I am working on an Android app, And I put many pictures in Assets directory by categories. And I get a bitmap of a image using code below
InputStream in = getAssets().open(file);
Bitmap bm = BitmapFactory.decodeStream(in);
Bitmap board = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(board);
canvas.drawBitmap(bm,0,0,null);
And the width and height(pixel) of all my image files is 360x240， I want the Bitmap:board to be 960x720 when the images are read because I need convert the bitmap to a 960x720 Mat using OpenCV.
What can I do?
You can use createScaledBitmap :
Bitmap createScaledBitmap (Bitmap src,
int dstWidth,
int dstHeight,
boolean filter)
Creates a new bitmap, scaled from an existing bitmap, when possible.
If the specified width and height are the same as the current width
and height of the source bitmap, the source bitmap is returned and no
new bitmap is created.
Related
I need to figure out a way to get a bitmap cropped without creating another bitmap that is already present.
I have two bitmaps
int width = 50;
int height = 50;
//Bitmap A
bitmapA = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
bitmapA.copyPixelsFromBuffer(buffer);
//Bitmap B
bitmapB = Bitmap.createBitmap(45, 45, Bitmap.Config.ARGB_8888);
bitmapA has an image data, while bitmapB has no image data. I need a cropped image of bitmapA starting from (5, 5) and put it into bitmapB without creating another new Bitmap.
While I can do
bitmapC = Bitmap.createBitmap(bitmapA, 5, 5, 45, 45);
this will create another Bitmap object. I need to copy the data of bitmapA into the already created bitmapB without creating another Bitmap / calling createBitmap
Can this be done by using Rect?
Any ideas? thanks.
I am trying to implement overlay transformation for Picasso library.
So, I am loading image into image view and want to display overlay using bitmpap
First of all I am fill canvas with transparent color
Then I am trying to draw drawable over
#Override
public Bitmap transform(Bitmap source){
Bitmap workingBitmap=Bitmap.createBitmap(source);
Bitmap mutableBitmap=workingBitmap.copy(Bitmap.Config.ARGB_8888,true);
Canvas canvas=new Canvas(mutableBitmap);
canvas.drawColor(getResources().getColor(R.color.gray_transparent));
BitmapFactory.Options options=new BitmapFactory.Options();
options.inScaled=false;
Bitmap b=BitmapFactory.decodeResource(getResources(),R.drawable.ic_gif_white_24dp,options);
canvas.drawBitmap(b,source.getWidth()/2,source.getHeight()/2,paint);
source.recycle();
return mutableBitmap;
}
The problem is that I see different overlay image size when canvas size is different. How I can avaid bitmap scaling depends on canvas size? I want to see same GIF size with different canvases size.
On first image canvas has w = 1280, h = 854, second image w = 480, h = 270
UPDATE
I found solution to scale bitmap depends on canvas size, it works well, but I wish to find out better solution
BitmapDrawable drawable = (BitmapDrawable) getResources().getDrawable(R.drawable.ic_gif_white_24dp);
Bitmap drawableBitmap = drawable.getBitmap();
double size = source.getWidth() * 0.15;
Bitmap scaled = Bitmap.createScaledBitmap(drawableBitmap, (int) size, (int) size, true);
I know how to crop a bitmap image from resources, but i want to cache image from ImageView to Bitmap, and then i want to crop it.
So, here is my code:
mImageViewArt.buildDrawingCache();
Bitmap bmap = mImageViewArt.getDrawingCache(); // works good
Bitmap bmp= BitmapFactory.decodeResource(getResources(),bmap); // Doesn't work(Cannot be aplied Int to Bitmap)
Bitmap resizedbitmap1 = Bitmap.createBitmap(bmp, 0, 0, 100, 100);
Why are you using the bmp intermediate variable?
If you want to crop the image returned by getDrawingCache(), you should just pass it as the input to Bitmap.createBitmap(), i.e.
mImageViewArt.buildDrawingCache();
Bitmap bmap = mImageViewArt.getDrawingCache();
Bitmap resizedbitmap1 = Bitmap.createBitmap(bmap, 0, 0, 100, 100);
I have to crop a bitmap image. For this, I am using
Bitmap bitmap = Bitmap.createBitmap(imgView.getWidth(),imgView.getHeight(), Bitmap.Config.RGB_565);
Bitmap result =Bitmap.createBitmap(bitmap,imgView.getLeft()+10, imgView.getTop()+50, imgView.getWidth()-20, imgView.getHeight()-100);
bitmap.recycle();
Canvas canvas = new Canvas(result);
imgView.draw(canvas);
But it cuts the bottom and right of the bitmap. Top and Left part of the bitmap exists in the output. That means x and y position has no effect.
I am searched for good documentation. But I couldn't.
Thanks in Advance
What is the problem here and how to solve?
Basically your problem arises form the fact that you create a bitmap. You don't put anything in it. You then create a smaller bitmap and then you render an imageView to that smaller bitmap.
This cuts off the bottom 100 pixels and right 20 pixels.
You need to Create the large bitmap. Add the imageview data to that bitmap. Then resize it.
The following code should work:
Bitmap bitmap = Bitmap.createBitmap(imgView.getWidth(),imgView.getHeight(), Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
imgView.draw(canvas);
Bitmap result =Bitmap.createBitmap(bitmap,imgView.getLeft()+10, imgView.getTop()+50, imgView.getWidth()-20, imgView.getHeight()-100);
bitmap.recycle();
I've encountered totally bizarre behavior in the way Android loads bitmaps into ImageView. For example, I have a 500x313 image file called urimg_01.jpg. With this code:
img.setImageResource(R.drawable.urimg_01);
Bitmap bitmap = ((BitmapDrawable) img.getDrawable()).getBitmap();
Log.v(TAG,"---------------------> bitmap width = "+bitmap.getWidth());
Log.v(TAG,"---------------------> bitmap height = "+bitmap.getHeight());
the ImageView bitmap is 750x470. (I have a Nexus S with 480x800 display.)
With this code, which reads a copy of the same file located in getFilesDir():
Log.v(TAG,"image file is "+filelist[0].getAbsolutePath());
FileInputStream fis = new FileInputStream(filelist[0]);
FileDescriptor fd = fis.getFD();
Bitmap bitmap = BitmapFactory.decodeFileDescriptor(fd);
if (bitmap != null) {
Log.v(TAG,"---------------------> bitmap width = "+bitmap.getWidth());
Log.v(TAG,"---------------------> bitmap height = "+bitmap.getHeight());
img.setImageBitmap(bitmap);
fis.close();
}
the ImageView bitmap is 500x313, as expected.
In the case of setImageResource(), where the devil is it getting 750x470 from?? And how do I get it to use the correct dimensions for resources in drawable?
Your resource is being scaled up because it's probably stored in a medium density folder and you're using a high density device. See Bitmap getWidth returns wrong value for details.
here you get your bitmap
Bitmap bitmap = BitmapFactory.decodeFileDescriptor(fd);
now scale it according to device height and width
Display display=this.getWindowManager().getDefaultDisplay();
int w=display.getWidth();
int h=display.getHeight();
Bitmap newBitmap=Bitmap.createScaledBitmap(oldBitmap, w, h, false);
//now setImage to background with new Bitmap
One important thing "this" should be activity context
:) cheers