18

我希望我的代码在保存之前调整图像大小，但我在 Google 上找不到任何相关信息。请问你能帮帮我吗 ？

这是代码（来自 Android 文档）：

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent("android.intent.action.MEDIA_SCANNER_SCAN_FILE");
    File f = new File(mCurrentPhotoPath);

    picturePathForUpload = mCurrentPhotoPath;

    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

之后，我必须将其上传到服务器。

非常感谢。

4

6 回答 6

28

您可以按照以下代码保存位图图像

Bitmap photo = (Bitmap) "your Bitmap image";
photo = Bitmap.createScaledBitmap(photo, 100, 100, false);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
photo.compress(Bitmap.CompressFormat.JPEG, 40, bytes);

File f = new File(Environment.getExternalStorageDirectory()
        + File.separator + "Imagename.jpg");
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.close();
于 2013-04-17T14:28:46.333 回答
6

在阅读了其他答案并没有找到我想要的东西之后，这是我获取适当​​缩放位图的方法。这是对 Prabu 答案的改编。

它确保您的图片以不会使照片尺寸变形的方式缩放：

public saveScaledPhotoToFile() {
    //Convert your photo to a bitmap
    Bitmap photoBm = (Bitmap) "your Bitmap image";
    //get its orginal dimensions
    int bmOriginalWidth = photoBm.getWidth();
    int bmOriginalHeight = photoBm.getHeight();
    double originalWidthToHeightRatio =  1.0 * bmOriginalWidth / bmOriginalHeight;
    double originalHeightToWidthRatio =  1.0 * bmOriginalHeight / bmOriginalWidth;
    //choose a maximum height
    int maxHeight = 1024;
    //choose a max width
    int maxWidth = 1024;
    //call the method to get the scaled bitmap
    photoBm = getScaledBitmap(photoBm, bmOriginalWidth, bmOriginalHeight,
            originalWidthToHeightRatio, originalHeightToWidthRatio,
            maxHeight, maxWidth);

    /**********THE REST OF THIS IS FROM Prabu's answer*******/
    //create a byte array output stream to hold the photo's bytes
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    //compress the photo's bytes into the byte array output stream
    photoBm.compress(Bitmap.CompressFormat.JPEG, 40, bytes);

    //construct a File object to save the scaled file to
    File f = new File(Environment.getExternalStorageDirectory()
            + File.separator + "Imagename.jpg");
    //create the file
    f.createNewFile();

    //create an FileOutputStream on the created file
    FileOutputStream fo = new FileOutputStream(f);
    //write the photo's bytes to the file
    fo.write(bytes.toByteArray());

    //finish by closing the FileOutputStream
    fo.close();
}

private static Bitmap getScaledBitmap(Bitmap bm, int bmOriginalWidth, int bmOriginalHeight, double originalWidthToHeightRatio, double originalHeightToWidthRatio, int maxHeight, int maxWidth) {
    if(bmOriginalWidth > maxWidth || bmOriginalHeight > maxHeight) {
        Log.v(TAG, format("RESIZING bitmap FROM %sx%s ", bmOriginalWidth, bmOriginalHeight));

        if(bmOriginalWidth > bmOriginalHeight) {
            bm = scaleDeminsFromWidth(bm, maxWidth, bmOriginalHeight, originalHeightToWidthRatio);
        } else {
            bm = scaleDeminsFromHeight(bm, maxHeight, bmOriginalHeight, originalWidthToHeightRatio);
        }

        Log.v(TAG, format("RESIZED bitmap TO %sx%s ", bm.getWidth(), bm.getHeight()));
    }
    return bm;
}

private static Bitmap scaleDeminsFromHeight(Bitmap bm, int maxHeight, int bmOriginalHeight, double originalWidthToHeightRatio) {
    int newHeight = (int) Math.min(maxHeight, bmOriginalHeight * .55);
    int newWidth = (int) (newHeight * originalWidthToHeightRatio);
    bm = Bitmap.createScaledBitmap(bm, newWidth, newHeight, true);
    return bm;
}

private static Bitmap scaleDeminsFromWidth(Bitmap bm, int maxWidth, int bmOriginalWidth, double originalHeightToWidthRatio) {
    //scale the width
    int newWidth = (int) Math.min(maxWidth, bmOriginalWidth * .75);
    int newHeight = (int) (newWidth * originalHeightToWidthRatio);
    bm = Bitmap.createScaledBitmap(bm, newWidth, newHeight, true);
    return bm;
}

这是我的 GitHub Gist 的相应链接：https ://gist.github.com/Lwdthe1/2d1cd0a12f30c18db698

于 2016-03-24T21:57:09.287 回答
5

首先将您的图像转换为位图，然后使用以下代码：

Bitmap yourBitmap;
Bitmap resized = Bitmap.createScaledBitmap(yourBitmap, newWidth, newHeight, true);
于 2013-04-17T12:40:04.767 回答
1

看到这个 会很有帮助。通常，如果您使用意图通过相机拍摄图像，您将获得uri图像，因为您将其读取为按比例缩小的图像并将其存储在同一个地方

于 2013-04-17T12:43:37.660 回答
0

如果要截取完整尺寸的图像，那么您别无选择，只能将其保存到 sd 购物车，然后更改图像的大小。

但是，如果缩略图足够，则无需将其保存到 SD 卡中，您可以从返回的意图的附加内容中提取它。

您可以查看我为使用内置相机拍摄图像的两种方法编写的本指南Activity：

指南：Android：将相机活动用于缩略图和全尺寸图像

于 2013-04-17T14:33:42.493 回答
0 
BitmapFactory.Options optionsSignature = new BitmapFactory.Options();
final Bitmap bitmapSignature = BitmapFactory.decodeFile(
fileUriSignature.getPath(), optionsSignature);
Bitmap resizedSignature = Bitmap.createScaledBitmap(
                bitmapSignature, 256, 128, true);
signature.setImageBitmap(resizedSignature);
于 2016-04-26T04:33:51.143 回答