Android的：调整位图不失品质 [英] Android: Resizing Bitmaps without losing quality

问题描述

我真的寻遍了整个网络，然后再发布。我的问题是，我不能不失图像的质量（质量实在是太差和像素化）调整位图。

i've really searched through over the entire web before posting. My problem is that i cannot resize bitmap without losing the quality of the image (the quality is really bad and pixelated).

我把位图从相机，然后我必须为下限值，所以我可以把它上传到服务器快多了。

I take the bitmap from camera and then i have to downscale it, so i can upload it to the server much faster.

这是做采样功能

public Bitmap resizeBitmap(Bitmap bitmap){
         Canvas canvas = new Canvas();
         Bitmap resizedBitmap = null;
         if (bitmap !=null) {
                int h = bitmap.getHeight();
                int w = bitmap.getWidth();
                int newWidth=0;
                int newHeight=0;

                if(h>w){
                    newWidth = 600;
                    newHeight = 800;
                }

                if(w>h){
                    newWidth = 800;
                    newHeight = 600;
                    }

                float scaleWidth = ((float) newWidth) / w;
                float scaleHeight = ((float) newHeight) / h;



                Matrix matrix = new Matrix();
                // resize the bit map
                matrix.preScale(scaleWidth, scaleHeight);

                resizedBitmap  = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);



                Paint paint = new Paint();
                paint.setAntiAlias(true);
                paint.setFilterBitmap(true);
                paint.setDither(true);

                canvas.drawBitmap(resizedBitmap, matrix, paint);



            }


        return resizedBitmap;   

和我这是怎么从活动的结果所得到的图像

and this is how i get the image from activity result

 protected void onActivityResult(int requestCode, int resultCode,
             Intent data) {
         if(resultCode != RESULT_CANCELED){

         if (requestCode == 0) {
             if (resultCode == RESULT_OK) {


                    getContentResolver().notifyChange(mImageUri, null);
                    ContentResolver cr = this.getContentResolver();

                    try
                    {
                        b = android.provider.MediaStore.Images.Media.getBitmap(cr, mImageUri);
                        Log.d("foto", Integer.toString(b.getWidth()));
                        Log.d("foto", Integer.toString(b.getHeight()));
                        addPhoto.setImageBitmap(b);

                    }
                    catch (Exception e)
                    {
                        Toast.makeText(this, "Failed to load", Toast.LENGTH_SHORT).show();
                        Log.d("TAG", "Failed to load", e);
                    }



             }
         }

我开始认为，要得到一个小图片尺寸的最佳方式是设置摄像头分辨率。任何人都可以帮忙吗？

I'm starting to think that the best way to get a small picture size is to set the camera resolution. Anyone else can help?

推荐答案

尝试<一个href=\"http://developer.android.com/reference/android/graphics/Bitmap.html#createScaledBitmap%28android.graphics.Bitmap,%20int,%20int,%20boolean%29\"相对=nofollow> Bitmap.createScaledBitmap 。
它也有一个选项，以筛选源。

Try Bitmap.createScaledBitmap. It also has an option to filter the source.

这篇关于Android的：调整位图不失品质的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！