Develop Reference

How can we enhance apply Brightness Effect with custom filter?

I am trying to add custom filter and add brightness and contrast, but it takes to much time.
How can i decrease these times?
Can we use other way or add filter over filter?
//main class
private ImageView imgMain;
imgMain = (ImageView) findViewById(R.id.effect_main);
imgMain.setColorFilter(filterClass.setFilter(2));
Bitmap bitmap = ((BitmapDrawable)imgMain.getDrawable()).getBitmap();
bitmap =imgFilter.applyBrightnessEffect(bitmap , 150);
imgMain.setImageBitmap(bitmap);
for custom filter
//filter methords
public ColorMatrixColorFilter catNightFilter() {
float[] matrix = {
89, 61, -5, 0, 0, //red
77, 67, 24, 0, 0, //green
-57, -13, 81, 0, 0, //blue
0, 0, 0, 0, 0 //alpha
};
ColorMatrix cm = new ColorMatrix(matrix);``
return new ColorMatrixColorFilter(cm);
}
This Brightness code takes to much time it convert each pixel.
// scan through all pixels
//britness methord
public Bitmap applyBrightnessEffect(Bitmap src, int value) {
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
for(int x = 0; x < width; ++x) {
for(int y = 0; y < height; ++y) {
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
R = Color.red(pixel);
G = Color.green(pixel);
B = Color.blue(pixel);
// increase/decrease each channel
R += value;
if(R > 255) { R = 255; }
else if(R < 0) { R = 0; }
G += value;
if(G > 255) { G = 255; }
else if(G < 0) { G = 0; }
B += value;
if(B > 255) { B = 255; }
else if(B < 0) { B = 0; }
// apply new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
// return final image
return bmOut;
}

How can i implement seek bar to change contrast

I am trying to implement a seek bar to change contrast of an image in android. Anyone Help me to Implement this please.There is any other options for image processing ?
Does anyone know the solution Please help me
Thanks in Advance.
CODE:
public class MainActivity extends ActionBarActivity {
ImageView imViewAndroid;
private SeekBar seekbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
seekbar = (SeekBar) findViewById(R.id.seekbar);
imViewAndroid = (ImageView) findViewById(R.id.imViewAndroid);
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
imViewAndroid.setImageBitmap(takeContrast(BitmapFactory.decodeResource(getResources(), R.drawable.dicom), 100));
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
public Bitmap takeContrast(Bitmap src, double value) {
// src image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap with original size
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
// get contrast value
double contrast = Math.pow((100 + value) / 100, 2);
// scan through all pixels
for(int x = 0; x < width; ++x) {
for(int y = 0; y < height; ++y) {
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
// apply filter contrast for every channel R, G, B
R = Color.red(pixel);
R = (int)(((((R / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(R < 0) { R = 0; }
else if(R > 255) { R = 255; }
G = Color.red(pixel);
G = (int)(((((G / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(G < 0) { G = 0; }
else if(G > 255) { G = 255; }
B = Color.red(pixel);
B = (int)(((((B / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(B < 0) { B = 0; }
else if(B > 255) { B = 255; }
// set new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
// return final image
return bmOut;
}

You call the function to change contrast in a wrong place it should be here
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
// call the method here, default progress is <0, 100>
}
You use very slow function to change the contrast. There are plenty answers already on StackOverflow, have a look at this answer. Search before you ask.
Look at this full implementation on my github.

The above code takes too much time for processing image. If you use my code processing of image takes very less time.
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
contrastAndBrightnessControler(bitmap,seekbar.getProgress()/10,0.7)
}
public static Bitmap contrastAndBrightnessControler(Bitmap bitmap, float contrast, float brightness)
{
ColorMatrix cmatrix = new ColorMatrix(new float[]
{
contrast, 0, 0, 0, brightness,
0, contrast, 0, 0, brightness,
0, 0, contrast, 0, brightness,
0, 0, 0, 1, 0
});
Bitmap ret =Bitmap.createBitmap(bitmap.getWidth(),bitmap.getHeight(), bitmap.getConfig());
Canvas canvas = new Canvas(ret);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(cmatrix));
canvas.drawBitmap(bitmap, 0, 0, paint);
return ret;
}

How to adjust image brightness in Android with OpenCV?

