I want to capture an image from my camera and crop the captured image at specified co-ordinates then draw it on the middle of another image. The following code doesn't crash, but the captured image is screwing up, since the image stretches wrong.
Where am I going wrong?
Merry X'mas!
//Get the bottom image Bitmap
Bitmap bottomImage = BitmapFactory.decodeResource(getResources(), SelectDollarActivity.selectedImageId);
//Get the captured image Bitmap
Bitmap capturedImage = BitmapFactory.decodeFile(CaptureImage.cImagePath) ;
//************ CROP THE CAPTURED IMAGE *******************
int targetBitmapWidth = bottomImage.getWidth();
int targetBitmapHeight = bottomImage.getHeight() ;
//create a Bitmap with specified width & height
Bitmap clippedBitmap = Bitmap.createBitmap(targetBitmapWidth, targetBitmapHeight, Bitmap.Config.ARGB_8888);
//Construct a canvas with the specified bitmap to draw into.
Canvas canvas = new Canvas(clippedBitmap);
//************** cropping process goes HERE.........
//Create a new rectangle with the specified coordinates
RectF rectf = new RectF(left, top, right, bottom);
//Create an empty path
Path path = new Path();
//Add a closed oval contour to the path
path.addOval(rectf, Path.Direction.CW);
//Intersect the current clip with the specified path : CROPPING
canvas.clipPath(path);
canvas.drawBitmap(capturedImage, null, new Rect(0, 0, targetBitmapWidth, targetBitmapHeight), null);
//******** MERGING PROCESS *******************
//Construct a canvas with the specified bitmap to draw into.
Canvas combo = new Canvas(bottomImage);
// Then draw the second on top of that
combo.drawBitmap(clippedBitmap, 0f, 0f, null);
// bottomImage is now a composite of the two. so, display the bottom image
//************** DISPLAY THE MERGED IMAGE ****************
((ImageView)findViewById(R.id.billImage)).setImageBitmap(bottomImage);
Documentation states that drawBitmap accepts two more arguments, width and heights. In your code,
combo.drawBitmap(clippedBitmap, 0f, 0f, null);
only has the positioning.
You will need to set a few more arguments of course, but it should work :D
Related
I am trying to further process a Camera2 image. Because the cameras in devices have different rotations and flipped based on back and front camera, I use transforms to properly rotate it.
transformationMatrix is that matrix for the front camera that has 270 rotation.
Then from that transformed camera image, I want to copy a scrolling window to another bitmap. I want to retain that bitmap/state and draw a line before drawing finalBitmapWithScanner on the phone screen.
Is there a way to do this more efficiently and fast? The second line takes 200ms to complete which is the main issue here.
Canvas canvas = new Canvas(tempBitmap);
canvas.drawBitmap(cameraBitmap, transformationMatrix, paint); // <= 200ms
Rect src = new Rect((int) lastXPos, 0, (int) mXPos, mViewHeight);
Canvas canvas2 = new Canvas(finalBitmap);
canvas2.drawBitmap(tempBitmap, src, src, paint);
Canvas canvas3 = new Canvas(finalBitmapWithScanner);
canvas3.drawBitmap(finalBitmap, 0, 0, paint);
canvas3.drawLine(mXPos, 0, mXPos, mViewHeight/2, scrollerPaint);
transformationMatrix.reset();
transformationMatrix.setRotate(270, imageHeight, 0);
transformationMatrix.postTranslate(-imageHeight, 0);
transformationMatrix.postScale(scaleFactor, scaleFactor);
transformationMatrix.postScale(-1f, 1f, mViewWidth / 2f, mViewHeight / 2f);
There are bunch of ways you can try to achieve fast rendering:
You can pass parameters "paint" an null.
also you can use function CreateScaledBitmap and notice you have to set scale and size before rendering as see in below:
As you can see in documentation enter link description here; you have to resize and rescale your bitmap before rendering so you can use code below for your BitmapFactory.Options :
mBitmapOptions.inScaled = true;
mBitmapOptions.inDensity = srcWidth;
mBitmapOptions.inTargetDensity = dstWidth;
// will load & resize the image to be 1/inSampleSize dimensions
mCurrentBitmap = BitmapFactory.decodeResources(getResources(),
mImageIDs, mBitmapOptions);
use canvas.restore() after draw func.
So i have an problem with method of Canvas.DrawBitmap(), that draws unexpected result.
Lets see my example:
Source image
I have two cases(just for test):
I want to draw Red rectangle from 0,0 and give for him size 1/4 of image,also i want to draw this bitmap in same size(1/4) and put to Bottom.Right place.
