Develop Reference

Overlay an image on canvas

Is there possible to overlay an image on camera preview butt that image for example a coin should look like an original view, as I will move my camera it will remains in its place just like real objects as seen in camera.
I have done with overlaying a static image on camera preview but that's not my requirement.
please suggest.
thanks.

to overlay an image up to another image use this method.
public Bitmap overlayChange(Bitmap all, Bitmap scaledBorder) {
final int width = change.getWidth();
final int height = change.getHeight();
all = Bitmap.createScaledBitmap(change, width, height, true);
Bitmap mutableBitmap = all.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas = new Canvas(mutableBitmap);
scaledBorder = Bitmap.createScaledBitmap(border, width, height, true);
canvas.drawBitmap(scaledBorder, 0, 0, null);
return mutableBitmap;
}
and to use it simple
yourBitmap = overlayChange(yourBitmap , YourOtherBitmap);

Android water mark

I have some question about water mark within android code!
Following code showed my idea about WaterMark!
However,It does not work normally.
e.g. only the image end with .png can be watered mark
Is there a scheme about water mark(.jpeg, .jpg, .wbmp, .bmp, .png or others)
protected static Bitmap getDrmPicture(Context context,String path){
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap originMap = BitmapFactory.decodeFile (path,options);
Bitmap waterMark = BitmapFactory.decodeResource(context.getResources(), R.drawable.close);
InputStream input;
byte[] b;
Bitmap waterMark = null;
try {
input = context.getResources().openRawResource(R.drawable.lock);
b = new byte[input.available()];
input.read(b);
waterMark = DecodeUtils.requestDecode(jc, b, null);
}catch(IOException e){
}
int w = originMap.getWidth();
int h = originMap.getHeight();
int ww = waterMark.getWidth();
int wh = waterMark.getHeight();
Bitmap newb = Bitmap.createBitmap(w, h,Bitmap.Config.ARGB_8888;);
Canvas cv = new Canvas(newb);
cv.drawBitmap(originMap, 0, 0, null);
cv.drawBitmap(waterMark, w - ww, h - wh, null);
cv.save(Canvas.ALL_SAVE_FLAG);
cv.restore();
return newb;
}
Thanks !

This is the code I use to apply watermark to a jpeg, it should work for you too,
public Bitmap applyWatermarkColorFilter(Drawable drawable) {
Bitmap image = ((BitmapDrawable)drawable).getBitmap();
Bitmap result = Bitmap.createBitmap(image.getWidth(), image.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(result);
canvas.drawBitmap(image, 0, 0, null);
Bitmap watermark = BitmapFactory.decodeResource(getResources(), R.drawable.watermark);
canvas.drawBitmap(watermark, image.getWidth()/2 - watermark.getWidth()/2,
image.getHeight()/2 - watermark.getHeight()/2,
null);
return result;
}
Basically after this u have to use Bitmap.compress(<arguments>) to get a jpg out of it.
Din't try for the other formats. May be it might be possible if you can extract the Bitmap out of them like how we do for jpg and png.

https://stackoverflow.com/questions/6756975/draw-multi-line-text-to-canvas
Measure height of multiline text
To center text vertically we need to know text height. Instantiate StaticLayout with text width according to your needs, for us it is simple the width of Bitmap/Canvas minus 16dp padding. The getHeight() then returns height of text.
Positioning text on Canvas
There are four simple steps to position text on Canvas:
Save the current matrix and clip with Canvas.save().
Apply translation to Canvas matrix with Canvas.translate(x,y).
Draw StaticLayout on Canvas with StaticLayout.draw(canvas).
Revert matrix translation with Canvas.restore() method.

Overlay Bitmap over another Android

hello guys i'm trying to get an image(Frame from resources) to overlay it over the original bitmap. so far i couldn't make my Bitmap goes into the frame as the frame always empty. the original bitmap is now showing inside the frame.
here is my code that i'm using to accomplish this.
Canvas canvas = new Canvas();
Bitmap border = null;
Bitmap scaledBorder = null;
border = BitmapFactory.decodeResource(getResources(), R.drawable.frame1);
int width = bmp.getWidth();
int height = bmp.getHeight();
scaledBorder = Bitmap.createScaledBitmap(border,width,height, false);
canvas.drawBitmap(scaledBorder, 0, 0, new Paint());
view.setImageBitmap(scaledBorder);
bmp as my original Bitmap from Gallery or Camera. i can't find away to put them together. only the frame will appear but not the bmp.
thanks in advance.

thanks man i figured it out by own. using this
void hm1(){
Bitmap border = BitmapFactory.decodeResource(getResources(), R.drawable.vignette2);
int width = bmp.getWidth();
int height = bmp.getHeight();
change = Bitmap.createScaledBitmap(change, width, height, false);
Canvas canvas = new Canvas(change);
Bitmap scaledBorder = Bitmap.createScaledBitmap(border,width,height, false);
canvas.drawBitmap(scaledBorder, 0, 0,null);
//canvas.drawBitmap(k, 0, 0, null);
view.setImageBitmap(change);
}
by adding this method on any click button , menu etc you can draw two bitmaps over each other.
P.S : Bitmap change is another bitmap from the original one as i don't want the user to apply the Overlay on the original method but on the changed one.
hope the answer helps someone. thanks

