Develop Reference

Create HSV histogram with RenderScript

I have to create a HSV Histogram from a ARGB array using RenderScript in Android. This is the first time i am using RenderScript and i am not sure if i made a mistake because the performance is not so good. Creating a HSV histogram from an 1920x1080 bitmap takes between 100 and 150 ms.
The RenderScript code:
#pragma version(1)
#pragma rs java_package_name(com.test.renderscript)
#pragma rs_fp_relaxed
uchar3 bins;
rs_allocation histogramAllocation;
void __attribute__((kernel)) process(uchar4 in) {
float r = in.r / 255.0;
float g = in.g / 255.0;
float b = in.b / 255.0;
// convert rgb to hsv
float minRGB = min( r, min( g, b ) );
float maxRGB = max( r, max( g, b ) );
float deltaRGB = maxRGB - minRGB;
float h = 0.0;
float s = maxRGB == 0 ? 0 : (maxRGB - minRGB) / maxRGB;
float v = maxRGB;
if (deltaRGB != 0) {
if (r == maxRGB) {
h = (g - b) / deltaRGB;
}
else {
if (g == maxRGB) {
h = 2 + (b - r) / deltaRGB;
}
else {
h = 4 + (r - g) / deltaRGB;
}
}
h *= 60;
if (h < 0) { h += 360; }
if (h == 360) { h = 0; }
}
// quantize hsv
uint qh = h / (360.0 / bins.s0);
uint qs = (s * 100) / (101.0 / bins.s1);
uint qv = (v * 100) / (101.0 / bins.s2);
// calculate bin index and update the count at that index
// (v * bin size H * bin size S) + (s * bin size H) + h;
uint binIndex = (qv * bins.s0 * bins.s1) + (qs * bins.s0) + qh;
uint count = rsGetElementAt_uint(histogramAllocation, binIndex);
rsSetElementAt_uint(histogramAllocation, (count + 1), binIndex);
}
void init() {
uint histogramSize = bins.s0 * bins.s1 * bins.s2;
for (int i=0; i < histogramSize; i++) {
rsSetElementAt_uint(histogramAllocation, 0, i);
}
}
The Kotlin code:
class RsCreateHsvHistogram {
fun execute(rs: RenderScript, src: ByteArray, bins: HsvHistogram.Bins = HsvHistogram.Bins()): HsvHistogram {
val start = SystemClock.elapsedRealtimeNanos()
val histogramSize = bins.h * bins.s * bins.v
// create input allocation
val typeIn = Type.Builder(rs, Element.U8_4(rs))
.setX(src.size / 4)
.create()
val allocIn = Allocation.createTyped(rs, typeIn)
allocIn.copyFrom(src)
// create output allocation -> the histogram allocation
val typeOut = Type.Builder(rs, Element.I32(rs))
.setX(histogramSize)
.create()
val allocOut = Allocation.createTyped(rs, typeOut)
// run the render script
val script = ScriptC_create_hsv_histogram(rs)
script._bins = Short3(bins.h, bins.s, bins.v)
script._histogramAllocation = allocOut
script.forEach_process(allocIn)
// copy output allocation to histogram array
val histogramData = IntArray(histogramSize)
allocOut.copyTo(histogramData)
val stop = SystemClock.elapsedRealtimeNanos()
Timber.e("duration => ${(stop-start) / 1000000.0} ms")
return HsvHistogram(histogramData, bins)
}
}
I hope you can help me improve the performance. Do you think HSV histogram creation can be done in about 20ms? Is this realistic?

