Develop Reference

Modify a PNG image in the drawable folder

I have a PNG file in my drawable folder.
I need to modify it merging on it a smaller image.
I use this code for create a new Bitmap
Bitmap bigImage = BitmapFactory.decodeResource(getResources(), R.drawable.i10);
Bitmap smallImage = BitmapFactory.decodeResource(getResources(), R.drawable.i11);
Bitmap result = Bitmap.createBitmap(bigImage.getWidth(), bigImage.getHeight(), bigImage.getConfig());
Canvas canvas = new Canvas(result);
canvas.drawBitmap(bigImage, 0f, 0f, null);
canvas.drawBitmap(smallImage, 10, 10, null);
That I miss is the final part. Assign the new bitmap (bigImage) to "R.drawable.i10"

Resources are static, you cannot change those files once they are shipped in the app (Apk)...
However you can create/manipulate the existing ones & save it as a new file on Storage but that's a different thing & not related with the question!

How to save an image in sdcard after applying RGB color filter in android

Presently I am designing an application based on photo editing. While doing this i encountered with a problem i.e.
I have gone through a tutorial "how to apply RGB color filter for an image" from this link and this tutorial is very helpful and nice.
But the problem is after applying RGB color filter to the image i need to save the changed image in sd card.
I have googled a lot for this but didn't found exact thing.
Many of them sugested to use paint() But im not getting how to use that.
So exactly my problem is "After Applying RBG Coloration to image I need to save that image in SD Card, But I do not found the how to do it" ?

How to Save an Android ImageView to SD Card
You have an ImageView which you've modified via various lighting effects and color filters and now you wish to save the result to the SD card as as a .jpg or .png format image.
Here's how:
Load Bitmap image from View.
Save Bitmap image to SD card.
Example:
Don't forget to test for Exceptions and add the necessary permissions to your manifest!
ImageView imageView = <View to save to SD card>;
Bitmap bitmap = loadBitmapFromView(imageView);
final String pathTxt = Environment.getExternalStorageDirectory();
File storagePath = new File(pathTxt);
File file = new File(storagePath, "filename.jpg");
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);
out.flush();
out.close();
private Bitmap loadBitmapFromView(View v) {
final int w = v.getWidth();
final int h = v.getHeight();
final Bitmap b = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
final Canvas c = new Canvas(b);
//v.layout(0, 0, w, h);
v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
v.draw(c);
return b;
}

Theree are two methods for this...
1.after applying RGB values save those values in a variables and apply that values to the image selected.
2.after applying RGB values take the image from image view and save it

Setting a bitmap using RemoteView not working

Im writing a widget and I need to download and set a bitmap on the layout. Everything I've tried doesn't seem to work.
I've created a test bitmap now to set on the view, [update] this works.
Bitmap.Config config = Bitmap.Config.ARGB_8888;
Bitmap bitmap = Bitmap.createBitmap(imageActiveWidth, imageHeight, config);
Canvas canvas = new Canvas(bitmap); // Load the Bitmap to the Canvas
Paint paint = new Paint();
paint.setColor(0xFFFFCCFF);
canvas.drawRect(0, 0, imageActiveWidth, imageHeight, paint);
views.setImageViewBitmap(resId, bitmap);
using a resource file does work:
Bitmap placeholderBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.placeholder_medium);
views.setImageViewBitmap(imageSlotId, placeholderBitmap);
However using a downloaded bitmap does not seem work.
(after async task has downloaded bitmap, I have a method setBitmap which is one line:
views.setImageViewBitmap(resId, proxy);
Result - screen is just white, no bitmap
I'm really stumped on how to get this to work, because I need to be able to download bitmaps and set them.

Found a solution. I think its related to this bug:
http://code.google.com/p/android/issues/detail?id=8489
Solved by changing by setBitmap method to the following:
private void setBitmap(RemoteViews views, int resId, Bitmap bitmap){
Bitmap proxy = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(proxy);
c.drawBitmap(bitmap, new Matrix(), null);
views.setImageViewBitmap(resId, proxy);
}
And I needed to call:
AppWidgetManager.getInstance(context).updateAppWidget(appWidgetId, views);
AFTER the bitmaps had been set.
For some reason this wasn't working when I came back to it. My view was an AdapterViewFlipper, so i used the above method with a call to widgetManager.notifyAppWidgetViewDataChanged(appWidgetId, R.id.content); which caused the bitmaps to render.