Draw again Red rectangle with same conditions(starts from Top.Left(0,0) and size 1/4 of image) and draw part of bitmap and shows as Rectangle with 1/4 size(Bottom.Right).
Case #1
i'm doing this:
//source imageview
Source.SetImageResource(Resource.Drawable.lena30);
//bitmap
bt = ((BitmapDrawable)Source.Drawable).Bitmap.Copy(Bitmap.Config.Argb8888, true);
//second imageview, where i fill result
Draw.SetImageBitmap(bt);
can = new Canvas(bt);
Paint paint = new Paint();
paint.Color = Color.Red;
paint.SetStyle(Paint.Style.Fill);
//draw Red Rect with 1/4 size and locate Top.Left
can.DrawRect(0,0,bt.Width/2,bt.Height/2,paint);
//redraw new bitmap(all subset) and locate to Bottom.Right with 1/4 size
can.DrawBitmap(bt, null, new Rect(bt.Width/2, bt.Height / 2, bt.Width, bt.Height), null);
and the result is :
Case #2
same,but getting now part of bitmap(not full subset of bitmap):
//source imageview
Source.SetImageResource(Resource.Drawable.lena30);
//bitmap
bt = ((BitmapDrawable)Source.Drawable).Bitmap.Copy(Bitmap.Config.Argb8888, true);
//second imageview, where i fill result
Draw.SetImageBitmap(bt);
can = new Canvas(bt);
Paint paint = new Paint();
paint.Color = Color.Red;
paint.SetStyle(Paint.Style.Fill);
//draw Red Rect with 1/4 size and locate Top.Left
can.DrawRect(0,0,bt.Width/2,bt.Height/2,paint);
//redraw new bitmap(not full,only part of Source Rectangle) and locate to Bottom.Right with 1/4 size
can.DrawBitmap(bt, new Rect(bt.Width/2,0,bt.Width,bt.Height), new Rect(bt.Width/2, bt.Height / 2, bt.Width, bt.Height), null);
So i cant understand,why that happens?(Why image no scaling to fit size and duplicate Rectangles!?).
Any ideas? Thanks!
The issue is that you're drawing the bt Bitmap onto itself, which is causing it to recursively draw until it hits a minimum size limit. It'll take a little reworking of your code, but you'll need to create an intermediate Bitmap and Canvas on which to do your drawing, then set that Bitmap on the target ImageView.
Source.SetImageResource(Resource.Drawable.lena30);
bt = ((BitmapDrawable) Source.Drawable).Bitmap.Copy(Bitmap.Config.Argb8888, true);
Paint paint = new Paint();
paint.Color = Color.Red;
paint.SetStyle(Paint.Style.Fill);
Canvas canSource = new Canvas(bt);
canSource.DrawRect(0, 0, bt.Width / 2, bt.Height / 2, paint);
Bitmap btDraw = Bitmap.CreateBitmap(bt.Width, bt.Height, Bitmap.Config.Argb8888);
Canvas canDraw = new Canvas(btDraw);
canDraw.DrawBitmap(bt, null, new Rect(0, 0, bt.Width, bt.Height), null);
canDraw.DrawBitmap(bt, null, new Rect(bt.Width / 2, bt.Height / 2, bt.Width, bt.Height), null);
Draw.SetImageBitmap(btDraw);
NB: I've never used Xamarin, so please forgive any syntax errors in my attempted translation.
I'm trying to save a screenshot of my current Activity, but not the whole view, just part of it.
In my case:
My activity
At the attached image, i want to save a bitmap constructed from views B,C & D.
B is a linear layout, C is a pure bitmap, and D is a relative layout.
To my understanding, one way to go is creating a canvas, add all 'elements' into it and finally have the custom bitmap desired.
I'm having trouble with the following code:
iViewBHeight= viewB.getHeight();
// Prepare empty bitmap as output
Bitmap result = Bitmap.createBitmap(bitmapC.getWidth(),bitmapC.getHeight() + iViewBHeight, Config.ARGB_8888);
// Flush source image into canvas
Canvas canvas = new Canvas(result);
// Draw bitmap C to canvas 'under' view B
canvas.drawBitmap(bitmapC, 0, iViewBHeight, null);
// Draw view B to canvas
viewB.setDrawingCacheEnabled(true);
viewB.buildDrawingCache(true);
canvas.drawBitmap(Bitmap.createBitmap(viewB.getDrawingCache()), 0, 0, null);
viewB.setDrawingCacheEnabled(false);
// Desired bitmap is at 'result'
The result is that bitmap C is drawn Ok, but view B is too large and extends the bitmap.
