I need to convert a 2d integer array (subSrc) to a bitmap. Any solutions?
private Bitmap decimation(Bitmap src){
Bitmap dest = Bitmap.createBitmap(
src.getWidth(), src.getHeight(), src.getConfig());
int bmWidth = src.getWidth();
int bmHeight = src.getHeight();`enter code here`
int[][] subSrc = new int[bmWidth/2][bmWidth/2];
for(int k = 0; k < bmWidth-2; k++){
for(int l = 0; l < bmHeight-2; l++){
subSrc[k][l] = src.getPixel(2*k, 2*l); <---- ??
I looked for a method that received an 2d array (int[][]) and created a Bitmap, and found none, so I wrote one myself:
public static Bitmap bitmapFromArray(int[][] pixels2d){
int width = pixels2d.length;
int height = pixels2d[0].length;
int[] pixels = new int[width * height];
int pixelsIndex = 0;
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
pixels[pixelsIndex] = pixels2d[i][j];
pixelsIndex ++;
}
}
return Bitmap.createBitmap(pixels, width, height, Bitmap.Config.ARGB_8888);
}
I also wrote a reverse method:
public static int[][] arrayFromBitmap(Bitmap source){
int width = source.getWidth();
int height = source.getHeight();
int[][] result = new int[width][height];
int[] pixels = new int[width*height];
source.getPixels(pixels, 0, width, 0, 0, width, height);
int pixelsIndex = 0;
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
result[i][j] = pixels[pixelsIndex];
pixelsIndex++;
}
}
return result;
}
I hope you find it useful!
you can use
setPixel(int, int, int) or setPixels (int[] pixels, int offset, int stride, int x, int y, int width, int height) methos od bitmap class.
Bitmap dest = Bitmap.createBitmap(
src.getWidth()/2, src.getHeight()/2, src.getConfig());
int bmWidth = src.getWidth();
int bmHeight = src.getHeight();
for(int k = 0; k < bmWidth/2; k++){
for(int l = 0; l < bmHeight/2; l++){
dest.setPixel(k,l,src.getPixel(2*k, 2*l));
But this will be slower i think.
for the 2nd method you uhave to do something like this
int subSrc = new int[(bmWidth/2*)(bmHeight/2)];
for(int k = 0; k < bmWidth-2; k++){
subSrc[k] = src.getPixel(2*(k/bmWidth), 2*(k%bmHeight)); <---- ??
So, you are essentially trying to pull pixels out, do something to them, then make a Bitmap as a result?
The routines expect the pixels to be in a single-dimensional array, so you'll want to put them into the array more like this:
int data[] = new int[size];
data[x + width*y] = pixel(x,y);
...
Then use Bitmap.createBitmap() that accepts the single-dimensional array. You'll want to use the Bitmap.Config for ARGB in your example, since you're using b.getPixel(x,y) which always returns a color in ARGB format.
Bitmap result = Bitmap.createBitmap(data, width, height, Bitmap.Config.ARGB_8888);
Related
Anyone know how to add subtle noise to grayscale image?
I have a grayscale image that I want to add some subtle black and white noise to. Anyone know how to do this?
I'm currently using this method, but this is just generating random colors and swapping existing pixels with those colors. How can I add some subtle black and white noise to only SOME pixels on a bitmap?