I want to create a +score system

So I created a game where u can move your character and u need to pass lines with that character, but I have 1 problem. When the first line reaches bottom of my screen only then the score starts counting. I want to make so that when my character passes the lines gap the score would +1. What should I do?
EDIT: Also the score counts when last line reaches bottom!
if (obstacles.get(obstacles.size()-1).getRectangle().top >= Constants.SCREEN_HEIGHT ){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(0, new Obstacle(obstacleHeight, color, xStart, obstacles.get(0).getRectangle().top - obstacleHeight - obstacleGap, playerGap));
obstacles.remove(obstacles.size()-1);
score++;
}
}
public void draw(Canvas canvas){
for(Obstacle ob : obstacles)
ob.draw(canvas);
Paint paint = new Paint();
paint.setTextSize(100);
paint.setColor(Color.GREEN);
canvas.drawText("" + score, 50, 100 + paint.descent()- paint.descent(), paint);
EDIT:
int currY = -5*Constants.SCREEN_HEIGHT/4, rect;
while(currY < 0){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(new Obstacle(obstacleHeight, color, xStart, currY, playerGap));
currY += obstacleHeight + obstacleGap;
}
if (obstacles.get(obstacles.size() - 1).getRectangle().top >= currY) {
score++;
}
EDIT2:
private void populateObatacles(){
int currY = -5*Constants.SCREEN_HEIGHT/4;
while(currY < 0){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(new Obstacle(obstacleHeight, color, xStart, currY, playerGap));
currY += obstacleHeight + obstacleGap;
}
}
EDIT3:
if (obstacles.get(lastLineScored-1).getRectangle().top >= currY) {
score++;
lastLineScored--;
}
if (obstacles.get(obstacles.size()-1).getRectangle().top >= Constants.SCREEN_HEIGHT ){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(0, new Obstacle(obstacleHeight, color, xStart, obstacles.get(0).getRectangle().top - obstacleHeight - obstacleGap, playerGap));
obstacles.remove(obstacles.size()-1);
lastLineScored++;
}
}
}
public void draw(Canvas canvas){
for(Obstacle ob : obstacles)
ob.draw(canvas);
Paint paint = new Paint();
paint.setTextSize(100);
paint.setColor(Color.GREEN);
canvas.drawText("" + score , 50, 100 + paint.descent()- paint.descent (), paint);
EDIT4:
Obstacle manager http://pastebin.com/6E77QtHj
Obstacle http://pastebin.com/p33mPrat

Change your test. Instead of checking whether the top of the line is greater than SCREEN_HEIGHT, check whether it is greater than the character's Y coordinate. Also, you need to check against each
if (obstacles.get(obstacles.size()-1).getRectangle().top >= /** character Y coordinate */) {
score++;
}
if (obstacles.get(obstacles.size()-1).getRectangle().top >= Constants.SCREEN_HEIGHT ){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(0, new Obstacle(obstacleHeight, color, xStart, obstacles.get(0).getRectangle().top - obstacleHeight - obstacleGap, playerGap));
obstacles.remove(obstacles.size()-1);
}
EDIT: You need to keep track of which lines are already past the character and only up the score when a new line goes past. You'll need to keep an index of which lines have already been scored. So create a field to keep that index; let's call it lastScoredLine. It should be initialized to obstacles.size(). You'll have to adjust that field whenever a line falls off the screen.
if (obstacles.get(lastLineScored-1).getRectangle().top >= /** character Y coordinate */) {
score++;
lastLineScored--;
}
if (obstacles.get(obstacles.size()-1).getRectangle().top >= Constants.SCREEN_HEIGHT ){
int xStart = (int) (Math.random()*(Constants.SCREEN_WIDTH- playerGap));
obstacles.add(0, new Obstacle(obstacleHeight, color, xStart, obstacles.get(0).getRectangle().top - obstacleHeight - obstacleGap, playerGap));
obstacles.remove(obstacles.size()-1);
lastLineScored++;
}

