diff --git a/content/posts/2023-04.md b/content/posts/2023-04.md index 3a70bcbb1..7491c64df 100644 --- a/content/posts/2023-04.md +++ b/content/posts/2023-04.md @@ -469,14 +469,14 @@ $ psql -d dspace -c "update bundle set primary_bitstream_id=NULL where primary_b | | Q75 | Q80 | Q92 | |------|-----|-----|-----| -| JPEG | 70 | 73 | 88 | -| WebP | 73 | 76 | 82 | -| AVIF | 82 | 83 | 92 | +| JPEG | 71 | 74 | 88 | +| WebP | 74 | 77 | 82 | +| AVIF | 82 | 83 | 86 | - Then I checked the quality and file size (bytes) needed to hit an average ssimulacra2 score of 80 with each format: - - **JPEG**: Q89, 124596 bytes - - **WebP**: Q88, 84935 bytes (32% smaller than JPEG size) - - **AVIF**: Q62, 60347 bytes (52% smaller than JPEG size) + - **JPEG**: Q89, 124923 bytes + - **WebP**: Q86, 84662 bytes (33% smaller than JPEG size) + - **AVIF**: Q65, 67597 bytes (56% smaller than JPEG size) - [Google's original WebP study](https://developers.google.com/speed/webp/docs/webp_study) uses this technique to compare WebP to JPEG too - As the quality settings are not comparable between formats, we need to compare the formats at matching perceptual scores (ssimulacra2 in this case) - I used a ssimulacra2 score of 80 because that's the about the highest score I see with WebP using my samples, though JPEG and AVIF do go higher