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);
Related
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.
I need to create a canvas element with exact pixel size (500x500). How do I set width/height in px?
Might not be applicable in your case, but this works for me
Bitmap animation = BitmapFactory.decodeResource(mContext.getResources(), resourceId, mBitmapOptions); //Get a bitmap from a image file
// Create a bitmap for the part of the screen that needs updating.
Bitmap bitmap = Bitmap.createBitmap(animation.getWidth(), animation.getHeight(), BITMAP_CONFIG);
bitmap.setDensity(DisplayMetrics.DENSITY_DEFAULT);
Canvas canvas = new Canvas(bitmap);
You have create bitmap of the size which you want. and then Canvas canvas = new Canvas(bitmap);
This sets the canvas to the size of the bitmap
just like view.height = 100, so this view's height is 100 in px unit
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 have created a bitmap image which is a circle and than as I wanted to animate it so i converted it into bitmapdrawable and than added it to animation drawable..But due to this the circle shaped has changed to oval shape...
So what should I do ?
Is there any other method to animate only the bitmap file. ?
Thanks in advance..
If you're using Canvas, I'd suggest holding a pointer to the current Bitmap and loading all other Bitmaps into an array.
Say,
Bitmap[] frames = new Bitmap[10] //10 frames
Bitmap frame[0] = BitmapFactory.decodeResource(getResources(), R.drawable.circlefram1);
Bitmap frame[1] = BitmapFactory.decodeResource(getResources(), R.drawable.circlefram2);
...
Select the currentFrame by pointing at the frame you're interested in.
Bitmap currentBitmap = frame[3]; // 4th frame
So when you call drawBitmap(currentBitmap) it will only draw the frame you are interested in. You can change the bitmap every so many frames, by assigning an fps to the frame animation.
If you just want to scale or rotate the bitmap (rotating a circle?), the best way to resize a bitmap is using createScaledBitmap, and rotating using a matrix.
For Scaling, you load any bitmap into memory like this
Bitmap circleBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.circle);
If you would like the circle (or any bitmap) rescaled you would do something like this:
Bitmap scaledCircle = Bitmap.createScaledBitmap(circleBitmap, dstWidth, dstHeight, filter);
Where dstWidth and dstHeight are the target destination width and height, which you can previously calculate by scaling the original width and height.
int scaledHeight = circleBitmap.getHeight()/2;
int scaledWidth = circleBitmap.getWidth()/2;
And finally you would normally draw this Bitmap using a canvas like this
canvas.drawBitmap(bitmap)
For rotating, create a Matrix
Matrix mat;
mat.postRotate(degrees); // Rotate the matrix
Bitmap rotatedBitmap = Bitmap.createBitmap(originalBitmap, x, y, width, height, mat, filter);
and finally
canvas.drawBitmap(rotatedBitmap);
Keep in mind Canvases are slow for games or anything real-time!
Hope it helps.
no, you can not animate the bitmap itself with the android animation framwork. You can directly animate Views or ViewGroups and all the classes that derives from View and ViewGroup.
Call view the ImageView that contains the bitmap.
TranslateAnimation slide = new TranslateAnimation(view.getX(), view.getX() + 100, view.getY(), view.getY() + 100 );
slide.setDuration(1000);
view.startAnimation(slide)
that should translate the ImageView by 100px from the current position
I have a Bitmap image in my ressources.
When i draw it using an ImageView, it doesn't have the same size as when I draw it on the canvas using Drawbitmap.
No matter what density I use to my bitmap ( 160, 240 ), the bitmap is always zoomed.
How to draw the bitmap so it has the same size as when I use an imageview ?
The trick is to create a scaled bitmap and then draw.
my_bitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.my_bitmap);
my_bitmap = Bitmap.createScaledBitmap(my_bitmap, screenWidth, screenHeight, true);