c2pa-rs

commit b167baeb3faa78f3a5b9f0e7cf6e197b81ac095b
parent d402e9a855d6e5366000eea2f841119258c2c5ad
Author: Gavin  Peacock <gpeacock@adobe.com>
Date:   Thu,  6 Oct 2022 13:47:19 -0700

create jpeg thumbnails for pngs without alpha (#145)


Diffstat:
M
sdk/src/utils/thumbnail.rs
 | 
5
++---

1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/sdk/src/utils/thumbnail.rs b/sdk/src/utils/thumbnail.rs
@@ -31,11 +31,10 @@ pub fn make_thumbnail(path: &std::path::Path) -> Result<(String, Vec<u8>)> {
     if img.width() > longest_edge || img.height() > longest_edge {
         img = img.thumbnail(longest_edge, longest_edge);
     }
-
-    // for png files, use png thumbnails for transparency
+    // for png files, use png thumbnails if there is an alpha channel
     // for other supported types try a jpeg thumbnail
     let (output_format, content_type) = match format {
-        ImageFormat::Png => (image::ImageOutputFormat::Png, "image/png"),
+        ImageFormat::Png if img.color().has_alpha() => (image::ImageOutputFormat::Png, "image/png"),
         _ => (
             image::ImageOutputFormat::Jpeg(THUMBNAIL_JPEG_QUALITY),
             "image/jpeg",