एंड्रॉइड

Question

पर कुछ मामलों में एक क्वाड्रैंगल में छवि को विकृत करना विफल रहता है, मैं एक बिटमैप के एक चयनित क्षेत्र (4 कोनों) को एक आयत में बदलने के लिए matrix.setPolyToPoly फ़ंक्शन का उपयोग कर रहा हूं और आमतौर पर यह अद्भुत काम करता है। लेकिन अगले उदाहरण में:

polyToPoly समारोह परिप्रेक्ष्य बदलने विफल रहता है:

मैं परीक्षण के लिए दो पंक्तियों तैयार की है, लाइनों चिह्नित जहां मैं चार चयनित अंक चाहते हैं ।

मैं क्या गलत कर रहा हूं? धन्यवाद!

संपादित करें: मैंने आपकी सलाह के लिए canvas.drawBitmapMesh का उपयोग कर समस्या हल की है, धन्यवाद pskink !!

इस अंतिम कोड

private float[] generateVertices(int widthBitmap, int heightBitmap) { 
    float[] vertices=new float[(WIDTH_BLOCK+1)*(HEIGHT_BLOCK+1)*2]; 

    float widthBlock = (float)widthBitmap/WIDTH_BLOCK; 
    float heightBlock = (float)heightBitmap/HEIGHT_BLOCK; 

    for(int i=0;i<=HEIGHT_BLOCK;i++) 
     for(int j=0;j<=WIDTH_BLOCK;j++) { 
      vertices[i * ((HEIGHT_BLOCK+1)*2) + (j*2)] = j * widthBlock; 
      vertices[i * ((HEIGHT_BLOCK+1)*2) + (j*2)+1] = i * heightBlock; 
     } 
    return vertices; 
} 

private Bitmap perspectiveTransformation(Bitmap bitmap, ArrayList<Point> bitmapPoints) { 

    Bitmap correctedBitmap; 
    int maxX = (int) Math.max(Math.abs(bitmapPoints.get(0).x - bitmapPoints.get(1).x), Math.abs(bitmapPoints.get(2).x - bitmapPoints.get(3).x)); 
    int maxY = (int) Math.max(Math.abs(bitmapPoints.get(0).y - bitmapPoints.get(3).y), Math.abs(bitmapPoints.get(1).y - bitmapPoints.get(2).y)); 
    Log.d("max", "x=" + maxX + " y=" + maxY); //This is the desired final size 

    Bitmap.Config conf = Bitmap.Config.ARGB_8888; 
    correctedBitmap = Bitmap.createBitmap(maxX,maxY,conf); //the final bitmap 
    float mVertices[] =generateVertices(bitmap.getWidth(),bitmap.getHeight()); 

    Point mLeftTop = bitmapPoints.get(0); 
    Point mRightTop = bitmapPoints.get(1); 
    Point mLeftBot = bitmapPoints.get(3); 
    Point mRightBot = bitmapPoints.get(2); //the points on the image where the user has clicked 

    Canvas canvas = new Canvas(correctedBitmap); 

    Matrix matrix = new Matrix(); 
    matrix.setPolyToPoly(
      new float[]{mLeftTop.x, mLeftTop.y, 
        mRightTop.x, mRightTop.y, 
        mRightBot.x, mRightBot.y, 
        mLeftBot.x, mLeftBot.y //the user's points 
      }, 
      0, 
      new float[]{0, 0, 
        maxX - 1, 0, 
        maxX - 1, maxY - 1, 
        0, maxY - 1    //where I want the user points in the corrected image 
      } 
      , 0, 4); 

    canvas.concat(matrix); 