Camera2 API Set Custom White Balance & Temperature Color

I'm trying to set a custom value for the White Balance & temperature color in my camera app. I'm using camera2 API and I'm trying different ways to set this value. I found a method from a excel file to get the right RGB Temperature matrix [Red,Green,Blue] from the White Balance Value between 100 and 100.000.
I attached this method to a Seekbar and its working fine, my problem appear when I try to focus something white, then it becomes pink. Any kind of light looks like a pink torch in the screen.
I'm setting the values in this way:
mPreviewRequestBuilder.set(CaptureRequest.COLOR_CORRECTION_MODE, CaptureRequest.COLOR_CORRECTION_MODE_TRANSFORM_MATRIX);
RggbChannelVector rggb = getTemperatureVector(seekBackSelectedTemperature);
mPreviewRequestBuilder.set(CaptureRequest.COLOR_CORRECTION_GAINS, myRggbChannelVector);
In other way, my method to get the matrix is this one:
public static RggbChannelVector getTemperatureVector (int WhiteBalanceValue){
float InsertTemperature = WhiteBalanceValue;
float temperature = InsertTemperature / 100;
float red;
float green;
float blue;
//Calculate red
if (temperature <= 66)
red = 255;
else {
red = temperature - 60;
red = (float) (329.698727446 * (Math.pow((double) red, -0.1332047592)));
if (red < 0)
red = 0;
if (red > 255)
red = 255;
}
//Calculate green
if (temperature <= 66) {
green = temperature;
green = (float) (99.4708025861 * Math.log(green) - 161.1195681661);
if (green < 0)
green = 0;
if (green > 255)
green = 255;
} else
green = temperature - 60;
green = (float) (288.1221695283 * (Math.pow((double) red, -0.0755148492)));
if (green < 0)
green = 0;
if (green > 255)
green = 255;
//calculate blue
if (temperature >= 66)
blue = 255;
else if (temperature <= 19)
blue = 0;
else {
blue = temperature - 10;
blue = (float) (138.5177312231 * Math.log(blue) - 305.0447927307);
if (blue < 0)
blue = 0;
if (blue > 255)
blue = 255;
}
RggbChannelVector finalTemperatureValue = new RggbChannelVector(red/255,(green/255)/2,(green/255)/2,blue/255);
return finalTemperatureValue;
}
Maybe it's because the method of my CaptureRequest is not correct, but I don't find a way to fix it.

It worked after change the template to Still_capture or Manual Template and use the next method:
captureBuilder.set(CaptureRequest.CONTROL_AWB_MODE, CaptureRequest.CONTROL_AWB_MODE_OFF);
// adjust color correction using seekbar's params
captureBuilder.set(CaptureRequest.COLOR_CORRECTION_MODE, CaptureRequest.COLOR_CORRECTION_MODE_TRANSFORM_MATRIX);
captureBuilder.set(CaptureRequest.COLOR_CORRECTION_GAINS, CameraCapabilities.colorTemperature(Integer.parseInt(awbMode)));
public static RggbChannelVector colorTemperature(int whiteBalance) {
float temperature = whiteBalance / 100;
float red;
float green;
float blue;
//Calculate red
if (temperature <= 66)
red = 255;
else {
red = temperature - 60;
red = (float) (329.698727446 * (Math.pow((double) red, -0.1332047592)));
if (red < 0)
red = 0;
if (red > 255)
red = 255;
}
//Calculate green
if (temperature <= 66) {
green = temperature;
green = (float) (99.4708025861 * Math.log(green) - 161.1195681661);
if (green < 0)
green = 0;
if (green > 255)
green = 255;
} else {
green = temperature - 60;
green = (float) (288.1221695283 * (Math.pow((double) green, -0.0755148492)));
if (green < 0)
green = 0;
if (green > 255)
green = 255;
}
//calculate blue
if (temperature >= 66)
blue = 255;
else if (temperature <= 19)
blue = 0;
else {
blue = temperature - 10;
blue = (float) (138.5177312231 * Math.log(blue) - 305.0447927307);
if (blue < 0)
blue = 0;
if (blue > 255)
blue = 255;
}
Log.v(TAG, "red=" + red + ", green=" + green + ", blue=" + blue);
return new RggbChannelVector((red / 255) * 2, (green / 255), (green / 255), (blue / 255) * 2);
}

Another possible and more simpler solution; factor must be between 0 and 100:
private static RggbChannelVector computeTemperature(final int factor)
{
return new RggbChannelVector(0.635f + (0.0208333f * factor), 1.0f, 1.0f, 3.7420394f + (-0.0287829f * factor));
}

