android之豆瓣项目开发教程源码图片处理

Android图形处理专题Load图形到内存1.数码相机照片特别大3m以上,内存吃不消,只显示原图的1/8通过BitmapFactory.Options来实现BitmapFactory.OptionsbmpFactoryOptions=newBitmapFactory.Options();bmpFactoryOptions.inSampleSize=8;Bitmapbmp=BitmapFactory.decodeFile(imageFilePath,bmpFactoryOptions);imv.setImageBitmap(bmp);Load图形到内存2.根据当前屏幕分辨率的大小,加载图片DisplaycurrentDisplay=getWindowManager().getDefaultDisplay();intdw=currentDisplay.getWidth();intdh=currentDisplay.getHeight();BitmapFactory.OptionsbmpFactoryOptions=newBitmapFactory.Options();bmpFactoryOptions.inJustDecodeBounds=true;Bitmapbmp=BitmapFactory.decodeFile(imageFilePath,bmpFactoryOptions);intheightRatio=(int)Math.ceil(bmpFactoryOptions.outHeight/(float)dh);intwidthRatio=(int)Math.ceil(bmpFactoryOptions.outWidth/(float)dw);Log.v("HEIGHTRATIO",""+heightRatio);Log.v("WIDTHRATIO",""+widthRatio);Load图形到内存2//判断是否要进行缩放if(heightRatio>1&&widthRatio>1){if(heightRatio>widthRatio){//高度变化大,按高度缩放bmpFactoryOptions.inSampleSize=heightRatio;}else{//宽度变化大,按宽度缩放bmpFactoryOptions.inSampleSize=widthRatio;}}bmpFactoryOptions.inJustDecodeBounds=false;bmp=BitmapFactory.decodeFile(imageFilePath,bmpFactoryOptions);获取Exif图片信息//从文件获取exif信息ExifInterfaceei=newExifInterface(imageFilePath);StringimageDescription=ei.getAttribute("ImageDescription");if(imageDescription!=null){Log.v("EXIF",imageDescription);}//把exif信息写到文件:ExifInterfaceei=newExifInterface(imageFilePath);ei.setAttribute("ImageDescription","SomethingNew");从gallery获取一个图片Intentintent=newIntent(Intent.ACTION_PICK);intent.setType(“image/*”);intent.getData()获取image的uriBitmapbmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri),null,bmpFactoryOptions);创建bitmap拷贝Bitmapbmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri),null,bmpFactoryOptions);BitmapalteredBitmap=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());Canvascanvas=newCanvas(alteredBitmap);Paintpaint=newPaint();canvas.drawBitmap(bmp,0,0,paint);图形缩放Matrixmatrix=newMatrix();matrix.setValues(newfloat[]{ 1,0,0, 0,1,0, 0,0,1});x=1x+0y+0zy=0x+1y+0zz=0x+0y+1z通过canvas.drawBitmap(bmp,matrix,paint);创建bitmap1.水平缩放0.52.垂直拉扯2倍matrix.setScale(1.5f,1);//水平点放大到1.5f,垂直1图形旋转Matrixmatrix=newMatrix();matrix.setRotate(15);canvas.drawBitmap(bmp,matrix,paint);消除锯齿paint.setAntiAlias(true);指定圆心的旋转matrix.setRotate(15,bmp.getWidth()/2,bmp.getHeight()/2);Matrixmatrix=newMatrix();matrix.setRotate(15,bmp.getWidth()/2,bmp.getHeight()/2);alteredBitmap=Bitmap.createBitmap(bmp,0,0,bmp.getWidth(),bmp.getHeight(),matrix,false);alteredImageView.setImageBitmap(alteredBitmap);图形平移setTranslate(1.5f,-10);镜子效果matrix.setScale(-1,1);matrix.postTranslate(bmp.getWidth(),0);倒影效果matrix.setScale(1,-1);matrix.postTranslate(0,bmp.getHeight());图像颜色处理颜色矩阵ColorMatrixcm=newColorMatrix();paint.setColorFilter(newColorMatrixColorFilter(cm));10000010000010000010NewRedValue=1*128+0*128+0*128+0*0+0NewBlueValue=0*128+1*128+0*128+0*0+0NewGreenValue=0*128+0*128+1*128+0*0+0NewAlphaValue=0*128+0*128+0*128+1*0+0ColorMatrixcm=newColorMatrix();cm.set(newfloat[]{2,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0});paint.setColorFilter(newColorMatrixColorFilter(cm));变换图像的亮度ColorMatrixcm=newColorMatrix();floatcontrast=2;cm.set(newfloat[]{contrast,0,0,0,0,0,contrast,0,0,0,0,0,contrast,0,0,0,0,0,1,0});paint.setColorFilter(newColorMatrixColorFilter(cm));更改图片饱和度ColorMatrixcm=newColorMatrix();cm.setSaturation(.5f);paint.setColorFilter(newColorMatrixColorFilter(cm));图片合成BitmapdrawingBitmap=Bitmap.createBitmap(bmp1.getWidth(),bmp1.getHeight(),bmp1.getConfig());canvas=newCanvas(drawingBitmap);paint=newPaint();canvas.drawBitmap(bmp1,0,0,paint);paint.setXfermode(newPorterDuffXfermode(android.graphics.PorterDuff.Mode.MULTIPLY));canvas.drawBitmap(bmp2,0,0,paint);按指定path上绘制文字Paintpaint=newPaint();paint.setColor(Color.GREEN);paint.setTextSize(20);paint.setTypeface(Typeface.DEFAULT);Pathp=newPath();p.moveTo(20,20);p.lineTo(100,150);p.lineTo(200,220);canvas.drawTextOnPath("Hellothisistextonapath",p,0,0,paint);图片编辑画画板人脸识别FaceDetectordetector=newFaceDetector(faceBitmap.getWidth(),faceBitmap.getHeight(),3);//创建识别器mNumFaces