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I am making an app for exposure fusion but I have a small hiccup on my ZTE test device. On the Pixel emulator, I am able to take an Image from the ImageReader and convert it to a Mat and then back to a Bitmap to be displayed in an ImageView. This is the code:
int width = image.getWidth();
int height = image.getHeight();
Image.Plane yPlane = image.getPlanes()[0];
Image.Plane uPlane = image.getPlanes()[1];
Image.Plane vPlane = image.getPlanes()[2];
ByteBuffer yBuffer = yPlane.getBuffer();
ByteBuffer uBuffer = uPlane.getBuffer();
ByteBuffer vBuffer = vPlane.getBuffer();
int ySize = yBuffer.remaining();
int uSize = uBuffer.remaining();
int vSize = vBuffer.remaining();
int uvPixelStride = uPlane.getPixelStride();
Mat yuvMat = new Mat(height + (height / 2), width, CvType.CV_8UC1);
byte[] data = new byte[ySize + uSize + vSize];
yBuffer.get(data, 0, ySize);
uBuffer.get(data, ySize, uSize);
vBuffer.get(data, ySize + uSize, vSize);
if (uvPixelStride == 1) {
yuvMat.put(0, 0, data);
Mat rgb = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC4);
Imgproc.cvtColor(yuvMat, rgb, Imgproc.COLOR_YUV420p2RGBA);
return rgb;
Now, for the ZTE, the pixel stride for the U and V planes are 2 but I can't seem to get it to display correctly.
This is the code I'm using right now:
Mat yuv = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC1);
yuv.put(0, 0, data);
Mat rgb = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC4);
Imgproc.cvtColor(yuv, rgb, Imgproc.COLOR_YUV2RGBA_NV21);
return rgb;
Any help would be greatly appreciated.
I'm trying to use a filter function from OpenCV in Processing, but before I do, I have to convert my image into a mat that is 8 bits and 3 channels. But whenever I run it, I keep running into a "Buffer Overflow Exception," and I can't figure out why I get that error and how to get the conversion to work.
import gab.opencv.*;
import java.nio.*;
import org.opencv.imgproc.Imgproc;
import org.opencv.core.Mat;
import org.opencv.core.CvType;
import org.opencv.core.Core;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
OpenCV opencv;
Imgproc imgproc;
PImage src, out;
PImage before, snap;
Mat one, two;
double a = 35.0;
double b = 20.0;
void setup() {
src = loadImage("cat.jpg");
size( 429, 360);
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
one = new Mat( width, height, CvType.CV_8UC3);
two = new Mat( width, height, CvType.CV_8UC3);
one = toMat(src);
imgproc.pyrMeanShiftFiltering( one, two, a, b);
out = toPImage(two);
}
void draw() {
image(out, 0, 0, width, height);
}
Mat toMat(PImage image) {
int w = image.width;
int h = image.height;
Mat mat = new Mat(h, w, CvType.CV_8UC3);
byte[] data8 = new byte[w*h*3];
int[] data32 = new int[w*h];
arrayCopy(image.pixels, data32);
ByteBuffer bBuf = ByteBuffer.allocate(w*h*3);
IntBuffer iBuf = bBuf.asIntBuffer();
iBuf.put(data32); // ERROR -- BufferOverflowException
bBuf.get(data8);
mat.put(0, 0, data8);
return mat;
}
PImage toPImage(Mat mat) {
int w = mat.width();
int h = mat.height();
PImage image = createImage(w, h, RGB);
byte[] data8 = new byte[w*h*3];
int[] data32 = new int[w*h];
mat.get(0, 0, data8);
ByteBuffer.wrap(data8).asIntBuffer().get(data32);
arrayCopy(data32, image.pixels);
}
I need to take an int array and turn it into BufferImage. I really don't have any background on this subject and I learn it all from the internet so here's what I'm trying to do:
Create an array from BufferedImage(done), turn this array into IntBuffer(done) - (Later i'll need to do some opertions on the image through the IntBuffer), put the changed values from the IntBuffer in new array(done), and turn this array into WritableRaster.
(If something isn't right in my understading of the process please tell me)
Here's the line where I deal with the WritableRaster:
WritableRaster newRaster= newRaster.setPixels(0, 0, width, height, matrix);
Eclipse marks this as a mistake and says ''Type mismatch:Cannot convert from void to WritableRaster"
Please help! I'm a bit lost.
