Question

我目前正在关注this site的教程来压缩我的图片。它在一些手机上运行得非常好，例如LG G3，Moto G和一些三星机型。但是，对于某些手机，例如Xiomi Mi4，它会在此线路上导致内存不足错误。

options.inTempStorage = new byte[16 * 1024];

整个代码如下 -

public Bitmap compressImage(String imageLocation) {
    Bitmap scaledBitmap = null;

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    Bitmap bmp = BitmapFactory.decodeFile(imageLocation, options);

    int actualHeight = options.outHeight;
    int actualWidth = options.outWidth;
    float maxHeight = 700.0f;//816.0f;
    float maxWidth = 500.0f; //612.0f;
    float imgRatio = actualWidth / 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 = utils.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(imageLocation, 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;
    try {
        exif = new ExifInterface(imageLocation);

        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;
}

有人可以帮助我/提出如何改进此代码的建议，以便减少内存。

Answer 1

您正在处理大型位图并在运行时加载所有这些位图时间。您必须通过加载非常仔细地处理大位图您需要的大小不是整个位图，而是一次缩放。

请查看以下链接

Is it possible to catch out of memory exception in java?

Answer 2

您应根据所需尺寸设置样本量。尝试设置 options.inSampleSize动态。即

{% for entity in entities %}
    .
    .
    <td>{{ entity.getCategory().getName() }}</td>
    .
{% endfor %}

//方法

options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

图像压缩期间内存不足错误

2 个答案: