Develop Reference

Set android bitmap size keeping aspect ratio based on minimum height and width

I'm currently loading an image that can be either landscape or portrait.
I'm then wanting to resize the bitmap to draw directly onto a canvas for a full screen image.
I need keep the aspect ratio but have the image not fit to the screen but crop off any image that's bigger than the screen.
I can resize it and fit it to the screen with the following:
Matrix m = new Matrix();
m.setRectToRect(new RectF(0, 0, b.getWidth(), b.getHeight()), new RectF(0, 0, MyWallpaperService.this.width, MyWallpaperService.this.height), Matrix.ScaleToFit.CENTER);
b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), m, true);
but I don't want to have the black bars at the top/bottom or sides, but I can't think of the routine to resize correctly for this.

As you are drawing the image onto the canvas yourself the first step is to calculate the dimensions required for the final image based on the screen size and the original image aspect ratio.
Then use the static function createScaledBitmap from the Bitmap class to resize your bitmap to match the calculated dimensions. Make sure you only call this function once and store the bitmap for use in the drawing routine.
Finally draw the bitmap so only the area of the bitmap you want to see is on the screen.
A more memory friendly approach is to add another step to crop the image using Bitmap.createBitmap before calling Bitmap.createScaledBitmap. This reduces the chance of encountering memory issues caused by the user selecting a source image that is thin and long.

How to screen shot a ImageView without lost quality

I have two ImageView's in a RelativeLayout, the first one is as large as the RelativeLayout size (as background),and the second ImageView has a small image, now I want to combine these to ImageView's image into one by screenshot. not by combine two bitmap directly.
In the snippet below, I successfully take screenshot of the RelativeLayout, but I found the image quality is not as good as the first ImageView's bitmap, can anyone help me please?
view.setDrawingCacheEnabled(true);
view.setDrawingCacheBackgroundColor(Color.TRANSPARENT);
view.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
Bitmap drawCache = view.getDrawingCache(true);

Try to get bitmap using window DecorView :
View window = activity.getWindow().getDecorView()
Canvas bitmapCanvas = new Canvas();
Bitmap bitmap = Bitmap.createBitmap(window.getWidth()*2, window.getHeight()*2, Bitmap.Config.ARGB_8888);
bitmapCanvas.setBitmap(bitmap);
bitmapCanvas.scale(2.0f, 2.0f);
window.draw(bitmapCanvas);
bitmap.compress(Bitmap.CompressFormat.PNG, 0, myOutputStream);
Ref : High resolution screen shot in Android

Set Picture into RemoteViews

I have some SVGs in my assets folder and I need to dynamically set them in my widget (on an ImageView).
I am using this library: http://code.google.com/p/svg-android/
This library returns a Picture or a PictureDrawable.
The only methods I can see to use on RemoteViews are setImageViewBitmap which obviously takes a bitmap.
I tried looking for code to convert a Drawable to a Bitmap like this:
PictureDrawable pictureDrawable = svg.createPictureDrawable();
Bitmap bitmap = Bitmap.createBitmap(pictureDrawable.getIntrinsicWidth(), pictureDrawable.getIntrinsicHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
canvas.drawPicture(pictureDrawable.getPicture());
currentBitmap = bitmap;
But the bitmap is too small. When I create the bitmap in Illustrator I set the artboard size to 65 which is what comes through on the intrinsic width/height.
My widgets can be resized so the ImageView sizes are variable. Even if I set the width and height statically to some large number like this...
Bitmap bitmap = Bitmap.createBitmap(300, 300, Config.ARGB_8888);
then the resulting bitmap just has a bunch of whitespace below and to the right of a tiny image.
I guess I need to somehow draw the picture at a scaled up value as well as creating the Bitmap at size 300. Ideally I could figure out the size of the ImageView at runtime and set the proper sized Bitmap if I knew that. Is this the best approach and how would I do this? Perhaps there is a better approach I don't even know about?