Also sorry for bad english.
EDIT:
The matrix:
int height=img.getHeight();
int width=img.getWidth();
int[]matrix=new int[width*height];
The part of the code where I try to insert values to the Raster:
BufferedImage finalImg = new BufferedImage(width,height, BufferedImage.TYPE_INT_RGB);
WritableRaster newRaster= (WritableRaster)finalImg.getData();
newRaster.setPixels(0, 0, width, height, matrix);
The error message:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10769
at java.awt.image.SinglePixelPackedSampleModel.setPixels(Unknown Source)
at java.awt.image.WritableRaster.setPixels(Unknown Source)
You can create a WritableRaster and/or BufferedImage from an int array like this:
int w = 300;
int h = 200;
int[] matrix = new int[w * h];
// ...manipulate the matrix...
DataBufferInt buffer = new DataBufferInt(matrix, matrix.length);
int[] bandMasks = {0xFF0000, 0xFF00, 0xFF, 0xFF000000}; // ARGB (yes, ARGB, as the masks are R, G, B, A always) order
WritableRaster raster = Raster.createPackedRaster(buffer, w, h, w, bandMasks, null);
System.out.println("raster: " + raster);
ColorModel cm = ColorModel.getRGBdefault();
BufferedImage image = new BufferedImage(cm, raster, cm.isAlphaPremultiplied(), null);
System.err.println("image: " + image);
ColorModel cm = ColorModel.getRGBdefault();
int w = 300;
int h = 200;
WritableRaster raster = cm.createCompatibleWritableRaster(w, h);
DataBufferInt buffer = (DataBufferInt) raster.getDataBuffer();
int[] bufferData = buffer.getData();
int[] array = new int[2400];
Random random = new Random();
for (int i = 0; i < 2400; i++) {
array[i] = random.nextInt(2);
}
System.arraycopy(array, 0, bufferData, 0, (array.length < bufferData.length ? array.length : bufferData.length));
BufferedImage image = new BufferedImage(cm, raster, false, null);
FileOutputStream fos = new FileOutputStream("D:\\abc\\OCR\\" + "LearningRaster" + ".png");
ImageIO.write(image, "PNG", fos);
fos.close();
setPixels returns void:
public static void setPixels(BufferedImage img,
int x, int y, int w, int h, int[] pixels)
so you need to create Raster and than set pixels to it:
WritableRaster newRaster= WritableRaster.createWritableRaster(…);
newRaster.setPixels(0, 0, width, height, matrix);
You need to put 4 int per pixel (it depends on color model, 4 for ARGB). So, matrix size must be
int[] matrix = new int[width * height * 4]
See more about WritableRaster here —
Oracle: WritableRaster
Code examples
How can I convert a BufferedImage to a Mat in OpenCV?
I'm using the JAVA wrapper for OpenCV(not JavaCV). As I am new to OpenCV I have some problems understanding how Mat works.
I want to do something like this. (Based on Ted W. reply):
BufferedImage image = ImageIO.read(b.getClass().getResource("Lena.png"));
int rows = image.getWidth();
int cols = image.getHeight();
int type = CvType.CV_16UC1;
Mat newMat = new Mat(rows, cols, type);
for (int r = 0; r < rows; r++) {
for (int c = 0; c < cols; c++) {
newMat.put(r, c, image.getRGB(r, c));
}
}
Highgui.imwrite("Lena_copy.png", newMat);
This doesn't work. Lena_copy.png is just a black picture with the correct dimensions.
