我使用这种方法来压缩图像
if(bitmapObject.compress(Bitmap.CompressFormat.PNG, 100, fOut))
{
...
}
但是我得到的图像在压缩后尺寸变小了。
我的应用程序需要通过网络发送压缩后的图像——所以我希望尽可能地减少数据量……但我必须保持图像的原始大小。
有没有其他方法可以在进行压缩的同时保持原始位图尺寸?
我使用这种方法来压缩图像
if(bitmapObject.compress(Bitmap.CompressFormat.PNG, 100, fOut))
{
...
}
但是我得到的图像在压缩后尺寸变小了。
我的应用程序需要通过网络发送压缩后的图像——所以我希望尽可能地减少数据量……但我必须保持图像的原始大小。
有没有其他方法可以在进行压缩的同时保持原始位图尺寸?
你确定它更小吗?
Bitmap original = BitmapFactory.decodeStream(getAssets().open("1024x768.jpg"));
ByteArrayOutputStream out = new ByteArrayOutputStream();
original.compress(Bitmap.CompressFormat.PNG, 100, out);
Bitmap decoded = BitmapFactory.decodeStream(new ByteArrayInputStream(out.toByteArray()));
Log.e("Original dimensions", original.getWidth()+" "+original.getHeight());
Log.e("Compressed dimensions", decoded.getWidth()+" "+decoded.getHeight());
给出。12-07 17:43:36.333: E/Original dimensions(278): 1024 768
12-07 17:43:36.333: E/Compressed dimensions(278): 1024 768
也许您从资源中获取位图,在这种情况下,位图的尺寸将取决于手机屏幕密度。Bitmap bitmap=((BitmapDrawable)getResources().getDrawable(R.drawable.img_1024x768)).getBitmap();
Log.e("Dimensions", bitmap.getWidth()+" "+bitmap.getHeight());
12-07 17:43:38.733: E/Dimensions(278): 768 576
ImageView imageView = (ImageView)findViewById(R.id.imageView);
Bitmap bitmap = ImageUtils.getInstant().getCompressedBitmap("Your_Image_Path_Here");
imageView.setImageBitmap(bitmap);
ImageUtils.java:
public class ImageUtils {
public static ImageUtils mInstant;
public static ImageUtils getInstant(){
if(mInstant==null){
mInstant = new ImageUtils();
}
return mInstant;
}
public Bitmap getCompressedBitmap(String imagePath) {
float maxHeight = 1920.0f;
float maxWidth = 1080.0f;
Bitmap scaledBitmap = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory.decodeFile(imagePath, options);
int actualHeight = options.outHeight;
int actualWidth = options.outWidth;
float imgRatio = (float) actualWidth / (float) actualHeight;
float maxRatio = maxWidth / maxHeight;
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(imagePath, 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));
ExifInterface exif = null;
try {
exif = new ExifInterface(imagePath);
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 0);
Matrix matrix = new Matrix();
if (orientation == 6) {
matrix.postRotate(90);
} else if (orientation == 3) {
matrix.postRotate(180);
} else if (orientation == 8) {
matrix.postRotate(270);
}
scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true);
} catch (IOException e) {
e.printStackTrace();
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 85, out);
byte[] byteArray = out.toByteArray();
Bitmap updatedBitmap = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
return updatedBitmap;
}
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;
}
}
在压缩位图后,其尺寸保持不变。
我是如何检查的?
Bitmap beforeBitmap = BitmapFactory.decodeFile("Your_Image_Path_Here");
Log.i("Before Compress Dimension", beforeBitmap.getWidth()+"-"+beforeBitmap.getHeight());
Bitmap afterBitmap = ImageUtils.getInstant().getCompressedBitmap("Your_Image_Path_Here");
Log.i("After Compress Dimension", afterBitmap.getWidth() + "-" + afterBitmap.getHeight());
输出:
Before Compress : Dimension: 1080-1452
After Compress : Dimension: 1080-1452
希望这可以帮到你。
以下是我用来缩小高字节计数(即像素)的图像大小的简短方法:
fun resizeImage(image: Bitmap): Bitmap {
val width = image.width
val height = image.height
val scaleWidth = width / 10
val scaleHeight = height / 10
if (image.byteCount <= 1000000)
return image
return Bitmap.createScaledBitmap(image, scaleWidth, scaleHeight, false)
}
此方法返回一个比传入参数Bitmap
小10倍以上的缩放后的图片。可能不是最理想的解决方案,但它可行。
public Bitmap compress(Bitmap yourBitmap){
//converted into webp into lowest quality
ByteArrayOutputStream stream = new ByteArrayOutputStream();
yourBitmap.compress(Bitmap.CompressFormat.WEBP,0,stream);//0=lowest, 100=highest quality
byte[] byteArray = stream.toByteArray();
//convert your byteArray into bitmap
Bitmap yourCompressBitmap = BitmapFactory.decodeByteArray(byteArray,0,byteArray.length);
return yourCompressBitmap;
}
这一切都是在不失去图像尺寸的情况下完成的。
如果有任何问题,请在下面评论。
我认为你使用这种方法来压缩位图
BitmapFactory.Option imageOpts = new BitmapFactory.Options ();
imageOpts.inSampleSize = 2; // for 1/2 the image to be loaded
Bitmap thumb = Bitmap.createScaledBitmap (BitmapFactory.decodeFile(photoPath, imageOpts), 96, 96, false);
original.compress(Bitmap.CompressFormat.PNG, 100, out);
- Apurva