public static Bitmap applyFleaEffect(Bitmap source) {
// get source image size
int width = source.getWidth();
int height = source.getHeight();
int[] pixels = new int[width * height];
// get pixel array from source
source.getPixels(pixels, 0, width, 0, 0, width, height);
// create a random object
Random random = new Random();
int index = 0;
// iteration through pixels
for(int y = 0; y < height; ++y) {
for(int x = 0; x < width; ++x) {
// get current index in 2D-matrix
index = y * width + x;
// get random color
int randColor = Color.rgb(random.nextInt(255),
random.nextInt(255), random.nextInt(255));
// OR
pixels[index] |= randColor;
}
}
// output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, source.getConfig());
bmOut.setPixels(pixels, 0, width, 0, 0, width, height);
return bmOut;
}
}
UPDATE: Adding complete code to show grayscale step, and attempted noise step
//First, apply greyscale to make Image black and white
Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, mBitmap.getConfig());
Canvas c = new Canvas(bmpGrayscale);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
cm.setSaturation(0);
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
//Apply noise after grayscale
int[] pixels = new int[width * height];
bmpGrayscale.getPixels(pixels, 0, width, 0, 0, width, height);
// a random object
Random random = new Random();
int index = 0;
// Note: Declare the c and randColor variables outside of the for loops
int co = 0;
int randColor = 0;
// iteration through pixels
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
if (random.nextInt(101) < percentNoise) {
// Skip this iteration a certain percentage of the time
continue;
}
// get current index in 2D-matrix
index = y * width + x;
co = random.nextInt(255);
randColor = Color.rgb(co, co, co);
pixels[index] |= randColor;
}
}
// output bitmap
mBitmap = Bitmap.createBitmap(width, height, bmpGrayscale.getConfig());
mBitmap.setPixels(pixels, 0, width, 0, 0, width, height);
c.drawBitmap(mBitmap, 0, 0, paint);
return bmpGrayscale;
}
First, randColor is not likely to be a gray-scale color with your code. To generate a random, gray-scale color:
int c = random.nextInt(255);
int randColor = Color.rgb(c, c, c);
With that in mind, here is how I would re-write your code (note: adjust the percentNoise parameter to your liking):
public static Bitmap applyFleaEffect(Bitmap source, int percentNoise) {
// get source image size
int width = source.getWidth();
int height = source.getHeight();
int[] pixels = new int[width * height];
// get pixel array from source
source.getPixels(pixels, 0, width, 0, 0, width, height);
// create a random object
Random random = new Random();
int index = 0;
// Note: Declare the c and randColor variables outside of the for loops
int c = 0;
int randColor = 0;
// iterate through pixels
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
if (random.nextInt(101) < percentNoise) {
// Skip this iteration a certain percentage of the time
continue;
}
// get current index in 2D-matrix
index = y * width + x;
// get random color
c = random.nextInt(255);
randColor = Color.rgb(c, c, c);
pixels[index] |= randColor;
}
}
Bitmap bmOut = Bitmap.createBitmap(width, height, source.getConfig());
bmOut.setPixels(pixels, 0, width, 0, 0, width, height);
return bmOut;
}
Based on this question asked by #ben75: Android : save a Bitmap to bmp file format
My question now is: How can I have a BMP image with the depth of 1 bit per pixel (Black & White)?
Answering my own question...
After some tough search all over the web I realized I had to create 2 things: a bitmap black and white - and did that using the approach of making all 0's for colors below 128 and 255's for the rest, like this (this is C# code, as I'm using Xamarin to code my app):
private void ConvertArgbToOneColor (Bitmap bmpOriginal, int width, int height){
int pixel;
int k = 0;
int B=0,G=0,R=0;
try{
for(int x = 0; x < height; x++) {
for(int y = 0; y < width; y++, k++) {
pixel = bmpOriginal.GetPixel(y, x);
R = Color.GetRedComponent(pixel);
G = Color.GetGreenComponent(pixel);
B = Color.GetBlueComponent(pixel);
R = G = B = (int)(0.299 * R + 0.587 * G + 0.114 * B);
if (R < 128) {
m_imageArray[k] = 0;
} else {
m_imageArray[k] = 1;
}
}
if(m_dataWidth>width){
for(int p=width;p<m_dataWidth;p++,k++){
m_imageArray[k]=1;
}
}
}
}catch (Exception e) {
System.Console.WriteLine ("Converting to grayscale ex: " + e.Message);
}
}
Then get the byteArray of Monochrome image:
int length = 0;
for (int i = 0; i < m_imageArray.Length; i = i + 8) {
byte first = m_imageArray[i];
for (int j = 0; j < 7; j++) {
byte second = (byte) ((first << 1) | m_imageArray[i + j]);
first = second;
}
m_rawImage[length] = first;
length++;
}
And finally create the bitmap "by hand" using the following variables and placing them into a FileOutputStream to save the file:
private static int FILE_HEADER_SIZE = 14;
private static int INFO_HEADER_SIZE = 40;
// Bitmap file header
private byte[] bfType = { (byte) 'B', (byte) 'M' };
private int bfSize = 0;
private int bfReserved1 = 0;
private int bfReserved2 = 0;
private int bfOffBits = FILE_HEADER_SIZE + INFO_HEADER_SIZE + 8;
// Bitmap info header
private int biSize = INFO_HEADER_SIZE;
private int biWidth = 0;
private int biHeight = 0;
private int biPlanes = 1;
private int biBitCount = 1;
private int biCompression = 0;
private int biSizeImage = 0;
private int biXPelsPerMeter = 0x0;
private int biYPelsPerMeter = 0x0;
private int biClrUsed = 2;
private int biClrImportant = 2;
// Bitmap raw data
private byte[] bitmap;
// Scanlinsize;
int scanLineSize = 0;
// Color Pallette to be used for pixels.
