fluffychat/lib/utils/resize_image.dart
Krille Fear 00daabf17c fix: Better thumbnails
This checks if the image is png or
jpg and therefore doesnt remove
transparancy. It also encodes
thumbnails with higher resolution
to make them less ugly.
2021-12-12 12:03:58 +01:00

80 lines
2.1 KiB
Dart

//@dart=2.12
import 'dart:math' as math;
import 'dart:typed_data';
import 'package:flutter/foundation.dart';
import 'package:blurhash_dart/blurhash_dart.dart';
import 'package:image/image.dart';
import 'package:matrix/matrix.dart';
extension ResizeImage on MatrixFile {
static const int max = 1200;
static const int quality = 40;
Future<MatrixImageFile> resizeImage({
bool calcBlurhash = true,
int max = ResizeImage.max,
int quality = ResizeImage.quality,
}) async {
final bytes = mimeType == 'image/gif'
? this.bytes
: await compute<_ResizeBytesConfig, Uint8List>(
resizeBytes,
_ResizeBytesConfig(
bytes: this.bytes,
mimeType: mimeType,
max: max,
quality: quality,
));
final blurhash = calcBlurhash
? await compute<Uint8List, BlurHash>(createBlurHash, bytes)
: null;
return MatrixImageFile(
bytes: bytes,
name: '${name.split('.').first}_thumbnail_$max.jpg',
blurhash: blurhash?.hash,
);
}
}
Future<BlurHash> createBlurHash(Uint8List file) async {
final image = decodeImage(file)!;
return BlurHash.encode(image, numCompX: 4, numCompY: 3);
}
Future<Uint8List> resizeBytes(_ResizeBytesConfig config) async {
var image = decodeImage(config.bytes)!;
// Is file already smaller than max? Then just return.
if (math.max(image.width, image.height) > config.max) {
// Use the larger side to resize.
final useWidth = image.width >= image.height;
image = useWidth
? copyResize(image, width: config.max)
: copyResize(image, height: config.max);
}
const pngMimeType = 'image/png';
final encoded = config.mimeType.toLowerCase() == pngMimeType
? encodePng(image)
: encodeJpg(image, quality: config.quality);
return Uint8List.fromList(encoded);
}
class _ResizeBytesConfig {
final Uint8List bytes;
final int max;
final int quality;
final String mimeType;
const _ResizeBytesConfig({
required this.bytes,
this.max = ResizeImage.max,
this.quality = ResizeImage.quality,
required this.mimeType,
});
}