如何在 Flutter MultiImagePicker 中指定照片的質量？ (How can i specify the quality of the photo in Flutter MultiImagePicker?)

問題描述

如何在 Flutter MultiImagePicker 中指定照片的質量？ (How can i specify the quality of the photo in Flutter MultiImagePicker?)

我需要上傳一些照片並將這些照片發送到數據庫。由於照片質量很高，完成和上傳每張照片需要相當長的時間。我不需要非常高質量的照片，所以我需要壓縮照片。如果我使用 Flutter MultiImagePicker 類，最好的解決方案是什麼？

List<Asset> pickedImagesList = await MultiImagePicker.pickImages(maxImages: 25, enableCamera: false);

參考解法

方法 1:

Your package already propose a few options to compress an Asset object.

List<Asset> pickedImagesList = await MultiImagePicker.pickImages(maxImages: 25, enableCamera: false);
for (Asset asset in pickedImagesList) {
   ByteData assetData = await asset.getThumbByteData(
      width: // desired width,
      height: // desired height,
      quality: //desired quality,
   );
   // Send assetData to your database
}

EDIT

I think this could work to keep your aspect ratio:

double getAspectRatio(double originalSize, double desiredSize) => desiredSize / originalSize;

final aspectRatio = getAspectRatio(asset.originalWidth, imageDesiredWidth);
ByteData assetData = await asset.getThumbByteData(
   width: (asset.originalWidth * aspectRatio).round(),
   height: (asset.originalHeight * aspectRatio).round(),
   quality: //desired quality,
);

方法 2:

If you want to use the original width and height without any manipulate use

getByteData(quality: 80)

instead

getThumbByteData(quality: 80)

(by Sergei Eensalu、Guillaume Roux、Abdalla)

參考文件

1. How can i specify the quality of the photo in Flutter MultiImagePicker? (CC BY‑SA 2.5/3.0/4.0)