Android 图片压缩

Android 图片压缩

标签（空格分隔）： Android

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import java.io.ByteArrayOutputStream;
import java.io.File;

import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.util.Base64;

public class PictureUtil {


	/**
	 * 把bitmap转换成String
	 * 
	 * @param filePath
	 * @return
	 */
	public static String bitmapToString(String filePath) {

		Bitmap bm = getSmallBitmap(filePath);
		
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		bm.compress(Bitmap.CompressFormat.JPEG, 40, baos);
		byte[] b = baos.toByteArray();
		
		return Base64.encodeToString(b, Base64.DEFAULT);
		
	}

	/**
	 * 计算图片的缩放值
	 * 
	 * @param options
	 * @param reqWidth
	 * @param reqHeight
	 * @return
	 */
	public static int calculateInSampleSize(BitmapFactory.Options options,
			int reqWidth, int reqHeight) {
		// Raw height and width of image
		final int height = options.outHeight;
		final int width = options.outWidth;
		int inSampleSize = 1;

		if (height > reqHeight || width > reqWidth) {

			// Calculate ratios of height and width to requested height and
			// width
			final int heightRatio = Math.round((float) height
					/ (float) reqHeight);
			final int widthRatio = Math.round((float) width / (float) reqWidth);

			// Choose the smallest ratio as inSampleSize value, this will
			// guarantee
			// a final image with both dimensions larger than or equal to the
			// requested height and width.
			inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
		}

		return inSampleSize;
	}

	

	
	/**
	 * 根据路径获得突破并压缩返回bitmap用于显示
	 * 
	 * @param imagesrc
	 * @return
	 */
	public static Bitmap getSmallBitmap(String filePath) {
		final BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		BitmapFactory.decodeFile(filePath, options);

		// Calculate inSampleSize
		options.inSampleSize = calculateInSampleSize(options, 480, 800);

		// Decode bitmap with inSampleSize set
		options.inJustDecodeBounds = false;

		return BitmapFactory.decodeFile(filePath, options);
	}

	/**
	 * 根据路径删除图片
	 * 
	 * @param path
	 */
	public static void deleteTempFile(String path) {
		File file = new File(path);
		if (file.exists()) {
			file.delete();
		}
	}

	/**
	 * 添加到图库
	 */
	public static void galleryAddPic(Context context, String path) {
		Intent mediaScanIntent = new Intent(
				Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
		File f = new File(path);
		Uri contentUri = Uri.fromFile(f);
		mediaScanIntent.setData(contentUri);
		context.sendBroadcast(mediaScanIntent);
	}

	/**
	 * 获取保存图片的目录
	 * 
	 * @return
	 */
	public static File getAlbumDir() {
		File dir = new File(
				Environment
						.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
				getAlbumName());
		if (!dir.exists()) {
			dir.mkdirs();
		}
		return dir;
	}

	/**
	 * 获取保存 隐患检查的图片文件夹名称
	 * 
	 * @return
	 */
	public static String getAlbumName() {
		return "sheguantong";
	}
}

/* 保存图片 */
 private void saveBitmapToFile(Bitmap bitmap) {
        String url = Environment.getExternalStorageDirectory() + File.separator + "pepelu" + File.separator;
        String filePath2 = url + "2.jpg";
        File file = new File(filePath2);
        // File f = new File(Environment.getExternalStorageDirectory()                 , fileName);
        FileOutputStream fOut = null;
        try {
            file.createNewFile();
            fOut = new FileOutputStream(file);
        } catch (IOException e) {
            e.printStackTrace();
        }
        bitmap.compress(Bitmap.CompressFormat.JPEG, 40, fOut);
        try {
            fOut.flush();
            fOut.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

Context#getFilesDir()