feat: allow per-format quality settings

src/runtime/image.ts

@@ -91,6 +91,24 @@ function resolveImage(ctx: ImageCTX, input: string, options: ImageOptions): Reso
   }
 
   const _options = defu(options, preset, defaults as Partial<ImageOptions>)
+
+  // Determine the final format (might come from modifiers, defaults, or global config)
+  const finalFormat = (_options.modifiers?.format as string | undefined) || ctx.options.format?.[0]
+
+  if (!_options.modifiers?.quality && typeof ctx.options.quality === 'object') {
+    const qualityMap = ctx.options.quality as Record<string, number>
+    const mappedQuality = (finalFormat && qualityMap[finalFormat]) ?? qualityMap.default ?? Object.values(qualityMap)[0]
+    if (typeof mappedQuality === 'number') {
+      _options.modifiers = { ..._options.modifiers, quality: mappedQuality }
+    }
+  }
+
+  // Resolve quality: if it's an object (quality map), resolve to number based on format
+  if (_options.modifiers?.quality && typeof _options.modifiers.quality === 'object') {
+    const qualityMap = _options.modifiers.quality as Record<string, number>
+    _options.modifiers.quality = (finalFormat && qualityMap[finalFormat]) || qualityMap.default
+  }
+
   const resolvedOptions = {
     ..._options,
     modifiers: {

src/runtime/utils/props.ts

@@ -54,7 +54,7 @@ export const useImageProps = <Provider extends keyof ConfiguredImageProviders>(p
       width: props.width,
       height: props.height,
       format: props.format,
-      quality: props.quality || $img.options.quality,
+      quality: props.quality ?? (typeof $img.options.quality === 'object' ? undefined : $img.options.quality),
       background: props.background,
       fit: props.fit,
     } satisfies Partial<ImageModifiers>

src/types/image.ts

@@ -24,7 +24,9 @@ export interface ImageOptions<Provider extends keyof ConfiguredImageProviders =
   preset?: string
   densities?: string
   modifiers?: Partial<Omit<ImageModifiers, 'format' | 'quality' | 'background' | 'fit'>>
-    & ('modifiers' extends keyof ConfiguredImageProviders[Provider] ? ConfiguredImageProviders[Provider]['modifiers'] : Record<string, unknown>)
+    & ('modifiers' extends keyof ConfiguredImageProviders[Provider]
+      ? ConfiguredImageProviders[Provider]['modifiers']
+      : Record<string, unknown>)
   sizes?: string | Record<string, any>
 }
 
@@ -61,7 +63,7 @@ export interface CreateImageOptions {
   domains: string[]
   densities: number[]
   format: string[]
-  quality?: number
+  quality?: number | Record<string, number>
   runtimeConfig: RuntimeConfig
 }
 

test/unit/bundle.test.ts

@@ -22,7 +22,7 @@ describe.skipIf(process.env.ECOSYSTEM_CI || isWindows)('nuxt image bundle size',
       }),
     ])
 
-    expect(roundToKilobytes(withImage.totalBytes - withoutImage.totalBytes)).toMatchInlineSnapshot(`"12.8k"`)
+    expect(roundToKilobytes(withImage.totalBytes - withoutImage.totalBytes)).toMatchInlineSnapshot(`"13.2k"`)
   })
 })