From 7f186e1f80cd9db35fe821de0c5a8c7a739874e4 Mon Sep 17 00:00:00 2001 From: clawbot <35+clawbot@noreply.example.org> Date: Thu, 8 Oct 2026 04:38:18 +0000 Subject: [PATCH] Serve and accept JPEG XL as an image format (part of #222) A JPEG XL source is accepted, and orig of one is JPEG XL. The format jxl works in plain and encrypted URLs and on the generator page, served as image/jxl; auto chooses it first when Accept names image/jxl. govips sends libvips a JPEG XL distance, which overrides the quality, so q becomes a distance, keeping 100 lossy. Metadata is removed from the image before the JPEG XL save, as govips cannot have libvips strip it, and the image is given 72 dpi so that the EXIF block libvips 8.16 adds holds nothing from the source. The sRGB conversion moved ahead of the format switch, and a CMYK image with no ICC profile is converted to sRGB, as libvips cannot save CMYK as JPEG XL. Model: opus-5-5 --- README.md | 34 ++- TODO.md | 17 ++ internal/handlers/format_auto.go | 18 +- internal/handlers/jpegxl_internal_test.go | 73 ++++++ internal/httpfetcher/httpfetcher.go | 2 + internal/httpfetcher/jpegxl_internal_test.go | 20 ++ internal/httpfetcher/mock.go | 2 + internal/imageprocessor/imageprocessor.go | 109 +++++++- .../jpegxl_output_internal_test.go | 244 ++++++++++++++++++ internal/imageprocessor/testdata/cmyk.jpg | Bin 0 -> 352 bytes internal/imageprocessor/testdata/dpi-300.jpg | Bin 0 -> 799 bytes internal/imgcache/imgcache.go | 7 +- internal/imgcache/urlparser.go | 2 + internal/magic/jpegxl_internal_test.go | 58 +++++ internal/magic/magic.go | 20 +- internal/server/jpegxl_internal_test.go | 72 ++++++ internal/server/testdata/red.jxl | Bin 0 -> 74 bytes internal/templates/generator.html | 3 +- 18 files changed, 645 insertions(+), 36 deletions(-) create mode 100644 internal/handlers/jpegxl_internal_test.go create mode 100644 internal/httpfetcher/jpegxl_internal_test.go create mode 100644 internal/imageprocessor/jpegxl_output_internal_test.go create mode 100644 internal/imageprocessor/testdata/cmyk.jpg create mode 100644 internal/imageprocessor/testdata/dpi-300.jpg create mode 100644 internal/magic/jpegxl_internal_test.go create mode 100644 internal/server/jpegxl_internal_test.go create mode 100644 internal/server/testdata/red.jxl diff --git a/README.md b/README.md index bd024e6..dbbde09 100644 --- a/README.md +++ b/README.md @@ -245,7 +245,7 @@ A request whose query string cannot be decoded, or gives any parameter more than once, is refused with 400. - ``: one of `orig` (or `original`), `jpeg` (or `jpg`), `png`, `webp`, - `avif`, `gif`, or `auto` (below) + `avif`, `jxl` (JPEG XL), `gif`, or `auto` (below) - ``: `orig` or `x` (e.g. `800x600`) - `sig` and `exp`: the signature and its expiry, needed unless the host is allowlisted (see Signature Specification) @@ -253,23 +253,29 @@ once, is refused with 400. both optional (values under Signature Specification). Both are part of what is cached, so each value of either is a separate cached image. +The source image may be JPEG, PNG, GIF, WebP, AVIF, JPEG XL or SVG. The +upstream's `Content-Type` must name its format, and the image's first bytes must +match it. + With the format `auto`, pixa chooses the format for each request from its `Accept` header, in this order: -1. AVIF, when the header names `image/avif`; -2. WebP, when it names `image/webp`; -3. JPEG, when the first of `image/jpeg`, `image/*` and `*/*` that it names +1. JPEG XL, when the header names `image/jxl`; +2. AVIF, when it names `image/avif`; +3. WebP, when it names `image/webp`; +4. JPEG, when the first of `image/jpeg`, `image/*` and `*/*` that it names allows it, or when there is no `Accept` header or it is empty. An entry with `q=0` refuses its format; other `q` values do not change the -order. AVIF and WebP must be named, as clients that cannot show them also send -`image/*` and `*/*`. pixa never sends a format the client refused: