How to compress image size?

2019-01-06 17:14发布

I want to capture image in low resolution using android camera api but when I captured image it will take default resolution of device camera.So I want to capture image in low resolution or small size at time of capture or how can I compress big image into small size in android?

12条回答
欢心
2楼-- · 2019-01-06 17:48

Just you try this one

byte[] data = null;
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bi.compress(Bitmap.CompressFormat.JPEG, 100, baos);
    data = baos.toByteArray();
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成全新的幸福
3楼-- · 2019-01-06 17:48

i resolve this problem in this way, later i will improve the code

protected Void doInBackground(byte[]... data) {
        FileOutputStream outStream = null;

        // Write to Internal Storage
        try {
            File dir = new File (context.getFilesDir());
            dir.mkdirs();

            String fileName ="image.jpg";
            File outFile = new File(dir, fileName);
            outFile.setExecutable(true, false);
            outFile.setWritable(true, false);
            outStream = new FileOutputStream(outFile);
            outStream.write(data[0]);
            outStream.flush();
            outStream.close();
            InputStream in = new FileInputStream(context.getFilesDir()+"image.jpg");
            Bitmap bm2 = BitmapFactory.decodeStream(in);
            OutputStream stream = new FileOutputStream(String.valueOf(context.getFilesDir()+pathImage+"/"+idPicture+".jpg"));
            bm2.compress(Bitmap.CompressFormat.JPEG, 50, stream);
            stream.close();
            in.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }
        return null;
    }
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贼婆χ
4楼-- · 2019-01-06 17:51

Try this is working great with me.

private String decodeFile(String path) {
        String strMyImagePath = null;
        Bitmap scaledBitmap = null;

        try {
            // Part 1: Decode image
            Bitmap unscaledBitmap = ScalingUtilities.decodeFile(path, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

            if (!(unscaledBitmap.getWidth() <= 800 && unscaledBitmap.getHeight() <= 800)) {
                // Part 2: Scale image
                scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);
            } else {
                unscaledBitmap.recycle();
                return path;
            }

            // Store to tmp file

            String extr = Environment.getExternalStorageDirectory().toString();
            File mFolder = new File(extr + "/myTmpDir");
            if (!mFolder.exists()) {
                mFolder.mkdir();
            }

            String s = "tmp.png";

            File f = new File(mFolder.getAbsolutePath(), s);

            strMyImagePath = f.getAbsolutePath();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(f);
                scaledBitmap.compress(Bitmap.CompressFormat.PNG, 70, fos);
                fos.flush();
                fos.close();
            } catch (FileNotFoundException e) {

                e.printStackTrace();
            } catch (Exception e) {

                e.printStackTrace();
            }

            scaledBitmap.recycle();
        } catch (Throwable e) {
        }

        if (strMyImagePath == null) {
            return path;
        }
        return strMyImagePath;

    }

Utility Class

public class ScalingUtilities {

    /**
     * Utility function for decoding an image resource. The decoded bitmap will
     * be optimized for further scaling to the requested destination dimensions
     * and scaling logic.
     *
     * @param res The resources object containing the image data
     * @param resId The resource id of the image data
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Decoded bitmap
     */
    public static Bitmap decodeResource(Resources res, int resId, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeResource(res, resId, options);

        return unscaledBitmap;
    }
    public static Bitmap decodeFile(String path, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeFile(path, options);

        return unscaledBitmap;
    }

    /**
     * Utility function for creating a scaled version of an existing bitmap
     *
     * @param unscaledBitmap Bitmap to scale
     * @param dstWidth Wanted width of destination bitmap
     * @param dstHeight Wanted height of destination bitmap
     * @param scalingLogic Logic to use to avoid image stretching
     * @return New scaled bitmap object
     */
    public static Bitmap createScaledBitmap(Bitmap unscaledBitmap, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Rect srcRect = calculateSrcRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Rect dstRect = calculateDstRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Bitmap scaledBitmap = Bitmap.createBitmap(dstRect.width(), dstRect.height(),
                Config.ARGB_8888);
        Canvas canvas = new Canvas(scaledBitmap);
        canvas.drawBitmap(unscaledBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));

        return scaledBitmap;
    }

    /**
     * ScalingLogic defines how scaling should be carried out if source and
     * destination image has different aspect ratio.
     *
     * CROP: Scales the image the minimum amount while making sure that at least
     * one of the two dimensions fit inside the requested destination area.
     * Parts of the source image will be cropped to realize this.
     *
     * FIT: Scales the image the minimum amount while making sure both
     * dimensions fit inside the requested destination area. The resulting
     * destination dimensions might be adjusted to a smaller size than
     * requested.
     */
    public static enum ScalingLogic {
        CROP, FIT
    }

