Develop Reference

The transparent pixels in my Bitmap shown as white

I'm using c code to get frame from a gif file and it's working fine using ffmpeg library av_read_frame, then I convert the returned image from this format BGRA to ARGB format using this method libyuv::ABGRToARGB.
In the java part I receive the bitmap and when I put it in the ImageView the transparent pixels drawn white.
Bitmap bitmap= Bitmap.createBitmap(150, 150, Bitmap.Config.ARGB_8888);
getGifFrame(gifFile,bitmap); //native method which get image frame from gif file.
imageTest.setImageBitmap(backgroundBitmap);//this bitmap in debug mode I can see that it has transparent pixels, but in drawn it appears white!
even when I loop on the returned bitmap pixels and check for each pixel I find them transparent!
for (int x = 0; x < b.getWidth(); x++)
{
for (int y = 0; y < b.getHeight(); y++)
{
int color = b.getPixel(x, y);
if (color == Color.WHITE)//This condition never occurred
{
b.setPixel(x, y, Color.TRANSPARENT);
}
}
}
Nothing happened and it's still white. Then I did convert all transparent pixels to TRANSPARENT !! and guess what, It's working!
else if (color == Color.TRANSPARENT)
{
b.setPixel(x, y, Color.TRANSPARENT);
}
I don't understand why that happen. Any help would be appreciated.
EDIT 1:
I get all pixels from the bitmap and set them again without doing anything and it worked also!?
bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
bitmap.setPixels(pixels, 0, width, 0, 0, width,height);

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

Replacing a color in a Bitmap

I have images which I display in my app. They are downloaded from the web. These images are pictures of objects on an almost-white background. I want this background to be white (#FFFFFF). I figure, if I look at pixel 0,0 (which should always be off-white), I can get the color value and replace every pixel in the image having that value with white.
This question has been asked before and the answer seems to be this:
int intOldColor = bmpOldBitmap.getPixel(0,0);
Bitmap bmpNewBitmap = Bitmap.createBitmap(bmpOldBitmap.getWidth(), bmpOldBitmap.getHeight(), Bitmap.Config.RGB_565);
Canvas c = new Canvas(bmpNewBitmap);
Paint paint = new Paint();
ColorFilter filter = new LightingColorFilter(intOldColor, Color.WHITE);
paint.setColorFilter(filter);
c.drawBitmap(bmpOriginal, 0, 0, paint);
However, this isn't working.
After running this code, the entire image seems to be the color I was wanting to remove. As in, the entire image is 1 solid color now.
I was also hoping to not have to loop through every pixel in the entire image.
Any ideas?

Here is a method I created for you to replace a specific color for the one you want. Note that all the pixels will get scanned on the Bitmap and only the ones that are equal will be replaced for the one you want.
private Bitmap changeColor(Bitmap src, int colorToReplace, int colorThatWillReplace) {
int width = src.getWidth();
int height = src.getHeight();
int[] pixels = new int[width * height];
// get pixel array from source
src.getPixels(pixels, 0, width, 0, 0, width, height);
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
int A, R, G, B;
int pixel;
// iteration through pixels
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
// get current index in 2D-matrix
int index = y * width + x;
pixel = pixels[index];
if(pixel == colorToReplace){
//change A-RGB individually
A = Color.alpha(colorThatWillReplace);
R = Color.red(colorThatWillReplace);
G = Color.green(colorThatWillReplace);
B = Color.blue(colorThatWillReplace);
pixels[index] = Color.argb(A,R,G,B);
/*or change the whole color
pixels[index] = colorThatWillReplace;*/
}
}
}
bmOut.setPixels(pixels, 0, width, 0, 0, width, height);
return bmOut;
}
I hope that helped :)

how to resize the image and its quality not be change in android?

I am creating an application and want to setup Image . I do not want the images in same size, but same image quality. how to resize that image but same image quality in android ?
i'm using this method to resize the image
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile
.getAbsolutePath());
int h = myBitmap.getHeight() / 20;
int w = myBitmap.getWidth() / 20;
Bitmap scaled = Bitmap.createScaledBitmap(myBitmap, w, h,
true);
imageTab.setImageBitmap(scaled);

Pass btimap you want to resize and size in which you want it to resize in following method
public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth)
{
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// CREATE A MATRIX FOR THE MANIPULATION
Matrix matrix = new Matrix();
// RESIZE THE BIT MAP
matrix.postScale(scaleWidth, scaleHeight);
// "RECREATE" THE NEW BITMAP
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
return resizedBitmap;
}

Your requirement makes no sense. Whenever you resize it the quality will be changed. Downscaling will make your image lose image data like thin lines etc, and upscaling will make your image blurred and lose clarity.
This is because you only have so much image data with you, and you cannot arbitrarily change the amount of data you have to produce good quality images.
That said, using a format like PNG over JPG can help you save some of the quality at least, as JPG compresses the data even more.

Here is code snippet ..
private static BufferedImage resizeImage(BufferedImage originalImage, int type){
BufferedImage resizedImage = new BufferedImage(IMG_WIDTH, IMG_HEIGHT, type);
Graphics2D g = resizedImage.createGraphics();
g.drawImage(originalImage, 0, 0, IMG_WIDTH, IMG_HEIGHT, null);
g.dispose();
return resizedImage;
}
BufferedImage resizeImagePng = resizeImage(originalImage, type);
ImageIO.write(resizeImagePng, "png", new File("Image PAth"));

android semitransparent bitmap background is black

I'm trying to create semitransparent bitmaps, I used this code:
private Bitmap SemiTransparent(Bitmap bitmap, int opacity) {
// Create an array to hold the data of bitmap for which semi transparent bitmap is to be obtained
int[] data = new int[(int)(bitmap.getWidth()) + 1];
for (int y = 0; y < bitmap.getHeight(); ++y)
{
// Get a single line of data
bitmap.getPixels(data, 0, bitmap.getWidth(), 0, y,bitmap.getWidth(), 1);
// Reset the alpha values
for (int x = bitmap.getWidth(); x>0; --x)
{
data[x] = (data[x] & 0x00ffffff) | (opacity << 24);
}
//fill alphaBitmap data
bitmap.setPixels(data, 0, bitmap.getWidth(), 0, y, bitmap.getWidth(), 1);
}
return bitmap;
}
The only problem is the background (transparent) color is always black - how can I modify this to make the background Color completely transparent and the rest still semitransparent?

Use this method to make a bitmap transparent:
/**
* #param bitmap The source bitmap.
* #param opacity a value between 0 (completely transparent) and 255 (completely
* opaque).
* #return The opacity-adjusted bitmap. If the source bitmap is mutable it will be
* adjusted and returned, otherwise a new bitmap is created.
*/
private Bitmap adjustOpacity(Bitmap bitmap, int opacity)
{
Bitmap mutableBitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas = new Canvas(mutableBitmap);
int colour = (opacity & 0xFF) << 24;
canvas.drawColor(colour, PorterDuff.Mode.DST_IN);
return mutableBitmap;
}
See an explanation here:
http://blog.uncommons.org/2011/01/12/adjusting-the-opacity-of-an-android-bitmap/
In the blog-post it checks if the bitmap is mutable or not - which can cause problems if the bitmap is mutable but doesn't have the config ARGB_8888 - so use my method instead.