Bottom line, first you need to add your original image to the canvas, then the border, then place the canvas on the view. Your best bet is to do this in an onDraw() method. Something like this should work:
#Override
void onDraw (Canvas canvas)
{
canvas.drawBitmap(bmp,0,0,new Paint())
Bitmap border = null;
Bitmap scaledBorder = null;
border = BitmapFactory.decodeResource(getResources(), R.drawable.frame1);
int width = bmp.getWidth();
int height = bmp.getHeight();
scaledBorder = Bitmap.createScaledBitmap(border,width,height, false);
canvas.drawBitmap(scaledBorder, 0, 0, new Paint());
}
Alternatively, you could call the draw() function from the view.
canvas.drawBitmap(bmp,0,0,new Paint())
Bitmap border = null;
Bitmap scaledBorder = null;
border = BitmapFactory.decodeResource(getResources(), R.drawable.frame1);
int width = bmp.getWidth();
int height = bmp.getHeight();
scaledBorder = Bitmap.createScaledBitmap(border,width,height, false);
canvas.drawBitmap(scaledBorder, 0, 0, new Paint());
view.draw(canvas);

How to convert PictureDrawable into ScaleDrawble?

I am trying to scale a picture drwable which I get from svg-android-library. I can create the drawable but do not get how to scale it.
Here is the code I tried:
Drawable drawable = svg.createPictureDrawable();
int size = 108;
Bitmap img = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(img);
//resize drawable here according to screen width
drawable = new ScaleDrawable(drawable, 0, size*2, size*2).getDrawable();
drawable.setBounds(0, 0, size*2, size*2);
drawable.draw(canvas);
Any suggestions?

I used
Picture picture = svg.getPicture();
and then draw it with a new Rect which will stretch it to fit the new Rect
canvas.drawPicture(picture, newRect);

android - adding a String over a Drawable image?

I'm trying to add a String to a Drawable image. I'm currently not using a Panel to draw and I'd like to keep it that way. Any ideas or do I need to invoke an onDraw() method?
My image is showing up with this code:
Drawable image = getResources().getDrawable(tile_types[tileType]);
setImageDrawable(image);
I'd like to add a String over this image.
Thanks.

Sam's answer was my starting point, but the image didn't show up, only the text (I use it on a Google Map). Finally I got it working with a LayerDrawable. Here is my solution:
private Drawable createMarkerIcon(Drawable backgroundImage, String text,
int width, int height) {
Bitmap canvasBitmap = Bitmap.createBitmap(width, height,
Bitmap.Config.ARGB_8888);
// Create a canvas, that will draw on to canvasBitmap.
Canvas imageCanvas = new Canvas(canvasBitmap);
// Set up the paint for use with our Canvas
Paint imagePaint = new Paint();
imagePaint.setTextAlign(Align.CENTER);
imagePaint.setTextSize(16f);
// Draw the image to our canvas
backgroundImage.draw(imageCanvas);
// Draw the text on top of our image
imageCanvas.drawText(text, width / 2, height / 2, imagePaint);
// Combine background and text to a LayerDrawable
LayerDrawable layerDrawable = new LayerDrawable(
new Drawable[]{backgroundImage, new BitmapDrawable(canvasBitmap)});
return layerDrawable;
}

Drawable image = getResources().getDrawable(tile_types[tileType]);
// Store our image size as a constant
final int IMAGE_WIDTH = image.getIntrinsicWidth();
final int IMAGE_HEIGHT = image.getIntrinsicHeight();
// You can also use Config.ARGB_4444 to conserve memory or ARGB_565 if
// you don't have any transparency.
Bitmap canvasBitmap = Bitmap.createBitmap(IMAGE_WIDTH,
IMAGE_HEIGHT,
Bitmap.Config.ARGB_8888);
// Create a canvas, that will draw on to canvasBitmap. canvasBitmap is
// currently blank.
Canvas imageCanvas = new Canvas(canvasBitmap);
// Set up the paint for use with our Canvas
Paint imagePaint = new Paint();
imagePaint.setTextAlign(Align.CENTER);
imagePaint.setTextSize(16f);
// Draw the image to our canvas
image.draw(imageCanvas);
// Draw the text on top of our image
imageCanvas.drawText("Sample Text",
IMAGE_WIDTH / 2,
IMAGE_HEIGHT / 2,
imagePaint);
// This is the final image that you can use
BitmapDrawable finalImage = new BitmapDrawable(canvasBitmap);

If your resulted text looks "angular" due to resizing, it's better to use TextPaint instead of plain Paint with these parameters:
TextPaint textPaint = new TextPaint(TextPaint.ANTI_ALIAS_FLAG | TextPaint.LINEAR_TEXT_FLAG);