private byte[] colorPalette = { 0, 0, 0, (byte) 255, (byte) 255,
(byte) 255, (byte) 255, (byte) 255 };
Bitmap bmpMonochrome = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmpMonochrome);
ColorMatrix ma = new ColorMatrix();
ma.setSaturation(0);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(ma));
canvas.drawBitmap(bmpSrc, 0, 0, paint);
Like so!
Source
I've searched for how to pixelate an image in android via code, the results are varied.
I've found libraries and tutorials on how to apply other effects found here: http://xjaphx.wordpress.com/learning/tutorials/
Can someone clear things up for me, what is the simplest way of pixelating an image on the fly in android
Also it would be handy if it was a function that I could how many rounds or how much I wanted the image pixelating.
Thank in advance.
The simplest way to pixelate the image would be to scale image down using "nearest neighbour" algorithm, and then scale up, using the same algorithm.
Filtering over the image trying to find an average takes much more time, but does not actually give any improvements in result quality, after all you do intentionally want your image distorted.
I have done this before in vb.net and its easily made into a function whose parameter can control how pixelated you want it.
The basic idea is to scan the image in section of blocks of X width and y height. for each block you find the average RGB value and set all those pixels to that color. the smaller the block size the less pixelated.
int avR,avB,avG; // store average of rgb
int pixel;
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y++ pixelationamount) {
avR = 0; avG = 0; avB =0;
for(int xx =x; xx <pixelationAmount;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <pixelationAmount;yy++){ // this is scanning the colors
pixel = src.getPixel(x, y);
avR += (int) (color.red(pixel);
avG+= (int) (color.green(pixel);
avB += (int) (color.blue(pixel);
}
}
avrR/= pixelationAmount^2; //divide all by the amount of samples taken to get an average
avrG/= pixelationAmount^2;
avrB/= pixelationAmount^2;
for(int xx =x; xx <pixelationAmount;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <pixelationAmount;yy++){ // this is going back over the block
bmOut.setPixel(xx, yy, Color.argb(255, avR, avG,avB)); //sets the block to the average color
}
}
}
}
sorry about the bad formatting (wrote it in notepad quickly) but thought it might give you a framework to make your own pixelate function
This is corrected of above algorithm that works:
Bitmap bmOut = Bitmap.createBitmap(OriginalBitmap.getWidth(),OriginalBitmap.getHeight(),OriginalBitmap.getConfig());
int pixelationAmount = 50; //you can change it!!
int width = OriginalBitmap.getWidth();
int height = OriginalBitmap.getHeight();
int avR,avB,avG; // store average of rgb
int pixel;
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y+= pixelationAmount) {
avR = 0; avG = 0; avB =0;
int bx = x + pixelationAmount;
int by = y + pixelationAmount;
if(by >= height) by = height;
if(bx >= width)bx = width;
for(int xx =x; xx < bx;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy < by;yy++){ // this is scanning the colors
pixel = OriginalBitmap.getPixel(xx, yy);
avR += (int) (Color.red(pixel));
avG+= (int) (Color.green(pixel));
avB += (int) (Color.blue(pixel));
}
}
avR/= pixelationAmount^2; //divide all by the amount of samples taken to get an average
avG/= pixelationAmount^2;
avB/= pixelationAmount^2;
for(int xx =x; xx < bx;xx++)// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <by;yy++){ // this is going back over the block
bmOut.setPixel(xx, yy, Color.argb(255, avR, avG,avB)); //sets the block to the average color
}
}
}
iv.setImageBitmap(bmOut);
anyway it was not what i was looking for
I have change previous algorithm completely and it really done something like mosaic filter!
