android图片压缩并转为base64字符串

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.util.Base64;import android.util.Log;import java.io.ByteArrayOutputStream;import java.io.IOException;public class PicUtil {    public static String compressImage(String filePath, String type) {        Bitmap scaledBitmap = null;        BitmapFactory.Options options = new BitmapFactory.Options();//      by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If//      you try the use the bitmap here, you will get null.        options.inJustDecodeBounds = true;        Bitmap bmp = BitmapFactory.decodeFile(filePath, options);        int actualHeight = options.outHeight;        int actualWidth = options.outWidth;//      max Height and width values of the compressed image is taken as 816x612        float maxHeight = 816.0f;        float maxWidth = 612.0f;        float imgRatio = actualWidth / actualHeight;        float maxRatio = maxWidth / maxHeight;//      width and height values are set maintaining the aspect ratio of the image        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;            }        }//      setting inSampleSize value allows to load a scaled down version of the original image        options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);//      inJustDecodeBounds set to false to load the actual bitmap        options.inJustDecodeBounds = false;//      this options allow android to claim the bitmap memory if it runs low on memory        options.inPurgeable = true;        options.inInputShareable = true;        options.inTempStorage = new byte[16 * 1024];        try {//          load the bitmap from its path            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));//      check the rotation of the image and display it properly        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();        }         ByteArrayOutputStream baos = new ByteArrayOutputStream();        if (type.toLowerCase().contains("png")) {            scaledBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);        } else {            scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);        }        byte[] datas = baos.toByteArray();        Log.e("size", (datas.length / 1024) + "");        return Base64.encodeToString(datas,Base64.DEFAULT);    }    public static 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;    }}

一个工具类，可以使图片压缩最优化。质量优，文件小。3,4M大小一般压缩为400k。

使用方法

var ext="png"val base64Image =  PicUtil.compressImage(pickFile?.absolutePath, ext)

更多相关文章

随机推荐