I also was trying to do the same thing, because of need to combining image processed with two libraries. And what I’ve tried to do is to put byte[] in to Mat instead of RGB value. And it worked! So what I did was:
1.Converted BufferedImage to byte array with:
byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
2. Then you can simply put it to Mat if you set type to CV_8UC3
image_final.put(0, 0, pixels);
Edit:
Also you can try to do the inverse as on this answer
Don't want to deal with big pixel array? Simply use this
BufferedImage to Mat
public static Mat BufferedImage2Mat(BufferedImage image) throws IOException {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", byteArrayOutputStream);
byteArrayOutputStream.flush();
return Imgcodecs.imdecode(new MatOfByte(byteArrayOutputStream.toByteArray()), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
}
Mat to BufferedImage
public static BufferedImage Mat2BufferedImage(Mat matrix)throws IOException {
MatOfByte mob=new MatOfByte();
Imgcodecs.imencode(".jpg", matrix, mob);
return ImageIO.read(new ByteArrayInputStream(mob.toArray()));
}
Note, Though it's very negligible. However, in this way, you can get a reliable solution but it uses encoding + decoding. So you lose some performance. It's generally 10 to 20 milliseconds. JPG encoding loses some image quality also it's slow (may take 10 to 20ms). BMP is lossless and fast (1 or 2 ms) but requires little more memory (negligible). PNG is lossless but a little more time to encode than BMP. Using BMP should fit the most cases I think.
This one worked fine for me, and it takes from 0 to 1 ms to be performed.
public static Mat bufferedImageToMat(BufferedImage bi) {
Mat mat = new Mat(bi.getHeight(), bi.getWidth(), CvType.CV_8UC3);
byte[] data = ((DataBufferByte) bi.getRaster().getDataBuffer()).getData();
mat.put(0, 0, data);
return mat;
}
I use following code in my program.
protected Mat img2Mat(BufferedImage in) {
Mat out;
byte[] data;
int r, g, b;
if (in.getType() == BufferedImage.TYPE_INT_RGB) {
out = new Mat(in.getHeight(), in.getWidth(), CvType.CV_8UC3);
data = new byte[in.getWidth() * in.getHeight() * (int) out.elemSize()];
int[] dataBuff = in.getRGB(0, 0, in.getWidth(), in.getHeight(), null, 0, in.getWidth());
for (int i = 0; i < dataBuff.length; i++) {
data[i * 3] = (byte) ((dataBuff[i] >> 0) & 0xFF);
data[i * 3 + 1] = (byte) ((dataBuff[i] >> 8) & 0xFF);
data[i * 3 + 2] = (byte) ((dataBuff[i] >> 16) & 0xFF);
}
} else {
out = new Mat(in.getHeight(), in.getWidth(), CvType.CV_8UC1);
data = new byte[in.getWidth() * in.getHeight() * (int) out.elemSize()];
int[] dataBuff = in.getRGB(0, 0, in.getWidth(), in.getHeight(), null, 0, in.getWidth());
for (int i = 0; i < dataBuff.length; i++) {
r = (byte) ((dataBuff[i] >> 0) & 0xFF);
g = (byte) ((dataBuff[i] >> 8) & 0xFF);
b = (byte) ((dataBuff[i] >> 16) & 0xFF);
data[i] = (byte) ((0.21 * r) + (0.71 * g) + (0.07 * b));
}
}
out.put(0, 0, data);
return out;
}
Reference: here
I found a solution here.
The solution is similar to Andriys.
Camera c;
c.Connect();
c.StartCapture();
Image f2Img, cf2Img;
c.RetrieveBuffer(&f2Img);
f2Img.Convert( FlyCapture2::PIXEL_FORMAT_BGR, &cf2Img );
unsigned int rowBytes = (double)cf2Img.GetReceivedDataSize()/(double)cf2Img.GetRows();
cv::Mat opencvImg = cv::Mat( cf2Img.GetRows(), cf2Img.GetCols(), CV_8UC3, cf2Img.GetData(),rowBytes );
To convert from BufferedImage to Mat I use the method below:
public static Mat img2Mat(BufferedImage image) {
image = convertTo3ByteBGRType(image);
byte[] data = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
Mat mat = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, data);
return mat;
}
Before converting into Mat, I change the type of bufferedImage to TYPE_3BYTE_BGR, because to some types BufferedImages the method ((DataBufferByte) image.getRaster().getDataBuffer()).getData(); may return int[] and that would break the code.
Below is the method for converting to TYPE_3BYTE_BGR.
private static BufferedImage convertTo3ByteBGRType(BufferedImage image) {
BufferedImage convertedImage = new BufferedImage(image.getWidth(), image.getHeight(),
BufferedImage.TYPE_3BYTE_BGR);
convertedImage.getGraphics().drawImage(image, 0, 0, null);
return convertedImage;
}
When you use as JavaCP wrapper bytedeco library (version 1.5.3) then you can use Java2DFrameUtils.