the idea is to replace each block pixels with its below block pixels
use this function simply:
public void filter(){
Bitmap bmOut = Bitmap.createBitmap(OriginalBitmap.getWidth(),OriginalBitmap.getHeight(),OriginalBitmap.getConfig());
int pixelationAmount = 10;
Bitmap a = Bitmap.createBitmap(pixelationAmount,pixelationAmount,OriginalBitmap.getConfig());
Bitmap b = Bitmap.createBitmap(pixelationAmount,pixelationAmount,OriginalBitmap.getConfig());
int width = OriginalBitmap.getWidth();
int height = OriginalBitmap.getHeight();
int pixel;
int counter = 1;
int px = 0;int py = 0;int pbx=0;int pby=0;
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y+= pixelationAmount) {
int bx = x + pixelationAmount;
int by = y + pixelationAmount;
if(by >= height) by = height;
if(bx >= width)bx = width;
int xxx = -1;
int yyy = -1;
for(int xx =x; xx < bx;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
xxx++;
yyy = -1;
for(int yy= y; yy < by;yy++){ // this is scanning the colors
yyy++;
pixel = OriginalBitmap.getPixel(xx, yy);
if(counter == 1)
{
a.setPixel(xxx, yyy, pixel);
px = x;//previous x
py = y;//previous y
pbx = bx;
pby = by;
}
else
b.setPixel(xxx, yyy, pixel);
}
}
counter++;
if(counter == 3)
{
int xxxx = -1;
int yyyy = -1;
for(int xx =x; xx < bx;xx++)
{
xxxx++;
yyyy = -1;
for(int yy= y; yy <by;yy++){
yyyy++;
bmOut.setPixel(xx, yy, b.getPixel(xxxx, yyyy));
}
}
for(int xx =px; xx < pbx;xx++)
{
for(int yy= py; yy <pby;yy++){
bmOut.setPixel(xx, yy, a.getPixel(xxxx, yyyy)); //sets the block to the average color
}
}
counter = 1;
}
}
}
image_view.setImageBitmap(bmOut);
}
This is the code I used:
ImageFilter is the parent class:
public abstract class ImageFilter {
protected int [] pixels;
protected int width;
protected int height;
public ImageFilter (int [] _pixels, int _width,int _height){
setPixels(_pixels,_width,_height);
}
public void setPixels(int [] _pixels, int _width,int _height){
pixels = _pixels;
width = _width;
height = _height;
}
/**
* a weighted Euclidean distance in RGB space
* #param c1
* #param c2
* #return
*/
public double colorDistance(int c1, int c2)
{
int red1 = Color.red(c1);
int red2 = Color.red(c2);
int rmean = (red1 + red2) >> 1;
int r = red1 - red2;
int g = Color.green(c1) - Color.green(c2);
int b = Color.blue(c1) - Color.blue(c2);
return Math.sqrt((((512+rmean)*r*r)>>8) + 4*g*g + (((767-rmean)*b*b)>>8));
}
public abstract int[] procImage();
}
public class PixelateFilter extends ImageFilter {
int pixelSize;
int[] colors;
/**
* #param _pixels
* #param _width
* #param _height
*/
public PixelateFilter(int[] _pixels, int _width, int _height) {
this(_pixels, _width, _height, 10);
}
public PixelateFilter(int[] _pixels, int _width, int _height, int _pixelSize) {
this(_pixels, _width, _height, _pixelSize, null);
}
public PixelateFilter(int[] _pixels, int _width, int _height, int _pixelSize, int[] _colors) {
super(_pixels, _width, _height);
pixelSize = _pixelSize;
colors = _colors;
}
/* (non-Javadoc)
* #see imageProcessing.ImageFilter#procImage()
*/
#Override
public int[] procImage() {