    /**
     * Calculate optimal down-sampling factor given the dimensions of a source
     * image, the dimensions of a destination area and a scaling logic.
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal down scaling sample size for decoding
     */
    public static int calculateSampleSize(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcWidth / dstWidth;
            } else {
                return srcHeight / dstHeight;
            }
        } else {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcHeight / dstHeight;
            } else {
                return srcWidth / dstWidth;
            }
        }
    }

    /**
     * Calculates source rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal source rectangle
     */
    public static Rect calculateSrcRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.CROP) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                final int srcRectWidth = (int)(srcHeight * dstAspect);
                final int srcRectLeft = (srcWidth - srcRectWidth) / 2;
                return new Rect(srcRectLeft, 0, srcRectLeft + srcRectWidth, srcHeight);
            } else {
                final int srcRectHeight = (int)(srcWidth / dstAspect);
                final int scrRectTop = (int)(srcHeight - srcRectHeight) / 2;
                return new Rect(0, scrRectTop, srcWidth, scrRectTop + srcRectHeight);
            }
        } else {
            return new Rect(0, 0, srcWidth, srcHeight);
        }
    }

    /**
     * Calculates destination rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal destination rectangle
     */
    public static Rect calculateDstRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return new Rect(0, 0, dstWidth, (int)(dstWidth / srcAspect));
            } else {
                return new Rect(0, 0, (int)(dstHeight * srcAspect), dstHeight);
            }
        } else {
            return new Rect(0, 0, dstWidth, dstHeight);
        }
    }

}
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霸刀☆藐视天下
5楼-- · 2019-01-06 17:51

I think you are asking about Shrinking image size:

    public Bitmap ShrinkBitmap(String file, int width, int height)
{
    BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
    bmpFactoryOptions.inJustDecodeBounds = true;
    Bitmap bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);

    int heightRatio = (int) Math.ceil(bmpFactoryOptions.outHeight / (float) height);
    int widthRatio = (int) Math.ceil(bmpFactoryOptions.outWidth / (float) width);

    if(heightRatio > 1 || widthRatio > 1)
    {
        if(heightRatio > widthRatio)
        {
            bmpFactoryOptions.inSampleSize = heightRatio;
        }
        else
        {
            bmpFactoryOptions.inSampleSize = widthRatio;
        }
    }

    bmpFactoryOptions.inJustDecodeBounds = false;
    bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);
    return bitmap;
}
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Deceive 欺骗
6楼-- · 2019-01-06 17:56

You can create bitmap with captured image as below:

Bitmap bitmap = Bitmap.createScaledBitmap(capturedImage, width, height, true);

Here you can specify width and height of the bitmap that you want to set to your ImageView. The height and width you can set according to the screen dpi of the device also, by reading the screen dpi of different devices programmatically.

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smile是对你的礼貌
7楼-- · 2019-01-06 17:59

You can try this code

    public class ScalingUtilities {

    /**
     * Utility function for decoding an image resource. The decoded bitmap will
     * be optimized for further scaling to the requested destination dimensions
     * and scaling logic.
     *
     * @param res The resources object containing the image data
     * @param resId The resource id of the image data
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Decoded bitmap
     */
    public static Bitmap decodeResource(Resources res, int resId, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeResource(res, resId, options);

        return unscaledBitmap;
    }
    public static Bitmap decodeFile(String path, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeFile(path, options);

        return unscaledBitmap;
    }

    /**
     * Utility function for creating a scaled version of an existing bitmap
     *
     * @param unscaledBitmap Bitmap to scale
     * @param dstWidth Wanted width of destination bitmap
     * @param dstHeight Wanted height of destination bitmap
     * @param scalingLogic Logic to use to avoid image stretching
     * @return New scaled bitmap object
     */
    public static Bitmap createScaledBitmap(Bitmap unscaledBitmap, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Rect srcRect = calculateSrcRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Rect dstRect = calculateDstRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Bitmap scaledBitmap = Bitmap.createBitmap(dstRect.width(), dstRect.height(),
                Config.ARGB_8888);
        Canvas canvas = new Canvas(scaledBitmap);
        canvas.drawBitmap(unscaledBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));

        return scaledBitmap;
    }

    /**
     * ScalingLogic defines how scaling should be carried out if source and
     * destination image has different aspect ratio.
     *
     * CROP: Scales the image the minimum amount while making sure that at least
     * one of the two dimensions fit inside the requested destination area.
     * Parts of the source image will be cropped to realize this.
     *
     * FIT: Scales the image the minimum amount while making sure both
     * dimensions fit inside the requested destination area. The resulting
     * destination dimensions might be adjusted to a smaller size than
     * requested.
     */
    public static enum ScalingLogic {
        CROP, FIT
    }

