[BUG] Zoom out the image will generate mosaic

Aoi-hosizora commented 4 years ago

Describe the bug

I zoom out an image that is in the disk. But If the photo is small, it will generate mosaic when zoom in to a larger size. And if the photo is large, it will be sharpened when zoom out to a smaller size. That is, the quality is low.

To Reproduce

There is my code:

PhotoViewGallery.builder(
  scrollPhysics: BouncingScrollPhysics(),
  backgroundDecoration: BoxDecoration(color: Colors.black),
  loadFailedChild: Center(
    child: Icon(Icons.broken_image),
  ),
  onPageChanged: _onPageChanged,
  pageController: _controller,
  itemCount: widget.images.length,
  builder: (BuildContext context, int index) => PhotoViewGalleryPageOptions(
    imageProvider: LocalOrNetworkImageProvider( // customer provider
      url: widget.images[index],
      file: () async {
        var url = widget.images[index];
        var path = await getDownloadItemPath(id: widget.id, categoryId: widget.categoryId);
        path = '$path/${url.split('/').last}';
        return File(path);
      },
    ),
    initialScale: PhotoViewComputedScale.contained,
    minScale: PhotoViewComputedScale.contained / 2,
    maxScale: PhotoViewComputedScale.covered * 2,
    heroAttributes: PhotoViewHeroAttributes(tag: widget.images[index]),
  ),
),

Screenshots

Image from PhotoViewGallery (small photo zoom in)