调整大小的图片，同时还美元的Android p $ pserving质量 [英] Resizing pictures while still preserving quality in android
本文介绍了调整大小的图片，同时还美元的Android p $ pserving质量的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想减少低于100 KB的图像文件的大小，而preserving图像质量例如WhatsApp和Facebook一样。
我试过几乎所有的$ C $ Android的形象融为一体pression的C语言中的计算器，但这并不为我工作。
现在我下面的这个博客缩小图像大小，我得到低于100 KB的图像，但图像质量较差。
有什么办法，我可以减少低于100 KB，而图片大小
preserving质量？ （原始图像大小可以变化从20 KB至8 MB）我试过JAI库的Java项目，而且它的工作好。
我可以用JAI库在android系统，以减少图像的大小???
先谢谢了。
来源$ C $ C到COM preSS图像：
进口java.io.ByteArrayOutputStream中;
进口的java.io.File;
进口java.io.FileNotFoundException;
进口java.io.FileOutputStream中;
进口java.io.IOException异常;
进口java.math.BigInteger的;
进口java.text.SimpleDateFormat的;
进口java.util.Date;
进口java.util.Locale中;进口android.graphics.Bitmap;
进口android.graphics.BitmapFactory;
进口android.graphics.Canvas;
进口android.graphics.Matrix;
进口android.graphics.Paint;
进口android.media.ExifInterface;
进口android.os.Environment;
进口android.util.Log;公共类的COM $ P $ {pssBitmap 私人字符串路径;
公众的COM pressBitmap（字符串路径）{
this.path =路径;
} 公共ByteArrayOutputStream getBitmap（）{
ByteArrayOutputStream outStream =新ByteArrayOutputStream（）;
getscaledImage（路径）.COM preSS（Bitmap.Com pressFormat.JPEG，100，outStream）;
返回outStream;
} 公共ByteArrayOutputStream getBitmap（INT质量）{
ByteArrayOutputStream outStream =新ByteArrayOutputStream（）;
getscaledImage（路径）.COM preSS（Bitmap.Com pressFormat.JPEG，质量，outStream）;
返回outStream;
} 公共字符串getComressFile（）{
FileOutputStream中走出= NULL;
字符串文件名= createImageFile（）;
尝试{
OUT =新的FileOutputStream（文件名）;
getscaledImage（路径）.COM preSS（Bitmap.Com pressFormat.JPEG，80出）;
}赶上（FileNotFoundException异常五）{
e.printStackTrace（）;
}
档案文件=新的文件（文件名）;
Log.e（长度，图像大小+ file.length（））;
返回的文件名;
} 私人位图getscaledImage（字符串文件路径）{
位图scaledBitmap = NULL; BitmapFactory.Options选项=新BitmapFactory.Options（）;
options.inJustDe codeBounds = TRUE;
BMP位图= BitmapFactory.de codeFILE（文件路径，期权）; INT的ActualHeight = options.outHeight;
INT ActualWidth的= options.outWidth;
浮了maxHeight = 800.0f;
浮了maxWidth = 600.0f;
浮imgRatio = ActualWidth的/的ActualHeight;
浮maxRatio =了maxWidth /了maxHeight; Log.v（图片，缩放宽度和高度都是之前+ ActualWidth的+ - +的ActualHeight）; 如果（的ActualHeight＆GT;了maxHeight || ActualWidth的＆GT;了maxWidth）{
如果（imgRatio＆LT; maxRatio）{
imgRatio =了maxHeight /的ActualHeight;
ActualWidth的=（INT）（imgRatio * ActualWidth的）;
的ActualHeight =（INT）了maxHeight;
}否则如果（imgRatio＆GT; maxRatio）{
imgRatio =了maxWidth / ActualWidth的;
的ActualHeight =（INT）（imgRatio *的ActualHeight）;
ActualWidth的=（INT）了maxWidth;
}其他{
的ActualHeight =（INT）了maxHeight;
ActualWidth的=（INT）了maxWidth;
}
} options.inSampleSize = calculateInSampleSize（选项，ActualWidth的，的ActualHeight）;
options.inJustDe codeBounds = FALSE;
options.inDither = FALSE;
options.inPurgeable = TRUE;
options.inInputShareable = TRUE;
options.inTempStorage =新的字节[16 * 1024]; 尝试{
BMP = BitmapFactory.de codeFILE（文件路径，期权）;
}
赶上（例外的OutOfMemoryError）{
exception.printStackTrace（）; }
尝试{
scaledBitmap = Bitmap.createBitmap（ActualWidth的，的ActualHeight，Bitmap.Config.ARGB_8888）;
}
赶上（例外的OutOfMemoryError）{