I've not used android-svg but if it's using vanilla PictureDrawables, then it should be just a matter of not using the intrinsic bounds.
Try the following:
PictureDrawable pictureDrawable = svg.createPictureDrawable();
Bitmap bitmap = Bitmap.createBitmap(300, 300, Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
pictureDrawable.setBounds(0, 0, bitmap.getWidth(), bitmap.getHeight());
pictureDrawable.draw(canvas); // do not access the Picture directly, that defeats the purpose
currentBitmap = bitmap;
In short, use the Drawable, not its Picture and set the Drawable's bounds to be the full canvas.

Have you tried createScaledBitmap?
createScaledBitmap()

I have tried svg-android and it has not worked for me for this very reason. Not to mention its severely limited feature set.
The point of using vector graphics is that I can generate images of any appropriate size to fit the UI View size. Which means the generation method must accept the size requirements at run-time, and not always use width,height declared in <svg> tag.
Hence I used the native implementation: libsvg-android, which exactly does that.
It directly renders to a canvas with given size:
long objId = SvgRaster.svgAndroidCreate();
SvgRaster.svgAndroidParseBuffer(objId, readString(mInputStream, "UTF-8"));
SvgRaster.svgAndroidSetAntialiasing(objId, true);
SvgRaster.svgAndroidRenderToArea(objId, mCanvas, 0, 0, mWidth, mHeight);

I ended up modifying the underlying Artboard size to be 300. None of the scaling up methods worked. So the final code I used was that which I originally posted:
PictureDrawable pictureDrawable = svg.createPictureDrawable();
Bitmap bitmap = Bitmap.createBitmap(pictureDrawable.getIntrinsicWidth(), pictureDrawable.getIntrinsicHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
canvas.drawPicture(pictureDrawable.getPicture());
currentBitmap = bitmap;
Once I had a 300x300 Bitmap I was able to set it into the RemoteViews using setImageViewBitmap .
This kind of defeated the purpose of using SVGs in the first place (at least as far as using them in widgets was concerned).
My problem was not the same as User117. Perhaps he did not name the outer layer 'bounds' as was required in the library. Either way, I managed to get the library working, albeit by having to modify the SVG Artboard size.
Hopefully with the increase in screen resolution Android will introduce SVGs as part of the platform soon.

Crop particular part of image in android

I want to crop Red part from following image, Is there any simple method available in android that can crop following image.
I have found many SO questions but all are suggesting to used following code:
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100);
This code work well if width & height are around 2MP resolution, but if that cropped part is more than 3MP resolution than application got crashed with OOM error.
Is there any way that handle image more than 3MP during cropping?

You can used following code that can solve your problem.
Matrix matrix = new Matrix();
matrix.postScale(0.5f, 0.5f);
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100, matrix, true);
Above method do postScalling of image before cropping, so you can get best result with cropped image without getting OOM error.
For more detail you can refer this blog

1- Change your imageview for bitmap
final Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.img);
2-use your bitmap to crop what you want
Bitmap croppedBmp = Bitmap.createBitmap(bitmap, x, y , width , height);
3-Take care x,y from Top and left
4- to preview your bitmap again in your imageview
imageView.setImageBitmap(croppedBmp);

If you want to crop image in any shape OR only selected part then
you can use ready made open source library

Android, rotate 18x18 pixel circle icon, result: icons of different sizes?

I'm drawing a bunch of icons on a map. Actually the icons come from the same image rotated. But on the map the images take on two different sizes, I don't know why. This is what the result looks like: http://orangesoftware.net/iconmap.png
The image file looks like this: http://orangesoftware.net/arrow18.png
The code to rotate the icon:
Matrix mtx = new Matrix();
mtx.postRotate(unit.heading);
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.arrow18);
Bitmap rotatedBMP = Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(),
bmp.getHeight(), mtx, true);
BitmapDrawable bmd = new BitmapDrawable(rotatedBMP);
Any magically insights appreciated, thanks

The cause of the variation in sizes is when a rotation is not a multiple of 90 degrees. The bmp becomes a diamond who's corners stick out beyond the ImageView holding it, thus it gets resized to fit the ImageView.
The easiest way to take care of this discrepancy is to set the ImageView's scaleType to CENTER. This will simply center the image inside without scaling it to fit.