for (int i = 0; i < width; i += pixelSize) {
for (int j = 0; j < height; j += pixelSize) {
int rectColor = getRectColor(i, j);
fillRectColor(rectColor, i, j);
}
}
return pixels;
}
private int getRectColor(int col, int row) {
int r = 0, g = 0, b = 0;
int sum = 0;
for (int x = col; x < col + pixelSize; x++) {
for (int y = row; y < row + pixelSize; y++) {
int index = x + y * width;
if (index < width * height) {
int color = pixels[x + y * width];
r += Color.red(color);
g += Color.green(color);
b += Color.blue(color);
}
}
}
sum = pixelSize * pixelSize;
int newColor = Color.rgb(r / sum, g / sum, b / sum);
if (colors != null)
newColor = getBestMatch(newColor);
return newColor;
}
private int getBestMatch(int color) {
double diff = Double.MAX_VALUE;
int res = color;
for (int c : colors) {
double currDiff = colorDistance(color, c);
if (currDiff < diff) {
diff = currDiff;
res = c;
}
}
return res;
}
private void fillRectColor(int color, int col, int row) {
for (int x = col; x < col + pixelSize; x++) {
for (int y = row; y < row + pixelSize; y++) {
int index = x + y * width;
if (x < width && y < height && index < width * height) {
pixels[x + y * width] = color;
}
}
}
}
public static final Bitmap changeToPixelate(Bitmap bitmap, int pixelSize, int [] colors) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int[] pixels = new int[width * height];
bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
PixelateFilter pixelateFilter = new PixelateFilter(pixels, width, height, pixelSize, colors);
int[] returnPixels = pixelateFilter.procImage();
Bitmap returnBitmap = Bitmap.createBitmap(returnPixels, width, height, Bitmap.Config.ARGB_8888);
return returnBitmap;
}
}
Here is how you use it:
int [] colors = new int [] { Color.BLACK,Color.WHITE,Color.BLUE,Color.CYAN,Color.RED};
final Bitmap bmOut = PixelateFilter.changeToPixelate(OriginalBitmap, pixelSize,colors);
Guys I have a solution to crate a bitmap from 5 different another ones. However, I want this solution to be faster. I could not find another easy and fast way to do same.
private void createImage() {
// Magic numbers from image files
int numberOfImages = 5;
int imgWidth = 125;
int imgHeight = 300;
int totalwidth = imgWidth * numberOfImages;
int totalheight = imgHeight;
img = Bitmap.createBitmap(totalwidth, totalheight, Bitmap.Config.ARGB_8888);
for (int i = 0; i < numberOfImages; i++) {
Bitmap imgFile = BitmapFactory.decodeResource(context.getResources(), context.getResources().getIdentifier(
"f" + i, "drawable", context.getPackageName()));
for (int x = 0; x < imgWidth; x++) {
for (int y = 0; y < imgHeight; y++) {
int targetX = x + (i * imgWidth);
int targetY = y;
int color = imgFile.getPixel(x, targetY);
img.setPixel(targetX, targetY, color);
}
}
}
img = Bitmap.createScaledBitmap(img, screenWidth, screenHeight, true);
}
You are mostly there. You've created a bitmap that is wide enough for them all.
What you then need to do is draw the bitmaps directly onto it one at a time, but the whole bitmap at once, not pixel by pixel.
