Develop Reference

android: add bitmap to another bitmap or increase bitmap size

I need to increase the size of a bitmap in Android, like in this image:
Basically, the user save the Image1. Then, the user can open again Image1 but I need that the Image2 (that is just a white rectangle) is added to the top of the Image1. So, I need to create another image, that is the Image1 plus another image.
How can I do that?
However, I just need to "increase" the Image1 size, so if there's another way to do that please let me know.
Thanks a lot

Since you only need the rectangle on top you can do this, but replace drawRect by some drawBitmap if you want to draw another image on top.
Bitmap i1 = //load the one
int w = i1.getWidth(), h = i1.getHeight();
Bitmap i3 = Bitmap.createBitmap(i1.getConfig(), w, h + 200); //200 will be the white
Canvas surface = new Canvas(i3);
Paint white = new Paint();
white.setColor(Color.WHITE);
surface.drawRect(0, 0, 200, w, white);
surface.drawBitmap(i1, 0, 200, w, h, white);
About increasing height, you can do this with the BitmapConfig.Options, but that will streth the result to match your proportions.

Crop Bitmap with rectangle dimensions

I'm drawing a rectangle over a camera preview and i want to crop that specific region covered by the rectangle and display it in ImageView. I managed to crop the the Bitmap by using :
Bitmap croppedBmp = Bitmap.createBitmap(imageOriginal, 50, 100, 1000, 550);
Code to draw the rectangle :
Rect rect = new Rect(50, 100,1000, 550);
as you can see i'm using the same parameters but i'm not getting the desired result. What i'm missing here ?. Thank you in advance.
Camera Preview :
Cropped Bitmap displayed in new activity :

Android creating bitmap from two bitmaps bottom bitmap not visible

I have a list of items where I am displaying a bitmap next to the item's name. This bitmap is to be created from 2 images, I have a background image with a smaller foreground image to add on top of the background.
I am seeing that the background image appears to not be present on some of my rows in my list. It is not consistent when and which row has the combined bitmap without the background. It is not always the same row where the combined bitmap does not have the background and it is not always the first or not always the last row where the bitmap does not have the background. And sometimes the whole list has every row with the correct image.
The image below is a mockup showing my issue.
My code for creating the combined bitmap is as follows.
Bitmap combinedBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas combinedCanvas = new Canvas(combinedBitmap);
// Add the first bitmap to the canvas (this is my background and this is what appears to be
// missing on some rows in my list on some occasions)
combinedCanvas.drawBitmap(backgroundBitmap, 0, 0, null);
// my second smaller image, on top of the first image but 1 pixel in
// from the left and 20 pixels down from the top
combinedCanvas.drawBitmap(foregroundBitmap, 1, 20, null);
return combinedBitmap;
Note: My backgroundBitmap is generated from a Drawable using the following code
Bitmap backgroundBitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
drawable.getMinimumHeight(),
Bitmap.Config.ARGB_8888);
backgroundBitmap.setDensity(resources.getDisplayMetrics().densityDpi);
Canvas canvas = new Canvas(backgroundBitmap);
drawable.draw(canvas);
Any suggestions of what I have wrong or even where to look to try and resolve this would be greatly appreciated.
EDIT: I have tested adding a colour to the background of my combinedCanvas to try and see where the image generation is going wrong by adding the following code
// TEMP: fill the canvas in red for now so I can see which combinedBitmaps are missing
// the background image
combinedCanvas.drawColor(Color.RED);
Now the rows which do not have the background are coloured in red. This indicates that the code above to create the combined canvas is somehow not adding the backgroundBitmap. I have checked and my background image is not null for every row in my list.

This method works fine for me. It's in C# (Xamarin), you'll have to translate it to Java I'm afraid.
public static Bitmap CombineImages(Bitmap background, Bitmap foreground)
{
int width = background.Width, height = background.Height;
Bitmap cs = Bitmap.CreateBitmap(width, height, Bitmap.Config.Argb8888);
Canvas comboImage = new Canvas(cs);
background = Bitmap.CreateScaledBitmap(background, width, height, true);
comboImage.DrawBitmap(background, 0, 0, null);
int top = (int)(0.05 * height);
int left = (int)(width - (foreground.Width + (width * 0.05)));
comboImage.DrawBitmap(foreground, left, top, null);
return cs;
}
The left and top are hardcoded for my requirements, it would be better to pass them in as arguments.

Android:Draw image in the center of another image

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);

Android Development: Bitmap and rectangles?

Can someone explain what the rect does in: canvas.drawBitmap(bmp,scr ,dst ,null);
Because I have tried and tried to make any sense of this but I simply don't understand what the two rectangles does.
My goal is to display a portion the bitmap instead of the whole image.
//Simon

Rect src = new Rect(0, 0, 50, 50);
Rect dst = new Rect(50, 50, 200, 200);
canvas.drawBitmap(originalBitmap, src, dst, null);
This code specifies that you want to copy a rectangle with the dimensions 50 width / 50 height of the source starting at position 0x 0y, and draw into the destination bitmap starting at position 50x / 50y and occupy it until 200x 200y - therefore stretching a bit - because as the source is only 50 pixels long, to stretch to 200x and 200y the copy will end up with the size 150width / 150 height.

The Android documentation seems to explain this method quite well.
drawBitmap Documenation
From reading the documentation it appears you can do what you want by specifying a source Rect, which will be the rectangle(subset) from the original bitmap, and it will then be translated into the dest Rectangle.
Bitmap picture; //Assume this is a 1024x768 image and has been initialized.
#Override
public void onDraw(Canvas canvas){
//To Draw only the top left corner of the image
Rect src = new Rect(0,0,512,368);
Rect dest = new Rect(0,0,512,368);
canvas.drawBitmap(picture, src, dest, null);
}