diff --git a/Cargo.toml b/Cargo.toml
index 702a089..a673481 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,3 +40,7 @@ load_image = "2.12.0"
 [[bench]]
 name = "image"
 harness = false
+
+# Build dependencies with release optimizations even in dev mode.
+[profile.dev.package."*"]
+opt-level = 3
diff --git a/src/library.rs b/src/library.rs
index 4a9a806..f531d0b 100644
--- a/src/library.rs
+++ b/src/library.rs
@@ -25,7 +25,7 @@ use rocksdb::IteratorMode;
 use rocksdb::DB;
 
 // Used to ensure DB is invalidated after schema changes.
-const LIBRARY_GENERATION: &'static str = "13";
+const LIBRARY_GENERATION: &'static str = "14";
 
 #[derive(Clone)]
 pub struct Library {
@@ -116,6 +116,25 @@ pub fn resize(
     img: &DynamicImage,
     dimensions: (Option<u32>, Option<u32>),
     filter: FilterType,
+) -> DynamicImage {
+    let (w, h) = dimensions;
+    let (orig_w, orig_h) = img.dimensions();
+    let (w, h) = match (w, h) {
+        (Some(w), Some(h)) => (w, h),
+        (Some(w), None) => (w, orig_h * w / orig_w),
+        (None, Some(h)) => (orig_w * h / orig_h, h),
+        (None, None) => (orig_w, orig_h),
+    };
+    match filter {
+        FilterType::Builtin(filter) => img.resize(w, h, filter),
+        FilterType::Nearest => unimplemented!(), //resize_to_fill_nearest(w, h, img),
+    }
+}
+
+pub fn resize_to_fill(
+    img: &DynamicImage,
+    dimensions: (Option<u32>, Option<u32>),
+    filter: FilterType,
 ) -> DynamicImage {
     let (w, h) = dimensions;
     let (orig_w, orig_h) = img.dimensions();
@@ -261,11 +280,13 @@ impl Library {
     fn generational_key(generation: &str, key: &str) -> String {
         format!("{}/{}", generation, key)
     }
+
     pub fn generate_thumbnail(
         &self,
         media_items_id: &str,
         dimensions: (Option<u32>, Option<u32>),
         filter: FilterType,
+        fill: bool,
     ) -> Result<Vec<u8>, Box<dyn std::error::Error>> {
         match self.original(&media_items_id) {
             None => {
@@ -275,7 +296,11 @@ impl Library {
             Some(path) => {
                 let orig_img = load_image(&path, dimensions.0, dimensions.1)?;
                 //.map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
-                let img = resize(&orig_img, dimensions, filter);
+                let img = if fill {
+                    resize_to_fill(&orig_img, dimensions, filter)
+                } else {
+                    resize(&orig_img, dimensions, filter)
+                };
                 let buf = save_to_jpeg_bytes(&img)
                     .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
                 Ok(buf)
@@ -286,6 +311,7 @@ impl Library {
         &self,
         media_items_id: &str,
         dimensions: (Option<u32>, Option<u32>),
+        fill: bool,
     ) -> Option<Vec<u8>> {
         fn cache_key(media_items_id: &str, dimensions: (Option<u32>, Option<u32>)) -> String {
             let dim = match dimensions {
@@ -308,6 +334,7 @@ impl Library {
                     media_items_id,
                     dimensions,
                     FilterType::Builtin(imageops::FilterType::Lanczos3),
+                    fill,
                 ) {
                     Ok(bytes) => bytes,
                     Err(e) => {
diff --git a/src/web.rs b/src/web.rs
index d5b1302..ffb600e 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -73,6 +73,7 @@ fn album(lib: Library, id: String) -> Result<impl warp::Reply, warp::Rejection>
 struct ImageParams {
     w: Option<u32>,
     h: Option<u32>,
+    fill: Option<bool>,
 }
 
 fn image(
@@ -81,7 +82,11 @@ fn image(
     params: ImageParams,
 ) -> Result<impl warp::Reply, warp::Rejection> {
     // TODO(wathiede): add caching headers.
-    match lib.thumbnail(&media_items_id, (params.w, params.h)) {
+    match lib.thumbnail(
+        &media_items_id,
+        (params.w, params.h),
+        params.fill.unwrap_or(false),
+    ) {
         None => {
             warn!("Couldn't find original {}", &media_items_id);
             Err(warp::reject::not_found())