You can do this using something call Canvas. Which aids in drawing things onto bitmaps.
img = Bitmap.createBitmap(totalwidth, totalheight, Bitmap.Config.ARGB_8888);
Canvas drawCanvas = new Canvas(img);
for (int i = 0; i < numberOfImages; i++) {
Bitmap imgFile = BitmapFactory.decodeResource(context.getResources(), context.getResources().getIdentifier(
"f" + i, "drawable", context.getPackageName()));
// Draw bitmap onto combo bitmap, at offset x, y.
drawCanvas.drawBitmap(imgFile, i * imgWidth, 0, null);
}
I imagine the Bitmap.getPixels() and Bitmap.setPixels() methods might help.
private void createImage() {
// Magic numbers from image files
int numberOfImages = 5;
int imgWidth = 125;
int imgHeight = 300;
int totalwidth = imgWidth * numberOfImages;
int totalheight = imgHeight;
img = Bitmap.createBitmap(totalwidth, totalheight, Bitmap.Config.ARGB_8888);
int buf[] = new int[totalwidth * totalheight];
for (int i = 0; i < numberOfImages; ++i) {
Bitmap imgFile = BitmapFactory.decodeResource(context.getResources(),
context.getResources().getIdentifier(
"f" + i, "drawable", context.getPackageName()));
imgFile.getPixels(buf, i*imgWidth, totalwidth, 0, 0, imgWidth, imgHeight);
}
img.setPixels(buf, 0, totalwidth, 0, 0, totalwidth, totalheight);
img = Bitmap.createScaledBitmap(img, screenWidth, screenHeight, true);
}
I have not tried it, but based on the documentation, I think it should work. I imagine it will hopefully be considerably faster since we do all the work with only 6 function calls, assuming that under the covers those functions do something much more clever than just looping over the array (such as direct memory copy).
The Doomsknight's answer seems correct to me but you should not do this kind of processes on the main thread for Android. Too many images might hit the 16ms barrier.
You can do this in background handler thread and update the UI Thread after finished.
HandlerThread cropperHandlerThread = new HandlerThread("background_cropper");
cropperHandlerThread.start();
// Do not call getLooper before start handler thread.
Handler cropperHandler = new Handler(cropperHandlerThread.getLooper());
cropperHandler.post(new Runnable() {
#Override
public void run() {
// Create Bitmap Here
MainActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
// Update ImageView here
}
});
}
});
i implement some code for water color effect on image in android but it was to slow(it's take more then 2 minute) now i try to implement this in JNI for batter speed ,
hear is my java code for
the inPixels is pixel of Bitmap .
protected int[] filterPixels( int width, int height, int[] inPixels )
{
int levels = 256;
int index = 0;
int[] rHistogram = new int[levels];
int[] gHistogram = new int[levels];
int[] bHistogram = new int[levels];
int[] rTotal = new int[levels];
int[] gTotal = new int[levels];
int[] bTotal = new int[levels];
int[] outPixels = new int[width * height];
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
for (int i = 0; i < levels; i++)
rHistogram[i] = gHistogram[i] = bHistogram[i] = rTotal[i] = gTotal[i] = bTotal[i] = 0;
for (int row = -range; row <= range; row++)
{
int iy = y+row;
int ioffset;
if (0 <= iy && iy < height)
{
ioffset = iy*width;
for (int col = -range; col <= range; col++)
{
int ix = x+col;
if (0 <= ix && ix < width) {
int rgb = inPixels[ioffset+ix];
int r = (rgb >> 16) & 0xff;
int g = (rgb >> 8) & 0xff;
int b = rgb & 0xff;
int ri = r*levels/256;
int gi = g*levels/256;
int bi = b*levels/256;
rTotal[ri] += r;
gTotal[gi] += g;
bTotal[bi] += b;
rHistogram[ri]++;
gHistogram[gi]++;
bHistogram[bi]++;
}
}
}
}
int r = 0, g = 0, b = 0;
for (int i = 1; i < levels; i++)
{
if (rHistogram[i] > rHistogram[r])
r = i;
if (gHistogram[i] > gHistogram[g])
g = i;
if (bHistogram[i] > bHistogram[b])
b = i;
}
r = rTotal[r] / rHistogram[r];
g = gTotal[g] / gHistogram[g];
b = bTotal[b] / bHistogram[b];
outPixels[index] = (inPixels[index] & 0xff000000) | ( r << 16 ) | ( g << 8 ) | b;
index++;
}
}
return outPixels;
}
**OUTPUT image **
and i try to convert this java code to c code but i don't what is the wrong ,
hear the code for C
void filterPixels( int width, int height, int inPixels[] )
{
int levels = 256;
int index = 0;
int rHistogram [levels];
int gHistogram [levels];
int bHistogram [levels];
int rTotal [levels];
int gTotal [levels];
int bTotal [levels];
int outPixels [width * height];
//Loop Variables
int y ;
int x ;
int i ;
int row ;
int col ;
int j ;
int range = 5 ;
for ( y = 0; y < height; y++)
{
for ( x = 0; x < width; x++)
{
for ( i = 0; i < levels; i++)
rHistogram[i] = gHistogram[i] = bHistogram[i] = rTotal[i] = gTotal[i] = bTotal[i] = 0;
for ( row = -range; row <= range; row++)
{
int iy = y+row;
int ioffset;
if (0 <= iy && iy < height)
{
ioffset = iy*width;
for ( col = -range; col <= range; col++)
{
int ix = x+col;
if (0 <= ix && ix < width) {
int rgb = inPixels[ioffset+ix];
int r = (rgb >> 16) & 0xff;
int g = (rgb >> 8) & 0xff;
int b = rgb & 0xff;
int ri = r*levels/256;
int gi = g*levels/256;
int bi = b*levels/256;
rTotal[ri] += r;
gTotal[gi] += g;
bTotal[bi] += b;
rHistogram[ri]++;
gHistogram[gi]++;
bHistogram[bi]++;
}
}
}
}
int r = 0, g = 0, b = 0;
for ( j = 1; j < levels; j++)
{
if (rHistogram[j] > rHistogram[r])
r = j;
if (gHistogram[j] > gHistogram[g])
g = j;
if (bHistogram[j] > bHistogram[b])
b = j;
}
r = rTotal[r] / rHistogram[r];
g = gTotal[g] / gHistogram[g];
b = bTotal[b] / bHistogram[b];
outPixels[index] = (inPixels[index] & 0xff000000) | ( r << 16 ) | ( g << 8 ) | b;
index++;
}
}
}
i check the pixel value of java code and c code both are same(for same image)
code for call native function from my android activity .
int[] pix = new int[oraginal.getWidth() * oraginal.getHeight()];
Bitmap bitmap = oraginal.copy(oraginal.getConfig(), true);
bitmap.getPixels(pix, 0, bitmap.getWidth(), 0, 0,bitmap.getWidth(), bitmap.getHeight());
filterPixelsJNI(bitmap.getWidth(), bitmap.getHeight(), pix);
bitmap.setPixels(pix, 0, bitmap.getWidth(), 0, 0,bitmap.getWidth(), bitmap.getHeight());
myView.setImageBitmap(bitmap);
this is my first try for JNI so plz help me in this .
UPDATE
public native void filterPixelsJNI( int width, int height, int inPixels[] );
JNI
JNIEXPORT void JNICALL Java_com_testndk_HelloWorldActivity_filterPixelsJNI (JNIEnv * env, jobject obj , jint width,jint height,jint inPixels[]){
filterPixels( width, height, inPixels);
}
filterPixels method witch is call from c code .
There are several problems with your JNI code. The algorithmic part is probably correct, but you're not dealing with the Java array to C array conversion correctly.
First of all, the last argument of Java_com_testndk_HelloWorldActivity_filterPixelsJNI should be of type jintArray, and not jint []. This is how you pass a Java array to C code.
Once you get this array, you can't process it directly, you'll have to convert it to a C array:
JNIEXPORT void JNICALL Java_com_testndk_HelloWorldActivity_filterPixelsJNI (JNIEnv * env, jobject obj , jint width, jint height, jintArray inPixels) {
int *c_inPixels = (*env)->GetIntArrayElements(env, inPixels, NULL);
filterPixels( width, height, c_inPixels);
// passing 0 as the last argument should copy native array to Java array
(*env)->ReleaseIntArrayElements(env, inPixels, c_inPixels, 0);
}
I advise you to look at the JNI documentation, which explains how to deal with arrays: http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/functions.html
Note that there are now easier ways of processing Java Bitmap objects using android NDK. See an other of my answers here for details.