Android Bitmap save without transparent area

I want to save bitmap without transparent area.
Bitmap has large transparent pixel.
So i want to remove that
How can i do this?
I cant add picture so explain with symbols.
I dont want to crop function.
I hope use filter
┌────────────────────────┐
│ transparent area
│ ┌────────┐
│ crop this
└────────┘
└────────────────────────┘

To find the non-transparent area of your bitmap, iterate across the bitmap in x and y and find the min and max of the non-transparent region. Then crop the bitmap to those co-ordinates.
Bitmap CropBitmapTransparency(Bitmap sourceBitmap)
{
int minX = sourceBitmap.getWidth();
int minY = sourceBitmap.getHeight();
int maxX = -1;
int maxY = -1;
for(int y = 0; y < sourceBitmap.getHeight(); y++)
{
for(int x = 0; x < sourceBitmap.getWidth(); x++)
{
int alpha = (sourceBitmap.getPixel(x, y) >> 24) & 255;
if(alpha > 0) // pixel is not 100% transparent
{
if(x < minX)
minX = x;
if(x > maxX)
maxX = x;
if(y < minY)
minY = y;
if(y > maxY)
maxY = y;
}
}
}
if((maxX < minX) || (maxY < minY))
return null; // Bitmap is entirely transparent
// crop bitmap to non-transparent area and return:
return Bitmap.createBitmap(sourceBitmap, minX, minY, (maxX - minX) + 1, (maxY - minY) + 1);
}

Crop transparent border with this github.
public static Bitmap crop(Bitmap bitmap) {
int height = bitmap.getHeight();
int width = bitmap.getWidth();
int[] empty = new int[width];
int[] buffer = new int[width];
Arrays.fill(empty, 0);
int top = 0;
int left = 0;
int bottom = height;
int right = width;
for (int y = 0; y < height; y++) {
bitmap.getPixels(buffer, 0, width, 0, y, width, 1);
if (!Arrays.equals(empty, buffer)) {
top = y;
break;
}
}
for (int y = height - 1; y > top; y--) {
bitmap.getPixels(buffer, 0, width, 0, y, width, 1);
if (!Arrays.equals(empty, buffer)) {
bottom = y;
break;
}
}
empty = new int[height];
buffer = new int[height];
Arrays.fill(empty, 0);
for (int x = 0; x < width; x++) {
bitmap.getPixels(buffer, 0, 1, x, 0, 1, height);
if (!Arrays.equals(empty, buffer)) {
left = x;
break;
}
}
for (int x = width - 1; x > left; x--) {
bitmap.getPixels(buffer, 0, 1, x, 0, 1, height);
if (!Arrays.equals(empty, buffer)) {
right = x;
break;
}
}
return Bitmap.createBitmap(bitmap, left, top, right - left + 1, bottom - top + 1);
}

I took #Alvaro Menezes's answer and improved it as a Kotlin extension function. I tweaked it a bit, changed some variable names for better readability and it adds more fixes to the issue mentioned by #Ahamadullah Saikat that throws an IllegalArgumentException
Note that reading pixels by line improve a lot the performances against reading this independently as the accepted answer suggest.
/**
* Trims a bitmap borders of a given color.
*
*/
fun Bitmap.trim(#ColorInt color: Int = Color.TRANSPARENT): Bitmap {
var top = height
var bottom = 0
var right = width
var left = 0
var colored = IntArray(width, { color })
var buffer = IntArray(width)
for (y in bottom until top) {
getPixels(buffer, 0, width, 0, y, width, 1)
if (!Arrays.equals(colored, buffer)) {
bottom = y
break
}
}
for (y in top - 1 downTo bottom) {
getPixels(buffer, 0, width, 0, y, width, 1)
if (!Arrays.equals(colored, buffer)) {
top = y
break
}
}
val heightRemaining = top - bottom
colored = IntArray(heightRemaining, { color })
buffer = IntArray(heightRemaining)
for (x in left until right) {
getPixels(buffer, 0, 1, x, bottom, 1, heightRemaining)
if (!Arrays.equals(colored, buffer)) {
left = x
break
}
}
for (x in right - 1 downTo left) {
getPixels(buffer, 0, 1, x, bottom, 1, heightRemaining)
if (!Arrays.equals(colored, buffer)) {
right = x
break
}
}
return Bitmap.createBitmap(this, left, bottom, right - left, top - bottom)
}

Following the official doc:
The new bitmap may be the same object as source, or a copy may have been made.
You should take into account when you execute .recycle() with the source bitmap.