    /**
     * Calculate optimal down-sampling factor given the dimensions of a source
     * image, the dimensions of a destination area and a scaling logic.
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal down scaling sample size for decoding
     */
    public static int calculateSampleSize(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcWidth / dstWidth;
            } else {
                return srcHeight / dstHeight;
            }
        } else {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcHeight / dstHeight;
            } else {
                return srcWidth / dstWidth;
            }
        }
    }

    /**
     * Calculates source rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal source rectangle
     */
    public static Rect calculateSrcRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.CROP) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                final int srcRectWidth = (int)(srcHeight * dstAspect);
                final int srcRectLeft = (srcWidth - srcRectWidth) / 2;
                return new Rect(srcRectLeft, 0, srcRectLeft + srcRectWidth, srcHeight);
            } else {
                final int srcRectHeight = (int)(srcWidth / dstAspect);
                final int scrRectTop = (int)(srcHeight - srcRectHeight) / 2;
                return new Rect(0, scrRectTop, srcWidth, scrRectTop + srcRectHeight);
            }
        } else {
            return new Rect(0, 0, srcWidth, srcHeight);
        }
    }

    /**
     * Calculates destination rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal destination rectangle
     */
    public static Rect calculateDstRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return new Rect(0, 0, dstWidth, (int)(dstWidth / srcAspect));
            } else {
                return new Rect(0, 0, (int)(dstHeight * srcAspect), dstHeight);
            }
        } else {
            return new Rect(0, 0, dstWidth, dstHeight);
        }
    }


    public static String decodeFile(String path,int DESIREDWIDTH, int DESIREDHEIGHT, int type) {
        String strMyImagePath = null;
        Bitmap scaledBitmap = null;
        Bitmap rotated = null;

        try {
            // Part 1: Decode image
            Bitmap unscaledBitmap = ScalingUtilities.decodeFile(path, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

//            if (!(unscaledBitmap.getWidth() <= DESIREDWIDTH && unscaledBitmap.getHeight() <= DESIREDHEIGHT)) {
//                // Part 2: Scale image
//                scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);
//            } else {
//                unscaledBitmap.recycle();
//                return path;
//            }

            // Store to tmp file
            scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

            String extr = Environment.getExternalStorageDirectory().toString();
            File mFolder = new File(extr + com.vt.vsmart.utils.Config.SD_PATH+"/image");
            if (!mFolder.exists()) {
                mFolder.mkdir();
            }

            String s = type+"temp.jpg";

            File f = new File(mFolder.getAbsolutePath(), s);

            strMyImagePath = f.getAbsolutePath();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(f);
//                scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 95, fos);

                // quay anh 90 do
                Matrix matrix = new Matrix();

                matrix.postRotate(90);

                rotated = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true);

                rotated.compress(Bitmap.CompressFormat.JPEG, 95, fos);

                fos.flush();
                fos.close();
            } catch (FileNotFoundException e) {

                e.printStackTrace();
            } catch (Exception e) {

                e.printStackTrace();
            }

//            scaledBitmap.recycle();
            rotated.recycle();
        } catch (Throwable e) {
        }

        if (strMyImagePath == null) {
            return path;
        }
        return strMyImagePath;

    }

    // check anh bi quay
    public int getCameraPhotoOrientation(Context context, Uri imageUri, String imagePath){
        int rotate = 0;
        try {
            context.getContentResolver().notifyChange(imageUri, null);
            File imageFile = new File(imagePath);

            ExifInterface exif = new ExifInterface(imageFile.getAbsolutePath());
            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

            switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_270:
                rotate = 270;
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                rotate = 180;
                break;
            case ExifInterface.ORIENTATION_ROTATE_90:
                rotate = 90;
                break;
            }

//            Log.i("RotateImage", "Exif orientation: " + orientation);
//            Log.i("RotateImage", "Rotate value: " + rotate);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rotate;
    }

}

It work for me. I hope it can hepl you!

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