I created an example image with brightness adjusted in Android. I used Bitmap to adjust the brightness but it takes a very long time to run. Instead, I want to set the image brightness in Android using OpenCV.
This is my example code, but it only changes the colour of the image:
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);
[Update]
I try add code, but it error
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.a001);
int width = bmp.getWidth();
int height = bmp.getHeight();
Mat mRgba = new Mat(width, height, CvType.CV_8UC1);
Utils.bitmapToMat(bmp, mRgba);
Mat mRay = new Mat();
Imgproc.cvtColor(mRgba, mRay, Imgproc.COLOR_BGRA2RGB, 4);
/*
* Use Adaptive Thresholding on the grayscaled Mats crop -> threshed Mat
* src, Mat dst, double maxValue, int adaptiveMethod, int thresholdType,
* int blockSize, double C
*/
Imgproc.adaptiveThreshold(threshed, threshed, 255,
Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, Imgproc.THRESH_BINARY_INV, 15, 8);
Utils.matToBitmap(mRay, bmp);
mImageview_01.setImageBitmap(bmp);
[Error]
CvException [org.opencv.core.CvException: /home/reports/ci/slave_desktop/50-SDK/opencv/modules/imgproc/src/thresh.cpp:796: error: (-215) src.type() == CV_8UC1 in function void cv::adaptiveThreshold(cv::InputArray, cv::OutputArray, double, int, int, int, double)
Pls view examples of what I'm trying to do here.

There is many fast and easy ways to adjust a bitmap brightness, such as ColorMatrix or RenderScript. But if you still considered to use OpenCV that's the way :
private Bitmap changeBrightness(Bitmap bmp, int value){
Mat src = new Mat(bmap.getHeight(),bmap.getWidth(), CvType.CV_8UC1);
Utils.bitmapToMat(bmap,src);
src.convertTo(src,-1,1,value);
Bitmap result = Bitmap.createBitmap(src.cols(),src.rows(), Bitmap.Config.ARGB_8888);
Utils.matToBitmap(src,result);
return result;
}

check the example given at Increase/Decrease Brightness of Image
pls see this
int brightness;
SeekBar seekBarBrightness=(SeekBar)findViewById(R.id.seekBar1);
seekBarBrightness.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
#Override
public void onStopTrackingTouch(SeekBar arg0) {
}
#Override
public void onStartTrackingTouch(SeekBar arg0) {
}
#Override
public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) {
Bitmap newBitMap = doBrightness(bitMap,progress);
imageView.setImageBitmap(newBitMap);
}
});
public static Bitmap doBrightness(Bitmap src, int value)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
// scan through all pixels
for (int x = 0; x < width; ++x)
{
for (int y = 0; y < height; ++y)
{
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
R = Color.red(pixel);
G = Color.green(pixel);
B = Color.blue(pixel);
// increase/decrease each channel
R += value;
if (R > 255)
{
R = 255;
} else if (R < 0)
{
R = 0;
}
G += value;
if (G > 255)
{
G = 255;
} else if (G < 0)
{
G = 0;
}
B += value;
if (B > 255)
{
B = 255;
} else if (B < 0)
{
B = 0;
}
// apply new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
// return final image
return bmOut;
}

How to programmatically change contrast of a bitmap in android?

I want to programmatically change the contrast of bitmap. Till now I have tried this.
private Bitmap adjustedContrast(Bitmap src, double value)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// color information
int A, R, G, B;
int pixel;
// get contrast value
double contrast = Math.pow((100 + value) / 100, 2);
// scan through all pixels
for(int x = 0; x < width; ++x) {
for(int y = 0; y < height; ++y) {
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
// apply filter contrast for every channel R, G, B
R = Color.red(pixel);
R = (int)(((((R / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(R < 0) { R = 0; }
else if(R > 255) { R = 255; }
G = Color.green(pixel);
G = (int)(((((G / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(G < 0) { G = 0; }
else if(G > 255) { G = 255; }
B = Color.blue(pixel);
B = (int)(((((B / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(B < 0) { B = 0; }
else if(B > 255) { B = 255; }
// set new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
return bmOut;
}
But this does not work as expected. Please help me in this or provide any other solution to achieve this. Thanks in advance.