Simple usage is:
import org.bytedeco.javacv.Java2DFrameUtils;
...
BufferedImage img = ImageIO.read(new File("some/image.jpg");
Mat mat = Java2DFrameUtils.toMat(img);
Note: don't mix different wrappers, bytedeco Mat is different than opencv Mat.
One simple way would be to create a new using
Mat newMat = Mat(rows, cols, type);
then get the pixel values from your BufferedImage and put into newMat using
newMat.put(row, col, pixel);
You can do it in OpenCV as follows:
File f4 = new File("aa.png");
Mat mat = Highgui.imread(f4.getAbsolutePath());
Is there a way in Java or OpenCv ; preferably Java, that i can have an HSV histogram give RGB image.
I tried exploring JAI but it creates histogram for RGB image.
Thanks
Harshit
firs use cv::cvtColor to convert RGB to HSV
then use cv::calcHist to compute the histogram
Here is the pseudocode for a simple RGB to HSV converter. It will give a H of UNDEFINED if the color is a shade of gray, otherwise H is between 0 and 6.
x = min(R, G, B);
V = max(R, G, B);
if (V == x) {
H = UNDEFINED
S = 0
}
else {
if( R == x ) {
f = G - B;
i = 3;
} else if( G == x ) {
f = B - R;
i = 5;
} else {
f = R - G;
i = 1;
}
H = i - f /(V - x);
S = (V - x)/V;
}
Now you can either convert all your pixels and bin them to construct your HSV histogram, or you can convert each bin of your RGB histogram to an HSV bin.
You can use the "JavaCV" library to access OpenCV functions directly from Java:
http://code.google.com/p/javacv/
Then you can use my code for RGB to HSV that is better than OpenCV's cvConvert function:
http://www.shervinemami.co.cc/colorConversion.html
Cheers,
Shervin Emami.
Here is a code to do this:
// Assume SourceImage is a Bitmap ARGB_8888
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap refImage = BitmapFactory.decodeFile(mBaseDir + "some_reference.jpg", options);
Mat hsvRef = new Mat();
Mat hsvSource = new Mat();
Mat srcRef = new Mat(refImage.getHeight(), refImage.getWidth(), CvType.CV_8U, new Scalar(4));
Utils.bitmapToMat(refImage, srcRef);
Mat srcSource = new Mat(SourceImage.getHeight(), SourceImage.getWidth(), CvType.CV_8U, new Scalar(4));
Utils.bitmapToMat(SourceImage, srcSource);
/// Convert to HSV
Imgproc.cvtColor(srcRef, hsvRef, Imgproc.COLOR_BGR2HSV);
Imgproc.cvtColor(srcSource, hsvSource, Imgproc.COLOR_BGR2HSV);
/// Using 50 bins for hue and 60 for saturation
int hBins = 50;
int sBins = 60;
MatOfInt histSize = new MatOfInt( hBins, sBins);
// hue varies from 0 to 179, saturation from 0 to 255
MatOfFloat ranges = new MatOfFloat( 0f,180f,0f,256f );
// we compute the histogram from the 0-th and 1-st channels
MatOfInt channels = new MatOfInt(0, 1);
Mat histRef = new Mat();
Mat histSource = new Mat();
ArrayList<Mat> histImages=new ArrayList<Mat>();
histImages.add(hsvRef);
Imgproc.calcHist(histImages,
channels,
new Mat(),
histRef,
histSize,
ranges,
false);
Core.normalize(histRef,
histRef,
0,
1,
Core.NORM_MINMAX,
-1,
new Mat());
histImages=new ArrayList<Mat>();
histImages.add(hsvSource);
Imgproc.calcHist(histImages,
channels,
new Mat(),
histSource,
histSize,
ranges,
false);
Core.normalize(histSource,
histSource,
0,
1,
Core.NORM_MINMAX,
-1,
new Mat());
double resp1 = Imgproc.compareHist(histRef, histSource, 0);
double resp2 = Imgproc.compareHist(histRef, histSource, 1);
double resp3 = Imgproc.compareHist(histRef, histSource, 2);
double resp4 = Imgproc.compareHist(histRef, histSource, 3);
First, you have to convert image to HSV using cv::cvtColor to convert RGB image into HSV image and then, you can use cv::calcHist to compute the HSV histogram.