android之豆瓣項(xiàng)目開發(fā)教程源碼圖片處理

Android圖形處理專題Load圖形到內(nèi)存1.數(shù)碼相機(jī)照片特別大3m以上,內(nèi)存吃不消,只顯示原圖的1/8通過BitmapFactory.Options來實(shí)現(xiàn)BitmapFactory.OptionsbmpFactoryOptions=newBitmapFactory.Options();bmpFactoryOptions.inSampleSize=8;Bitmapbmp=BitmapFactory.decodeFile(imageFilePath,bmpFactoryOptions);imv.setImageBitmap(bmp);Load圖形到內(nèi)存2.根據(jù)當(dāng)前屏幕分辨率的大小,加載圖片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圖形到內(nèi)存2//判斷是否要進(jìn)行縮放if(heightRatio>1&&widthRatio>1){if(heightRatio>widthRatio){//高度變化大,按高度縮放bmpFactoryOptions.inSampleSize=heightRatio;}else{//寬度變化大,按寬度縮放bmpFactoryOptions.inSampleSize=widthRatio;}}bmpFactoryOptions.inJustDecodeBounds=false;bmp=BitmapFactory.decodeFile(imageFilePath,bmpFactoryOptions);獲取Exif圖片信息//從文件獲取exif信息ExifInterfaceei=newExifInterface(imageFilePath);StringimageDescription=ei.getAttribute("ImageDescription");if(imageDescription!=null){Log.v("EXIF",imageDescription);}//把exif信息寫到文件:ExifInterfaceei=newExifInterface(imageFilePath);ei.setAttribute("ImageDescription","SomethingNew");從gallery獲取一個(gè)圖片Intentintent=newIntent(Intent.ACTION_PICK);intent.setType(“image/*”);intent.getData()獲取image的uriBitmapbmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri),null,bmpFactoryOptions);創(chuàng)建bitmap拷貝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);圖形縮放Matrixmatrix=newMatrix();matrix.setValues(newfloat[]{ 1,0,0, 0,1,0, 0,0,1});x=1x+0y+0zy=0x+1y+0zz=0x+0y+1z通過canvas.drawBitmap(bmp,matrix,paint);創(chuàng)建bitmap1.水平縮放0.52.垂直拉扯2倍matrix.setScale(1.5f,1);//水平點(diǎn)放大到1.5f,垂直1圖形旋轉(zhuǎn)Matrixmatrix=newMatrix();matrix.setRotate(15);canvas.drawBitmap(bmp,matrix,paint);消除鋸齒paint.setAntiAlias(true);指定圓心的旋轉(zhuǎn)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);圖形平移setTranslate(1.5f,-10);鏡子效果matrix.setScale(-1,1);matrix.postTranslate(bmp.getWidth(),0);倒影效果matrix.setScale(1,-1);matrix.postTranslate(0,bmp.getHeight());圖像顏色處理顏色矩陣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));變換圖像的亮度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));更改圖片飽和度ColorMatrixcm=newColorMatrix();cm.setSaturation(.5f);paint.setColorFilter(newColorMatrixColorFilter(cm));圖片合成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上繪制文字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);圖片編輯畫畫板人臉識(shí)別FaceDetectordetector=newFaceDetector(faceBitmap.getWidth(),faceBitmap.getHeight(),3);//創(chuàng)建識(shí)別器mNumFaces