    Paint paint = new Paint(); 
    paint.setAntiAlias(true);  //testing parameters 
    paint.setFilterBitmap(true); //testing parameters 

    paint.setColor(Color.BLUE); 
    paint.setStyle(Paint.Style.STROKE); 

    canvas.drawBitmapMesh(bitmap, WIDTH_BLOCK , HEIGHT_BLOCK, mVertices,0,null,0, paint); //draw the original bitmap into the corrected bitmap with PolyToPoly transformation matrix 

    canvas.drawLine(mLeftTop.x, mLeftTop.y, mRightBot.x, mRightBot.y, paint); //draw two lines for testing the transformation matrix 
    canvas.drawLine(mLeftBot.x, mLeftBot.y, mRightTop.x, mRightTop.y, paint); 

    //bitmap.recycle(); //just testing 

    return correctedBitmap; 
} 

Answer 1

private float[] generateVertices(int widthBitmap, int heightBitmap) { 
    float[] vertices=new float[(WIDTH_BLOCK+1)*(HEIGHT_BLOCK+1)*2]; 

    float widthBlock = (float)widthBitmap/WIDTH_BLOCK; 
    float heightBlock = (float)heightBitmap/HEIGHT_BLOCK; 

    for(int i=0;i<=HEIGHT_BLOCK;i++) 
     for(int j=0;j<=WIDTH_BLOCK;j++) { 
      vertices[i * ((HEIGHT_BLOCK+1)*2) + (j*2)] = j * widthBlock; 
      vertices[i * ((HEIGHT_BLOCK+1)*2) + (j*2)+1] = i * heightBlock; 
     } 
    return vertices; 
} 

private Bitmap perspectiveTransformation(Bitmap bitmap, ArrayList<Point> bitmapPoints) { 

    Bitmap correctedBitmap; 
    int maxX = (int) Math.max(Math.abs(bitmapPoints.get(0).x - bitmapPoints.get(1).x), Math.abs(bitmapPoints.get(2).x - bitmapPoints.get(3).x)); 
    int maxY = (int) Math.max(Math.abs(bitmapPoints.get(0).y - bitmapPoints.get(3).y), Math.abs(bitmapPoints.get(1).y - bitmapPoints.get(2).y)); 
    Log.d("max", "x=" + maxX + " y=" + maxY); //This is the desired final size 

    Bitmap.Config conf = Bitmap.Config.ARGB_8888; 
    correctedBitmap = Bitmap.createBitmap(maxX,maxY,conf); //the final bitmap 
    float mVertices[] =generateVertices(bitmap.getWidth(),bitmap.getHeight()); 

    Point mLeftTop = bitmapPoints.get(0); 
    Point mRightTop = bitmapPoints.get(1); 
    Point mLeftBot = bitmapPoints.get(3); 
    Point mRightBot = bitmapPoints.get(2); //the points on the image where the user has clicked 

    Canvas canvas = new Canvas(correctedBitmap); 

    Matrix matrix = new Matrix(); 
    matrix.setPolyToPoly(
      new float[]{mLeftTop.x, mLeftTop.y, 
        mRightTop.x, mRightTop.y, 
        mRightBot.x, mRightBot.y, 
        mLeftBot.x, mLeftBot.y //the user's points 
      }, 
      0, 
      new float[]{0, 0, 
        maxX - 1, 0, 
        maxX - 1, maxY - 1, 
        0, maxY - 1    //where I want the user points in the corrected image 
      } 
      , 0, 4); 

    canvas.concat(matrix); 

    Paint paint = new Paint(); 
    paint.setAntiAlias(true);  //testing parameters 
    paint.setFilterBitmap(true); //testing parameters 

    paint.setColor(Color.BLUE); 
    paint.setStyle(Paint.Style.STROKE); 

    canvas.drawBitmapMesh(bitmap, WIDTH_BLOCK , HEIGHT_BLOCK, mVertices,0,null,0, paint); //draw the original bitmap into the corrected bitmap with PolyToPoly transformation matrix 

    canvas.drawLine(mLeftTop.x, mLeftTop.y, mRightBot.x, mRightBot.y, paint); //draw two lines for testing the transformation matrix 
    canvas.drawLine(mLeftBot.x, mLeftBot.y, mRightTop.x, mRightTop.y, paint); 

    //bitmap.recycle(); //just testing 

    return correctedBitmap; 
}