Develop Reference

How to set exactly position another view when zoom or drag (left, right, up, down) image?

I met a big trouble in this case.
I have a imageview (green icon) added on Image background. Green icon's position is set dynamically(Pic 1)
This Image can zoom in, zoom out, drag left, right, up, down. I want to to move exactly imageview's position (green icon) when zoom or drag image background.
How can I map imageview's position (green icon) with Image background when I zoom, drag Image background?
Picture 2: Image background is zoomed but green icon view does not map with image background, it's wrong position.
Can you suggest me some solution, direction or scripts. Thanks all!

use following function which will overlay your image bitmap with mark image bitmap and return new bitmap which you can use to display
private Bitmap overlay(Bitmap bmp1, Bitmap bmp2, float left, float top) {
Bitmap bmOverlay = Bitmap.createBitmap(bmp1.getWidth(), bmp1.getHeight(), bmp1.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(bmp1, new Matrix(), null);
canvas.drawBitmap(bmp2, left, top, null);
return bmOverlay;
}
eg :-
Bitmap border = null;
Bitmap scaledBorder = null;
border = BitmapFactory.decodeResource(getResources(), R.drawable.palette);
scaledBorder = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
ImageView im = (ImageView) findViewById(R.id.imageView);
im.setImageBitmap(overlay(border, scaledBorder, 0, 0));// replace both 0,0 point with your mark point

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.

Water reflection effect on bitmap

I trying to achieve water reflection effect on bitmap. As I saw some apps called water reflection. I know how to do the reflection of the image but the wave on the image is what making me confused on how it is done.
see this image for example
I did many apps on bitmap manipulation but this is quite hard to achieve.
So any idea on where to start. Just an idea to start can be helpful.

For any one needed, I tried some simple tricks to get as closer as water reflection effect. It is not great but it looks fine to me.
I used two methods
Bitmap reflection method (give bitmap as a parameter)
public static Bitmap Reflection(Bitmap imageBitmap) {
int width = imageBitmap.getWidth();
int height = imageBitmap.getHeight();
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
Bitmap reflectionImage = Bitmap.createBitmap(imageBitmap, 0,
0, width, height , matrix, false);
Bitmap newbit=Bitmap.createScaledBitmap(reflectionImage, reflectionImage.getWidth()/8, reflectionImage.getHeight()/8, true);
Bitmap newbit1=Bitmap.createScaledBitmap(newbit, newbit.getWidth()*8, newbit.getHeight()*8, true);
Bitmap scalednew=Bitmap.createScaledBitmap(newbit1, width, height-(height/4), true);
Bitmap newscaledone=overlay(scalednew);
reflectionImage=newscaledone;
Bitmap reflectedBitmap = Bitmap.createBitmap(width,
(height + height), Config.ARGB_8888);
Canvas canvas = new Canvas(reflectedBitmap);
canvas.drawBitmap(imageBitmap, 0, 0, null);
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height, defaultPaint);
canvas.drawBitmap(reflectionImage, 0, height , null);
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawRect(0, height, width, reflectedBitmap.getHeight()
, paint);
return reflectedBitmap;
}
Bitmap overlay method. I am taking a wave bitmap with some opacity to overlay on the reflected image. So that it may look like water.
Bitmap wavebitmap=BitmapFactory.decodeResource(getResources(), R.drawable.waves1);
private static Bitmap overlay( Bitmap bmp2) {
Bitmap bmp1=WaterReflectionMainActivity.wavebitmap;
Bitmap bmp1new =Bitmap.createScaledBitmap(bmp1, bmp2.getWidth(), bmp2.getHeight(), true);
Bitmap bmOverlay = Bitmap.createBitmap(bmp1new.getWidth(), bmp1new.getHeight(), bmp1new.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(bmp2, new Matrix(), null);
canvas.drawBitmap(bmp1new, new Matrix(), null);
return bmOverlay;
}
Well this is my version of water effect, I know this looks shit.
So if anyone still got some better effect please share your code .
thank you

Tutorial related to this: http://www.xaraxone.com/webxealot/workbook34/page_4.htm
Also have a read at this question: Add water effect on bitmap android.
Have a read at both of them, i hope you will get an idea from this
You may also want to look through these: 1, 2, 3

This is just an idea but basically, what you need is to apply a deformation on the bottom part of the image, meaning that for each pixel on the bottom half, you compute a position to get it's color from the top picture.
Here's a pseudo code to give you a hint :
for (int x = 0; x < width; x++) {
for (int y = 0; y < img.height; y++) {
// Compute a position on the original image
// tweak the values heres to get the effect you want
sourceX = x + (int) (cos(10000.0 / y) * 20);
sourceY = img.height - y - 1 +(int)( sin(y* 0.5) * 20);
// Maybe check the range of sourceX and source Y
int color = img.getColor(sourceX, sourceY)
outptut.setColor(x, y + img.height, color);
}
}

you can achieve this by masking may this code will help you
http://www.seeques.com/22527681/how-can-do-this-effect-in-android-may-be-android-bitmap-masking-effect.html
EDIT
also see this for reference
http://code.google.com/p/android-ripple-demo/source/browse/#svn%2Ftrunk%2Fsrc%2Fcom%2Fkesalin%2FRippleDemo
https://github.com/esteewhy/whater
http://code.google.com/p/waterrippleeffect/source/browse/trunk/src/com/example/android/watereffect/WaterEffectView.java?r=3
android noise effect on bitmap

Captured image stretches wrongly after cropping in Android

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

Retrieving the image and add caption to it

I wanted to create an app by taking images from the sd card and add caption to it. Also I wanted to move the caption as per our wish and place it somewhere as desired and save it .can you please suggest an idea for doing this. Also if we want to add a caption to the existing image from SD card then , do we need to have database for doing this. or can it be saved directly to the SD card.

Refer This Answer
You can put an EditText and Write into it and after writting you first convert it to Bitmap like
Bitmap bmp = Bitmap.createBitmap(mEditText.getDrawingCache());
Now you can add created image bmp to your original image like this
call :
Bitmap combined = combineImages(bgBitmap,bmp);
public Bitmap combineImages(Bitmap background, Bitmap foreground) {
int width = 0, height = 0;
Bitmap cs;
width = getWindowManager().getDefaultDisplay().getWidth();
height = getWindowManager().getDefaultDisplay().getHeight();
cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
background = Bitmap.createScaledBitmap(background, width, height, true);
comboImage.drawBitmap(background, 0, 0, null);
comboImage.drawBitmap(foreground, matrix, null);
return cs;
}

Use canvas (Custom Views) for it..
I think this is the only way to make one view (Image in one canvas) on other view (caption in other canvas) on it. So in this you have to complete knowledge of how views draw on canvas and how to move to that views. And using canvas you can also smoothly move your views on screen.
After creating custom views you can save those views in Bitmap, now you can also combine those images to one bitmap..
(Here Customeviews are ImageViews, TextViews, EditText etc..)
All the best. :-)

USe like this.
cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
background = Bitmap.createScaledBitmap(background, width, height, true);
comboImage.drawBitmap(background, 0, 0, null);
comboImage.drawText("title", x, y, paint);