如何做一个大尺寸的位图图像处理没有崩溃 [英] How to do image processing on a big size bitmap without crashing

问题描述

我想加载一个大尺寸（约10 MB）的图像，让用户添加一些效果（如灰度等）。所以，我用装 inSampleSize 位图来显示preVIEW用户：

I want to load a big size (about 10 MB) image and let user add some effects (such as Grayscale and so on). So, I loaded the bitmap using inSampleSize to show a preview to user:

public Bitmap load(Context context, int[] holderDimention, String image_url) throws Exception {
    BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
    bitmapOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(image_url, bitmapOptions);

    int inSampleSize = 1;

    final int outWidth = bitmapOptions.outWidth;
    final int outHeight = bitmapOptions.outHeight;

    final int holderWidth = holderDimention[0];
    final int holderHeight = holderDimention[1];

    // Calculation inSampleSize
    if (outHeight > holderHeight || outWidth > holderWidth) {
        final int halfWidth = outWidth / 2;
        final int halfHeight = outHeight / 2;

        while ((halfHeight / inSampleSize) > holderHeight && (halfWidth / inSampleSize) > holderWidth) {
            inSampleSize *= 2;
        }
    }

    bitmapOptions.inSampleSize = inSampleSize;

    // Decoding bitmap
    bitmapOptions.inJustDecodeBounds = false;
    return BitmapFactory.decodeFile(image_url, bitmapOptions);
}

最后，在背景我想不降采样（它是必要的）施加在原始图像上的影响。所以我用下面的code的子类中，的AsyncTask ：

public Bitmap load(Context context, String image_url) throws IOException {
    return BitmapFactory.decodeFile(image_url);
}

但我得到一个内存不足的异常。我怎么能解决这个问题？

But I got an out of memory exception. How could I handle this problem?

推荐答案

您需要部分地做到这一点。仅加载图像，过程的一部分，保存部分。请查看 Bitma pregionDe codeR 。

You need to do it partially. Load only part of the image, process, save part. Check out BitmapRegionDecoder.

相关问题：没有加载到内存中

Related question: Crop image without loading into memory

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