Here is complete method:
/**
*
* #param bmp input bitmap
* #param contrast 0..10 1 is default
* #param brightness -255..255 0 is default
* #return new bitmap
*/
public static Bitmap changeBitmapContrastBrightness(Bitmap bmp, float contrast, float brightness)
{
ColorMatrix cm = new ColorMatrix(new float[]
{
contrast, 0, 0, 0, brightness,
0, contrast, 0, 0, brightness,
0, 0, contrast, 0, brightness,
0, 0, 0, 1, 0
});
Bitmap ret = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());
Canvas canvas = new Canvas(ret);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(bmp, 0, 0, paint);
return ret;
}

Try this. Your code didn't work because you create only a mutable bitmap and didn't copy the image of source bitmap to the mutable one if i'm not mistaken.
Hope It helps :)
private Bitmap adjustedContrast(Bitmap src, double value)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
// create output bitmap
// create a mutable empty bitmap
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
// create a canvas so that we can draw the bmOut Bitmap from source bitmap
Canvas c = new Canvas();
c.setBitmap(bmOut);
// draw bitmap to bmOut from src bitmap so we can modify it
c.drawBitmap(src, 0, 0, new Paint(Color.BLACK));
// color information
int A, R, G, B;
int pixel;
// get contrast value
double contrast = Math.pow((100 + value) / 100, 2);
// scan through all pixels
for(int x = 0; x < width; ++x) {
for(int y = 0; y < height; ++y) {
// get pixel color
pixel = src.getPixel(x, y);
A = Color.alpha(pixel);
// apply filter contrast for every channel R, G, B
R = Color.red(pixel);
R = (int)(((((R / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(R < 0) { R = 0; }
else if(R > 255) { R = 255; }
G = Color.green(pixel);
G = (int)(((((G / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(G < 0) { G = 0; }
else if(G > 255) { G = 255; }
B = Color.blue(pixel);
B = (int)(((((B / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
if(B < 0) { B = 0; }
else if(B > 255) { B = 255; }
// set new pixel color to output bitmap
bmOut.setPixel(x, y, Color.argb(A, R, G, B));
}
}
return bmOut;
}

We can use seek bar to adjust contrast.
MainActivity.java:
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Paint;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
ImageView imageView;
SeekBar seekbar;
TextView textView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = (ImageView) findViewById(R.id.image);
textView = (TextView) findViewById(R.id.label);
seekbar = (SeekBar) findViewById(R.id.seekbar);
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
imageView.setImageBitmap(changeBitmapContrastBrightness(BitmapFactory.decodeResource(getResources(), R.drawable.lhota), (float) progress / 100f, 1));
textView.setText("Contrast: "+(float) progress / 100f);
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {}
});
seekbar.setMax(200);
seekbar.setProgress(100);
}
public static Bitmap changeBitmapContrastBrightness(Bitmap bmp, float contrast, float brightness) {
ColorMatrix cm = new ColorMatrix(new float[]
{
contrast, 0, 0, 0, brightness,
0, contrast, 0, 0, brightness,
0, 0, contrast, 0, brightness,
0, 0, 0, 1, 0
});
Bitmap ret = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());
Canvas canvas = new Canvas(ret);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawBitmap(bmp, 0, 0, paint);
return ret;
}
}
activity_main.java:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/label"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="8dp"
android:textAppearance="#android:style/TextAppearance.Holo.Medium" />
<SeekBar
android:id="#+id/seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>

Here is a Renderscript implementation (from the Gradle Example Projects)
ip.rsh
#pragma version(1)
#pragma rs java_package_name(your.app.package)
contrast.rs
#include "ip.rsh"
static float brightM = 0.f;
static float brightC = 0.f;
void setBright(float v) {
brightM = pow(2.f, v / 100.f);
brightC = 127.f - brightM * 127.f;
}
void contrast(const uchar4 *in, uchar4 *out)
{
#if 0
out->r = rsClamp((int)(brightM * in->r + brightC), 0, 255);
out->g = rsClamp((int)(brightM * in->g + brightC), 0, 255);
out->b = rsClamp((int)(brightM * in->b + brightC), 0, 255);
#else
float3 v = convert_float3(in->rgb) * brightM + brightC;
out->rgb = convert_uchar3(clamp(v, 0.f, 255.f));
#endif
}
Java
private Bitmap changeBrightness(Bitmap original RenderScript rs) {
Allocation input = Allocation.createFromBitmap(rs, original);
final Allocation output = Allocation.createTyped(rs, input.getType());
ScriptC_contrast mScript = new ScriptC_contrast(rs);
mScript.invoke_setBright(50.f);
mScript.forEach_contrast(input, output);
output.copyTo(original);
return original;
}

