidth = (screen_dimention / 100.0f) * percentage;
_newHeight = (_newWidth / _bmWidth) * _bmHeight;
//Round up to closet factor of total frames (Stops juddering within animation)
_newWidth = _newWidth * frames;
//Output the created item
/*
Log.w(name, "Item");
Log.w(Integer.toString((int)_newWidth), "new width");
Log.w(Integer.toString((int)_newHeight), "new height");
*/
//Create new item and recycle bitmap
Bitmap newBitmap = Bitmap.createScaledBitmap(_tempBitmap, (int)_newWidth, (int)_newHeight, false);
_tempBitmap.recycle();
return newBitmap;
}

There's an excellent guide over on the Android Training site:
http://developer.android.com/training/displaying-bitmaps/load-bitmap.html
It's about efficient loading of bitmap images - highly recommended!

This will save space. If not using Alpha colors it would be better not to use one with the A channel.
Options options = new BitmapFactory.Options();
options.inScaled = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
// or Bitmap.Config.RGB_565 ;
// or Bitmap.Config.ARGB_4444 ;
Bitmap newBitmap = Bitmap.createScaledBitmap(_tempBitmap, (int)_newWidth, (int)_newHeight, options);

combining two png files in android

I have two png image files that I would like my android app to combine programmatically into one png image file and am wondering if it is possible to do so? if so, what I would like to do is just overlay them on each other to create one file.
the idea behind this is that I have a handful of png files, some with a portion of the image on the left with the rest transparent and the others with an image on the right and the rest transparent. and based on user input it will combine the two to make one file to display. (and i cant just display the two images side by side, they need to be one file)
is this possible to do programmatically in android and how so?

I've been trying to figure this out for a little while now.
Here's (essentially) the code I used to make it work.
// Get your images from their files
Bitmap bottomImage = BitmapFactory.decodeFile("myFirstPNG.png");
Bitmap topImage = BitmapFactory.decodeFile("myOtherPNG.png");
// As described by Steve Pomeroy in a previous comment,
// use the canvas to combine them.
// Start with the first in the constructor..
Canvas comboImage = new Canvas(bottomImage);
// Then draw the second on top of that
comboImage.drawBitmap(topImage, 0f, 0f, null);
// comboImage is now a composite of the two.
// To write the file out to the SDCard:
OutputStream os = null;
try {
os = new FileOutputStream("/sdcard/DCIM/Camera/" + "myNewFileName.png");
comboImage.compress(CompressFormat.PNG, 50, os)
} catch(IOException e) {
e.printStackTrace();
}
EDIT :
there was a typo,
So, I've changed
image.compress(CompressFormat.PNG, 50, os)
to
bottomImage.compress(CompressFormat.PNG, 50, os)

You can do blending. This is not particular to Android. It's just universal image processing.
EDIT:
You may find these articles & samples & code useful:
http://www.jhlabs.com/ip/
http://kfb-android.blogspot.com/2009/04/image-processing-in-android.html
http://code.google.com/p/jjil/
Image Processing on Android

I use this code
private class PhotoComposition extends AsyncTask<Object, Void, Boolean> {
private String pathSave;//path save combined images
#Override
protected Boolean doInBackground(Object... objects) {
List<String> images = (List<String>) objects[0]; //lsit of path iamges
pathSave = (String) objects[1];//path save combined images
if (images.size() == 0) {
return false;
}
List<Bitmap> bitmaps = new ArrayList<>();
for (int i = 0; i < images.size(); i++) {
bitmaps.add(BitmapFactory.decodeFile( images.get(i)));
}
int width = findWidth(bitmaps);//Find the width of the composite image
int height = findMaxHeight(bitmaps);//Find the height of the composite image
Bitmap combineBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);//create bitmap of composite image
combineBitmap.eraseColor(Color.parseColor("#00000000")); //bcakgraound color of composite image
Bitmap mutableCombineBitmap = combineBitmap.copy(Bitmap.Config.ARGB_8888, true);//create mutable bitmap to create canvas
Canvas canvas = new Canvas(mutableCombineBitmap);// create canvas to add bitmaps
float left = 0f;
for (int i = 0; i < bitmaps.size(); i++) {
canvas.drawBitmap(bitmaps.get(i), left, 0f, null);//Taking photos horizontally
left += bitmaps.get(i).getWidth();//Take right to the size of the previous photo
}
OutputStream outputStream = null;
try {
outputStream = new FileOutputStream(pathSave);//path of save composite image
mutableCombineBitmap.compress(Bitmap.CompressFormat.PNG, 80, outputStream);
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
#Override
protected void onPostExecute(Boolean isSave) {
if (isSave) {
//iamge save on pathSave
Log.i("PhotoComposition", "onPostExecute: " + pathSave);
}
super.onPostExecute(isSave);
}
private int findMaxHeight(List<Bitmap> bitmaps) {
int maxHeight = Integer.MIN_VALUE;
for (int i = 0; i < bitmaps.size(); i++) {
if (bitmaps.get(i).getHeight() > maxHeight) {
maxHeight = bitmaps.get(i).getHeight();
}
}
return maxHeight;
}
private int findWidth(List<Bitmap> bitmaps) {
int width = 0;
for (int i = 0; i < bitmaps.size(); i++) {
width += bitmaps.get(i).getWidth();
}
return width;
}
USAGE
List<String> images = new ArrayList<>();
images.add("/storage/emulated/0/imageOne.png");//path of image in storage
images.add("/storage/emulated/0/imageTwo.png");
// images.add("/storage/emulated/0/imageThree");
// ... //add more images
String pathSaveCombinedImage = "/storage/emulated/0/CombinedImage.png";//path save result image
new PhotoComposition().execute(images, pathSaveCombinedImage);
And the result of using the above code will be as follows

You may wish to look into the Canvas object, which would make it easy to do other drawing operations as well. You can just draw your bitmaps onto a canvas where you want them, then save the resulting bitmap.

If they have transparent sections, then if you draw one on top of the other, only the non-transparent portions will overlap. It will be up to you to arrange the bitmaps however you like.
For the separate issue of re-saving your image to a png, use bitmap.compress().

Try this .
public Bitmap mergeBitmap(Bitmap frame, Bitmap img){
Bitmap bmOverlay = Bitmap.createBitmap(frame.getWidth(), frame.getHeight(), frame.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(img, 0, 0, null);
canvas.drawBitmap(frame, new Matrix(), null);
return bmOverlay;
}
Returns a bitmap image
Pass two bitmap images to your function as shown below
Bitmap img= mergeBitmap(imgone, imagetwo);
See the entire post or also see merge multiple images in android programmatically