Android merge two images

I want to merge two images and then save them on the Android SDCard.One is from the camera and one from the resources folder. The problem is that i get this error: Caused by: java.lang.IllegalStateException: Immutable bitmap passed to Canvas constructor. Thanks.
Bitmap bottomImage = BitmapFactory.decodeResource(getResources(),R.drawable.blink);
Bitmap topImage = (Bitmap) data.getExtras().get("data");
// 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);
// bottomImage 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");
bottomImage.compress(CompressFormat.PNG, 50, os);
//Bitmap image.compress(CompressFormat.PNG, 50, os);
} catch(IOException e) {
Log.v("error saving","error saving");
e.printStackTrace();
}
Managed to fix it by simply doing this change:
int w = bottomImage.getWidth();
int h = bottomImage.getHeight();
Bitmap new_image = Bitmap.createBitmap(w, h ,bottomImage.getConfig());
The problem now is that it doesn't saves the image. Do you know why?

This will help you =)
Edit: (embed answer from link)
the only static "constructor" for Bitmap returning a mutable one is:
(Class: Bitmap) public static Bitmap createBitmap(int width, int
height, boolean hasAlpha)
Returns: a mutable bitmap with the specified width and height.
So you could work with getPixels/setPixels or like this:
Bitmap bitmapResult = bm.createBitmap(widthOfOld, heightOfOld, hasAlpha);
Canvas c = new Canvas();
c.setDevice(bitmapResult); // drawXY will result on that Bitmap
c.drawBitmap(bitmapOld, left, top, paint);
how to get the drawable from Bitmap: by using the BitmapDrawable-Subclass which extends Drawable, like this:
Bitmap myBitmap = BitmapFactory.decode(path);
Drawable bd = new BitmapDrawable(myBitmap);

The bitmap you are retrieving is immutable, meaning it can't be modified. Although it doesn't specify on the Canvas page that the constructor needs a mutable bitmap, it does.
To create a mutable bitmap, you can use this method.

error with setPixels

i am trying to edit images. but i am getting errors with setPixels.
picw = pic.getWidth();
pich = pic.getHeight();
picsize = picw*pich;
int[] pix = new int [picsize];
pic.getPixels(pix, 0, picw, 0, 0, picw, pich);
pic.setPixels(pix,0,pic.getWidth(),0,0,pic.getWidth(),pic.getHeight());
but i am getting illegal state exception with setPixels
Caused by: java.lang.IllegalStateException
at android.graphics.Bitmap.setPixels(Bitmap.java:878)
at com.sandyapps.testapp.testapp.onCreate(testapp.java:66)

I think your Bitmap is not mutable (see setPixel()'s documentation).
If so, create a mutable copy of this Bitmap (using Bitmap.copy(Bitmap.Config config, boolean isMutable) as an example) and work on this one.

It's simple, just use the following command to change it to a mutable Bitmap:
myBitmap = myBitmap.copy( Bitmap.Config.ARGB_8888 , true);
Now the Bitmap myBitmap is replaced by the same Bitmap but this time is mutable
You can also choose another way of storing Pixels (ARGB_8888 etc..):
https://developer.android.com/reference/android/graphics/Bitmap.Config.html

Most probably your pic is immutable. By default, any bitmap created from drawable would be immutable.
If you need to modify an existing bitmap, you should do following:
// Create a bitmap of the same size
Bitmap newBmp = Bitmap.createBitmap(pic.getWidth(), pic.getHeight(), Config.ARGB);
// Create a canvas for new bitmap
Canvas c = new Canvas(newBmp);
// Draw your old bitmap on it.
c.drawBitmap(pic, 0, 0, new Paint());

I had the same problem. Use to fix it:
BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inMutable = true;
Bitmap bitmap = BitmapFactory.decodeResource( getResources(), R.drawable.my_bitmap, opt );

I was facing this problem and finally fixed after long time.
public static void filterApply(Filter filter){
Bitmap bitmcopy = PhotoModel.getInstance().getPhotoCopyBitmap();
//custom scalling is important to apply filter otherwise it will not apply on image
Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmcopy, bitmcopy.getWidth()-1, bitmcopy.getHeight()-1, false);
filter.processFilter(scaledBitmap);
filterImage.setImageBitmap(scaledBitmap);
}