Reducing Bar graph width in Android Graphview library

I am using GraphView Library for creating Bar graph as shown in picture, I need to reduce width of bars and increase space between bars.
Note- Red bars are currently what I'm getting and what I actually need is shown in black.
Below is the code snippet for the above graph:
GraphViewSeriesStyle barStyle = new GraphViewSeriesStyle();
barStyle.thickness = 5;
barStyle.setValueDependentColor(new ValueDependentColor() {
#Override
public int get(GraphViewDataInterface data) {
return Color.rgb(205, 0, 0);
}
});
// init example series data
GraphViewSeries scoreSeries = new GraphViewSeries(
"HealthCare Bar Graph", barStyle, new GraphViewData[] {
new GraphViewData(1, rsCVD),
new GraphViewData(2, rsHypertension4),
new GraphViewData(3, rsHypertension2),
new GraphViewData(4, rsHypertension1) });
GraphView graphView = new BarGraphView(this // context
, "GRAPH_VIEW_HEADING" // heading
);
graphView.setHorizontalLabels(new String[] { "1", "2",
"3", "4" });
graphView.addSeries(scoreSeries);
graphView.setViewPort(0, 25);
graphView.setScalable(true);
graphView.getGraphViewStyle().setHorizontalLabelsColor(Color.BLACK);
graphView.getGraphViewStyle().setVerticalLabelsColor(Color.BLACK);
graphView.getGraphViewStyle().setTextSize(16);
graphView.getGraphViewStyle().setGridColor(Color.WHITE);
// graphView.getGraphViewStyle().setLegendWidth(legendWidth)
int maxValue = myScore+1;
// search the interval between 2 vertical labels
double interval;
if (maxValue >= 0 && maxValue < 3) {
interval = 0.5; // increment of 1 between each label
} else if (maxValue >= 3 && maxValue < 55) {
interval = 5; // increment of 5 between each label
} else if (maxValue >= 55 && maxValue <= 110) {
interval = 10; // increment of 10 between each label
} else {
interval = 20; // increment of 20 between each label
}
// search the top value of our graph
int maxLabel = maxValue;
while (maxLabel % interval != 0) {
maxLabel++;
}
// set manual bounds
graphView.setManualYAxisBounds(maxLabel, 0);
// indicate number of vertical labels
int numVerticalLabels = (int) ((int) maxLabel / interval + 1);
Log.v(TAG, "numVerticalLabels: " + numVerticalLabels);
graphView.getGraphViewStyle().setNumVerticalLabels(numVerticalLabels);
graphView.getGraphViewStyle().setVerticalLabelsWidth(20);
// graphView.getGraphViewStyle().setLegendWidth(20);
graphView.getGraphViewStyle().setLegendSpacing(30);
// LinearLayout layout = (LinearLayout) findViewById(R.id.layout);
m_llayForRiskGraphContainer.addView(graphView);

there's currently no build in method to do this. but if you want to, you can easily modify the code. The point where you can add a spacing is here:
BarGraphView.java Line 95:
float left = (i * colwidth) + horstart -offset;
float top = (border - y) + graphheight;
float right = ((i * colwidth) + horstart) + (colwidth - 1) -offset;
canvas.drawRect(left, top, right, graphheight + border - 1, paint);
Just add a few pixels to left and remove a few pixels from right and it will look like you want.
https://github.com/jjoe64/GraphView/blob/master/src/main/java/com/jjoe64/graphview/BarGraphView.java#L97