I didn't try adding view D..
Can anyone help me? Maybe there are better ways achieving my goal?
Thanks!
I think the easiest way to accomplish that is to grab a screenshot of the Activity's entire content, then crop off the A View. The Canvas#drawBitmap(Bitmap bmp, Rect src, Rect dest, Paint pnt) overload does this easily. The Rect src describes section of the source Bitmap you're copying, while dest is the section of the destination Bitmap that the source will be drawn in. (NB: the Rects don't have to be the same size.)
I believe the following method should do what you want, if I'm following you correctly.
private Bitmap capture()
{
View actContent = findViewById(android.R.id.content);
Bitmap result = Bitmap.createBitmap(actContent.getWidth(),
actContent.getHeight() - viewA.getHeight(),
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(result);
actContent.setDrawingCacheEnabled(true);
Rect src = new Rect(0, viewA.getHeight(), actContent.getWidth(), actContent.getHeight());
Rect dest = new Rect(0, 0, result.getWidth(), result.getHeight());
canvas.drawBitmap(actContent.getDrawingCache(), src, dest, null);
actContent.setDrawingCacheEnabled(false);
return result;
}
my goal is to create an app that allows users to take a picture with the camera and then add some images on it just like "face in hole" but reversed.
I'm already capable of showing the camera preview while display a imageview, but when i take the picture it has a different resolution so the bitmap over the photo is misplaced.
I've wrote this code but it isn't very accurate:
canvas.drawBitmap(cameraBitmap, 0f, 0f, null); //drawing the picture just taken on the canvas
float posx, posy, newx,newy;
RectF r = new RectF();
i.getImageMatrix().mapRect(r); // i is the imageview of the bitmap
posx= r.left;
posy= r.top;
newx=(posx*newImage.getWidth())/screenWidth;
newy = (posy*newImage.getHeight())/screenHeight;
canvas.drawBitmap( ((BitmapDrawable)i.getDrawable()).getBitmap(),newx,newy,null);
My question is: there's a better and more accurate way to place a bitmap on the picture with the new resolution keeping bitmap scale and rotation info?
Thanks in advance.
I have one image image 1 and one is coming from server that is image 2 i am trying to draw second one just at the center of the first. as result i want single image like in pic .
This should do what you're looking for:
The backgroundBitmap variable would be your image1 and the bitmapToDrawInTheCenter would be your image2.
public void centerImageInOtherImage()
{
Bitmap backgroundBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
Bitmap bitmapToDrawInTheCenter = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_search);
Bitmap resultingBitmap = Bitmap.createBitmap(backgroundBitmap.getWidth(), backgroundBitmap.getHeight(), backgroundBitmap.getConfig());
Canvas canvas = new Canvas(resultingBitmap);
canvas.drawBitmap(backgroundBitmap, new Matrix(), null);
canvas.drawBitmap(bitmapToDrawInTheCenter, (backgroundBitmap.getWidth() - bitmapToDrawInTheCenter.getWidth()) / 2, (backgroundBitmap.getHeight() - bitmapToDrawInTheCenter.getHeight()) / 2, new Paint());
ImageView image = (ImageView)findViewById(R.id.myImage);
image.setImageBitmap(resultingBitmap);
}
Courtesy : Draw text/Image on another Image in Android
Drawing images over each other is fairly simple with Canvas. Canvas basically acts as the drawing board to draw text/Image. You just need to construct a canvas with the first Image and then draw the second Image at the center as shown below
/* This ImageOne will be used as the canvas to draw an another image over it. Hence we make it mutable using the copy API
as shown below
*/
Bitmap imageOne = BitmapFactory.decodeResource(getResources(), R.drawable.imageOne).copy(Bitmap.Config.ARGB_8888,true);
// Decoding the image two resource into a Bitmap
Bitmap imageTwo= BitmapFactory.decodeResource(getResources(), R.drawable.imageTwo);
// Here we construct the canvas with the specified bitmap to draw onto
Canvas canvas=new Canvas(imageOne);
/*Here we draw the image two on the canvas using the drawBitmap API.
drawBitmap takes in four parameters
1 . The Bitmap to draw
2. X co-ordinate to draw from
3. Y co ordinate to draw from
4. Paint object to define style
*/
canvas.drawBitmap(imageTwo,(imageOne.getWidth())/2,(imageOne.getHeight())/2,new Paint());
imageView.setImageBitmap(imageOne);