Assumption - ImageView is used to display the bitmap
I did a more enhancement in the Ruslan's answer
Instead of replacing bitmap every time (which makes it slow if you are using seek bar) we can work on the Color Filter of the ImageView.
float contrast;
float brightness = 0;
ImageView imageView;
// SeekBar ranges from 0 to 90
// contrast ranges from 1 to 10
mSeekBarContrast.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
contrast = (float) (i + 10) / 10;
// Changing the contrast of the bitmap
imageView.setColorFilter(getContrastBrightnessFilter(contrast,brightness));
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
ColorMatrixColorFilter getContrastBrightnessFilter(float contrast, float brightness) {
ColorMatrix cm = new ColorMatrix(new float[]
{
contrast, 0, 0, 0, brightness,
0, contrast, 0, 0, brightness,
0, 0, contrast, 0, brightness,
0, 0, 0, 1, 0
});
return new ColorMatrixColorFilter(cm);
}
P.S - Brightness can also be changed along with contrast using this method

I just had the same problem and ended up using the Color Matrix that Ruslan Yanchyshyn describes. I needed to automatically adjust brightness depending on the image, so I used BoofCV to create a histogram from a scaled version of the image - It took way to long to process the whole image. Then I analyzed the histogram - looked at what was the darkest and brightest colors and then created a color matrix which transforms the colors so the darkest colors are 0 and the brightest colors are 255. In this way the new image uses the whole spectrum from dark/black to light/white now.
Ended up writing a small post on how I did it on our company blog here if anyone are interested. http://appdictive.dk/blog/projects/2016/07/26/levels_with_color_matrix/

Maybe you can try this one:
http://xjaphx.wordpress.com/2011/06/21/image-processing-contrast-image-on-the-fly/
Hope that helps! :)

http://android.okhelp.cz/bitmap-set-contrast-and-brightness-android/
have a look at this ,this might solve your problem

Replace black color in bitmap with red

How can I replace the black color in a bitmap with red (or any other color) programmatically in Android (ignoring transparency)? I can replace the white color in the bitmap with a color already but it somehow does not work with black.
Thanks for help.

Get all the pixels in the bitmap using this:
int [] allpixels = new int [myBitmap.getHeight() * myBitmap.getWidth()];
myBitmap.getPixels(allpixels, 0, myBitmap.getWidth(), 0, 0, myBitmap.getWidth(), myBitmap.getHeight());
for(int i = 0; i < allpixels.length; i++)
{
if(allpixels[i] == Color.BLACK)
{
allpixels[i] = Color.RED;
}
}
myBitmap.setPixels(allpixels,0,myBitmap.getWidth(),0, 0, myBitmap.getWidth(),myBitmap.getHeight());

This works for me
public Bitmap replaceColor(Bitmap src,int fromColor, int targetColor) {
if(src == null) {
return null;
}
// Source image size
int width = src.getWidth();
int height = src.getHeight();
int[] pixels = new int[width * height];
//get pixels
src.getPixels(pixels, 0, width, 0, 0, width, height);
for(int x = 0; x < pixels.length; ++x) {
pixels[x] = (pixels[x] == fromColor) ? targetColor : pixels[x];
}
// create result bitmap output
Bitmap result = Bitmap.createBitmap(width, height, src.getConfig());
//set pixels
result.setPixels(pixels, 0, width, 0, 0, width, height);
return result;
}
Now set your bit map
replaceColor(bitmapImg,Color.BLACK,Color.GRAY )
For better view please check this Link

#nids : Have you tried replacing your Color to Color.TRANSPARENT ? That should work...