exception.printStackTrace（）;
} 浮ratioX = ActualWidth的/（浮点）options.outWidth;
浮ratioY =的ActualHeight /（浮点）options.outHeight;
浮middleX = ActualWidth的/ 2.0F;
浮middleY =的ActualHeight / 2.0F; 矩阵scaleMatrix =新的Matrix（）;
scaleMatrix.setScale（ratioX，ratioY，middleX，middleY）; 帆布帆布=新的Canvas（scaledBitmap）;
canvas.setMatrix（scaleMatrix）;
canvas.drawBitmap（BMP，middleX - bmp.getWidth（）/ 2，middleY - bmp.getHeight（）/ 2，新油漆（Paint.FILTER_BITMAP_FLAG））; Log.v（图片，缩放后的宽度和高度都是+ scaledBitmap.getWidth（）+ - + scaledBitmap.getHeight（））; ExifInterface EXIF;
尝试{
EXIF =新ExifInterface（文件路径）; INT方向= exif.getAttributeInt（ExifInterface.TAG_ORIENTATION，0）;
Log.d（EXIF，的Exif：+方向）;
字模=新的Matrix（）;
如果（方向== 6）{
matrix.postRotate（90）;
Log.d（EXIF，的Exif：+方向）;
}否则如果（取向== 3）{
matrix.postRotate（180）;
Log.d（EXIF，的Exif：+方向）;
}否则如果（方向== 8）{
matrix.postRotate（270）;
Log.d（EXIF，的Exif：+方向）;
}
scaledBitmap = Bitmap.createBitmap（scaledBitmap，0，0，scaledBitmap.getWidth（），scaledBitmap.getHeight（），矩阵，真）;
}赶上（IOException异常五）{
e.printStackTrace（）;
} 返回scaledBitmap;
} 私人字符串createImageFile（）{
。字符串的timeStamp =新的SimpleDateFormat（YYYYMMDD_HHMMSS，Locale.getDefault（））格式（新的Date（））;
字符串映像文件名称=JPEG_+ +的timeStamp_;
文件storageDir = Environment.getExternalStoragePublicDirectory（
Environment.DIRECTORY_PICTURES）;
文件映像;
尝试{
图像= File.createTempFile（
映像文件名称，/ * preFIX * /
.JPG/ *后缀为* /
storageDir / *目录下的* /
）;
返回image.getAbsolutePath（）;
}赶上（IOException异常五）{
e.printStackTrace（）;
}
返回null;
} 私人诠释calculateInSampleSize（BitmapFactory.Options选项，诠释reqWidth，诠释reqHeight）{
最终诠释身高= options.outHeight;
最终诠释宽度= options.outWidth;
INT inSampleSize = 1; 如果（高度＆GT; reqHeight ||宽度GT; reqWidth）{
最终诠释heightRatio = Math.round（（浮点）高度/（浮点）reqHeight）;
最终诠释widthRatio = Math.round（（浮点）宽/（浮点）reqWidth）;
inSampleSize = heightRatio＆LT; widthRatio？ heightRatio：widthRatio;
}
最终浮动totalPixels =宽*高;
最终浮动totalReqPixelsCap = reqWidth * reqHeight * 2; 而（totalPixels /（inSampleSize * inSampleSize）GT; totalReqPixelsCap）{
inSampleSize ++;
}
返回inSampleSize;
}
}公共无效getBase64（）{
COM pressBitmap COM pressBitmap =新的COM pressBitmap（picturePath）;
//在ImageView的显示COM pressBitmap。 字节[]字节= NULL; 档案文件=新的文件（picturePath）; ByteArrayOutputStream BOS = com的pressBitmap.getBitmap（）;
字节= bos.toByteArray（）;
的base64 = Base64.en codeToString（字节，Base64.DEFAULT）; 返回的base64; //服务器发送的base64字符串
}
解决方案似乎缺少：
options.in preferQualityOverSpeed = TRUE;I want to reduce the image file size below 100 KB while preserving the image quality like whatsapp and facebook did.
I tried almost all the code of android image compression available on stackoverflow but that doesn't work for me.
Right now i am following this blog to reduce the image size, and i am getting the image below 100 KB but image quality is poor.
Is there any way that i can reduce image size below 100 KB while preserving the quality??? (Original Image size can vary from 20 KB to 8 MB)
I tried JAI library in Java Project, and it work good.
Can i Use JAI library in android to reduce image size???
Thanks in Advance.