when the -header allows none of the three, the answer is 406, and a header that does not -parse, or has a `q` that is not a number from 0 to 1, is refused with 400. The -signature, or the token of an encrypted URL, covers `auto` itself, so one URL -serves every client. Each format chosen is cached as a separate image, and every -answer that depends on `Accept` (the image, a 304, and the 400 and 406 above) -carries `Vary: Accept`, so a shared cache keeps the formats apart too. +order. JPEG XL, AVIF and WebP must be named, as clients that cannot show them +also send `image/*` and `*/*`. pixa never sends a format the client refused: +when the header allows none of the four, the answer is 406, and a header that +does not parse, or has a `q` that is not a number from 0 to 1, is refused +with 400. The signature, or the token of an encrypted URL, covers `auto` itself, +so one URL serves every client. Each format chosen is cached as a separate +image, and every answer that depends on `Accept` (the image, a 304, and the 400 +and 406 above) carries `Vary: Accept`, so a shared cache keeps the formats apart +too. An image is served with `Cache-Control: public, max-age=, immutable`. When the URL has an expiry (an `exp`, or the TTL of an encrypted URL), `max-age` @@ -350,6 +356,10 @@ turned off. - An image with an ICC profile is converted to sRGB first, since clients show an image with no profile as sRGB. Colours outside sRGB, such as the most saturated ones in a Display P3 photo, are clipped. +- The one exception is JPEG XL with libvips 8.16 and later: libvips then writes + an EXIF block of its own into the image, as govips cannot ask libvips to leave + it out. It holds the image's size and otherwise fixed values, such as an + orientation of 1 and a resolution of 72 dpi, and nothing from the source. ### Source Hosts diff --git a/TODO.md b/TODO.md index 9ab7aec..4622779 100644 --- a/TODO.md +++ b/TODO.md @@ -30,6 +30,23 @@ P2: security: per-IP rate limiting on the image routes # Completed Steps +- 2026-10-08 JPEG XL as an input and output format (part of #222): a source + whose bytes start with either JPEG XL signature, the bare codestream's `FF 0A` + or the container's, is detected as `image/jxl`, which the upstream fetch + accepts; `orig` of such a source is JPEG XL. The format `jxl` works in plain + and encrypted URLs and on the generator page, served as `image/jxl` and cached + like the other formats. `auto` chooses JPEG XL first when `Accept` names + `image/jxl`. govips sends libvips a JPEG XL distance with every save, so + libvips ignores the quality: pixa turns `q` into a distance with libvips' own + formula, keeping 100 lossy, and removes the metadata from the image before + saving, as govips cannot have libvips strip it from JPEG XL. libvips 8.16 and + later still write an EXIF block of their own into JPEG XL, from the image's + size, orientation and resolution, and fixed values; the image is upright and + is given 72 dpi before the save, so the block holds nothing from the source. + An image with an ICC profile is converted to sRGB before the JPEG XL save too, + and a CMYK image with none is converted to sRGB, as libvips cannot save CMYK + as JPEG XL. libvips' default effort, 7, is kept. JPEG XL is not yet the + default output. - 2026-10-08 pixad runs on the Alpine release it is built on (closes #229): the runtime stage of the `Dockerfile` uses `alpine:3.22`, the release of the `golang:1.25.4-alpine3.22` image that the test phase and the build stage use, diff --git a/internal/handlers/format_auto.go b/internal/handlers/format_auto.go index 485faed..bca3bde 100644 --- a/internal/handlers/format_auto.go +++ b/internal/handlers/format_auto.go @@ -14,8 +14,8 @@ import ( // Errors for an Accept header that an auto URL cannot be served for. var ( errInvalidAccept = errors.New("invalid Accept header") - errNotAcceptable = errors.New( - "not acceptable: auto serves