Source Code to compress an Image:
import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.math.BigInteger; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Locale; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Matrix; import android.graphics.Paint; import android.media.ExifInterface; import android.os.Environment; import android.util.Log; public class CompressBitmap { private String path; public CompressBitmap(String path){ this.path= path; } public ByteArrayOutputStream getBitmap(){ ByteArrayOutputStream outStream = new ByteArrayOutputStream(); getscaledImage(path).compress(Bitmap.CompressFormat.JPEG, 100, outStream); return outStream; } public ByteArrayOutputStream getBitmap(int quality){ ByteArrayOutputStream outStream = new ByteArrayOutputStream(); getscaledImage(path).compress(Bitmap.CompressFormat.JPEG, quality, outStream); return outStream; } public String getComressFile(){ FileOutputStream out = null; String filename = createImageFile(); try { out = new FileOutputStream(filename); getscaledImage(path).compress(Bitmap.CompressFormat.JPEG, 80, out); } catch (FileNotFoundException e) { e.printStackTrace(); } File file = new File(filename); Log.e("SIze of Image","Length"+file.length()); return filename; } private Bitmap getscaledImage(String filePath){ Bitmap scaledBitmap = null; BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; Bitmap bmp = BitmapFactory.decodeFile(filePath,options); int actualHeight = options.outHeight; int actualWidth = options.outWidth; float maxHeight = 800.0f; float maxWidth = 600.0f; float imgRatio = actualWidth / actualHeight; float maxRatio = maxWidth / maxHeight; Log.v("Pictures", "Before scaling Width and height are " + actualWidth + "--" + actualHeight); if (actualHeight > maxHeight || actualWidth > maxWidth) { if (imgRatio < maxRatio) { imgRatio = maxHeight / actualHeight; actualWidth = (int) (imgRatio * actualWidth); actualHeight = (int) maxHeight; } else if (imgRatio > maxRatio) { imgRatio = maxWidth / actualWidth; actualHeight = (int) (imgRatio * actualHeight); actualWidth = (int) maxWidth; } else { actualHeight = (int) maxHeight; actualWidth = (int) maxWidth; } } options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight); options.inJustDecodeBounds = false; options.inDither = false; options.inPurgeable = true; options.inInputShareable = true; options.inTempStorage = new byte[16*1024]; try{ bmp = BitmapFactory.decodeFile(filePath,options); } catch(OutOfMemoryError exception){ exception.printStackTrace(); } try{ scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight, Bitmap.Config.ARGB_8888); } catch(OutOfMemoryError exception){ exception.printStackTrace(); } float ratioX = actualWidth / (float) options.outWidth; float ratioY = actualHeight / (float)options.outHeight; float middleX = actualWidth / 2.0f; float middleY = actualHeight / 2.0f; Matrix scaleMatrix = new Matrix(); scaleMatrix.setScale(ratioX, ratioY, middleX, middleY); Canvas canvas = new Canvas(scaledBitmap); canvas.setMatrix(scaleMatrix); canvas.drawBitmap(bmp, middleX - bmp.getWidth()/2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG)); Log.v("Pictures", "After scaling Width and height are " + scaledBitmap.getWidth() + "--" + scaledBitmap.getHeight()); ExifInterface exif; try { exif = new ExifInterface(filePath); int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 0); Log.d("EXIF", "Exif: " + orientation); Matrix matrix = new Matrix(); if (orientation == 6) { matrix.postRotate(90); Log.d("EXIF", "Exif: " + orientation); } else if (orientation == 3) { matrix.postRotate(180); Log.d("EXIF", "Exif: " + orientation); } else if (orientation == 8) { matrix.postRotate(270); Log.d("EXIF", "Exif: " + orientation); } scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true); } catch (IOException e) { e.printStackTrace(); } return scaledBitmap; } private String createImageFile(){ String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",Locale.getDefault()).format(new Date()); String imageFileName = "JPEG_" + timeStamp + "_"; File storageDir = Environment.getExternalStoragePublicDirectory( Environment.DIRECTORY_PICTURES); File image; try { image = File.createTempFile( imageFileName, /* prefix */ ".jpg", /* suffix */ storageDir /* directory */ ); return image.getAbsolutePath(); } catch (IOException e) { e.printStackTrace(); } return null; } private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) { final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int heightRatio = Math.round((float) height / (float) reqHeight); final int widthRatio = Math.round((float) width / (float) reqWidth); inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio; } final float totalPixels = width * height; final float totalReqPixelsCap = reqWidth * reqHeight * 2; while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) { inSampleSize++; } return inSampleSize; } } public void getBase64() { CompressBitmap compressBitmap = new CompressBitmap(picturePath); //display compressBitmap in ImageView. byte[] bytes=null; File file= new File(picturePath); ByteArrayOutputStream bos = compressBitmap.getBitmap(); bytes = bos.toByteArray(); base64 = Base64.encodeToString(bytes, Base64.DEFAULT); return base64; // send base64 String on server }
解决方案Missing seems:
options.inPreferQualityOverSpeed = true;
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