image/avif, image/webp or image/jpeg") + errNotAcceptable = errors.New("not acceptable: auto serves " + + "image/jxl, image/avif, image/webp or image/jpeg") ) // chooseAutoFormat replaces the format auto in req with the format @@ -51,11 +51,11 @@ func (s *Handlers) chooseAutoFormat( } // formatForAccept returns the format an auto URL is served in for the Accept -// header accept: AVIF when it names image/avif, else WebP when it names -// image/webp, else JPEG when its most specific entry of image/jpeg, image/* -// and */* allows it, or when it names nothing. A q of 0 refuses a format. -// AVIF and WebP must be named, as clients that cannot show them send image/* -// and */* too. +// header accept: JPEG XL when it names image/jxl, else AVIF when it names +// image/avif, else WebP when it names image/webp, else JPEG when its most +// specific entry of image/jpeg, image/* and */* allows it, or when it names +// nothing. A q of 0 refuses a format. JPEG XL, AVIF and WebP must be named, as +// clients that cannot show them send image/* and */* too. func formatForAccept(accept string) (imgcache.ImageFormat, error) { qualities, err := parseAccept(accept) if err != nil { @@ -66,6 +66,10 @@ func formatForAccept(accept string) (imgcache.ImageFormat, error) { return imgcache.FormatJPEG, nil } + if qualities["image/jxl"] > 0 { + return imgcache.FormatJXL, nil + } + if qualities["image/avif"] > 0 { return imgcache.FormatAVIF, nil } diff --git a/internal/handlers/jpegxl_internal_test.go b/internal/handlers/jpegxl_internal_test.go new file mode 100644 index 0000000..68bbe14 --- /dev/null +++ b/internal/handlers/jpegxl_internal_test.go @@ -0,0 +1,73 @@ +package handlers + +import ( + "log/slog" + "net/http" + "testing" + + "github.com/davidbyttow/govips/v2/vips" + + "sneak.berlin/go/pixa/internal/imgcache" +) + +// jxlType is the content type of JPEG XL. +const jxlType = "image/jxl" + +// TestFormatForAccept_JPEGXL verifies that the format auto chooses JPEG XL +// when Accept names image/jxl, ahead of AVIF whatever their q, and AVIF when +// Accept refuses JPEG XL with q=0. +func TestFormatForAccept_JPEGXL(t *testing.T) { + t.Parallel() + + tests := []struct { + name string + accept string + want imgcache.ImageFormat + }{ + {"JPEG XL-capable browser", + "image/jxl,image/avif,image/webp,image/*,*/*;q=0.8", imgcache.FormatJXL}, + {"JPEG XL only", jxlType, imgcache.FormatJXL}, + {"JPEG XL with a lower q than AVIF", "image/avif,image/jxl;q=0.5", + imgcache.FormatJXL}, + {"q=0 on JPEG XL", "image/jxl;q=0,image/avif,*/*", imgcache.FormatAVIF}, + } + + for _, tt := range tests { + t.Run(tt.name, func(t *testing.T) { + t.Parallel() + + got, err := formatForAccept(tt.accept) + if got != tt.want || err != nil { + t.Errorf("formatForAccept(%q) = %q, %v, want %q", + tt.accept, got, err, tt.want) + } + }) + } +} + +// TestFormatAuto_JPEGXL requests an auto URL on each image route with an +// Accept header that names image/jxl, and checks that the answer is a JPEG XL +// image. +func TestFormatAuto_JPEGXL(t *testing.T) { + t.Parallel() + + h, srv := newSignedHostServer(t, slog.New(slog.DiscardHandler)) + signedURL, encryptedURL := autoPhotoURLs(t, h) + + for _, target := range []string{signedURL, encryptedURL} { + rec := requestImage(t, srv, http.MethodGet, target, + "image/jxl,image/avif,image/webp,*/*;q=0.8") + gotType := rec.Header().Get("Content-Type") + + if rec.Code != http.StatusOK || gotType != jxlType { + t.Errorf("%s: %d %s, want 200 %s; body %s", + target, rec.Code, gotType, jxlType, rec.Body) + + continue + } + + if got := vips.DetermineImageType(rec.Body.Bytes()); got != vips.ImageTypeJXL { + t.Errorf("%s: body is %s, want jxl", target, vips.ImageTypes[got]) + } + } +} diff --git a/internal/httpfetcher/httpfetcher.go b/internal/httpfetcher/httpfetcher.go index 5640cf0..dd37489 100644 --- a/internal/httpfetcher/httpfetcher.go +++ b/internal/httpfetcher/httpfetcher.go @@ -45,6 +45,7 @@ const ( contentTypeGIF = "image/gif" contentTypeWebP = "image/webp" contentTypeAVIF = "image/avif" + contentTypeJXL = "image/jxl" contentTypeSVG = "image/svg+xml" contentTypeOctetStream = "application/octet-stream" ) @@ -156,6 +157,7 @@ func DefaultConfig() *Config { contentTypeGIF, contentTypeWebP, contentTypeAVIF, + contentTypeJXL, contentTypeSVG, }, AllowHTTP: false, diff --git a/internal/httpfetcher/jpegxl_internal_test.go b/internal/httpfetcher/jpegxl_internal_test.go new file mode 100644 index 0000000..8be65ec --- /dev/null +++ b/internal/httpfetcher/jpegxl_internal_test.go @@ -0,0 +1,20 @@ +package httpfetcher + +import "testing" + +// TestJPEGXLContentType verifies that the fetcher accepts an upstream answer +// of type image/jxl by default, and that the mock fetcher serves a .jxl file +// as image/jxl. +func TestJPEGXLContentType(t *testing.T) { + t.Parallel() + + const jxlType = "image/jxl" + + if !New(DefaultConfig()).isAllowedContentType(jxlType) { + t.Errorf("isAllowedContentType(%q) = false, want true", jxlType) + } + + if got := detectContentTypeFromPath("images/photo.jxl"); got != jxlType { + t.Errorf("detectContentTypeFromPath(photo.jxl) = %q, want %q", got, jxlType) + } +} diff --git a/internal/httpfetcher/mock.go b/internal/httpfetcher/mock.go index 5dca6d8..2a3b11b 100644 --- a/internal/httpfetcher/mock.go +++ b/internal/httpfetcher/mock.go @@ -109,6 +109,8 @@ func detectContentTypeFromPath(path string) string { return contentTypeWebP case strings.HasSuffix(path, ".avif"): return contentTypeAVIF + case strings.HasSuffix(path, ".jxl"): + return contentTypeJXL case strings.HasSuffix(path, ".svg"): return contentTypeSVG default: diff --git a/internal/imageprocessor/imageprocessor.go b/internal/imageprocessor/imageprocessor.go index b7c2718..5cec4f8 100644 --- a/internal/imageprocessor/imageprocessor.go +++ b/internal/imageprocessor/imageprocessor.go @@ -65,6 +65,7 @@ const ( FormatPNG Format = "png" FormatWebP Format = "webp" FormatAVIF Format = "avif" + FormatJXL Format = "jxl" FormatGIF Format = "gif" ) @@ -305,6 +306,7 @@ const ( mimeGIF = "image/gif" mimeWebP = "image/webp" mimeAVIF = "image/avif" + mimeJXL = "image/jxl" ) // SupportedInputFormats returns MIME types this processor can read. @@ -315,6 +317,7 @@ func (p *ImageProcessor) SupportedInputFormats() []string { mimeGIF, mimeWebP, mimeAVIF, + mimeJXL, } } @@ -326,6 +329,7 @@ func (p *ImageProcessor) SupportedOutputFormats() []Format { FormatGIF, FormatWebP, FormatAVIF, + FormatJXL, } } @@ -342,6 +346,8 @@ func FormatToMIME(format Format) string { return mimeGIF case FormatAVIF: return mimeAVIF + case FormatJXL: + return mimeJXL case FormatOriginal: return "application/octet-stream" default: @@ -411,9 +417,11 @@ func (p *ImageProcessor) detectFormat(img *vips.ImageRef) string { return "webp" case vips.ImageTypeAVIF, vips.ImageTypeHEIF: return string(FormatAVIF) + case vips.ImageTypeJXL: + return string(FormatJXL) case vips.ImageTypeUnknown, vips.ImageTypeMagick, vips.ImageTypePDF, vips.ImageTypeSVG, vips.ImageTypeTIFF, vips.ImageTypeBMP, - vips.ImageTypeJP2K, vips.ImageTypeJXL: + vips.ImageTypeJP2K: return "unknown" default: return "unknown" @@ -485,6 +493,17 @@ func (p *ImageProcessor) encode( quality = defaultQuality } + // Stripping drops the ICC profile as well, and clients show an image + // with no profile as sRGB, so convert to sRGB first. "srgb" names + // libvips' built-in profile; govips' own sRGB path variable is set on + // first use but read without a lock, so concurrent requests race on it. + if img.HasICCProfile() { + err := img.TransformICCProfileWithFallback("srgb", "srgb") + if err != nil { + return nil, fmt.Errorf("failed to convert to sRGB: %w", err) + } + } + var params vips.ExportParams switch format { @@ -516,6 +535,9 @@ func (p *ImageProcessor) encode( Quality: quality, } + case FormatJXL: + return exportJXL(img, quality) + case FormatOriginal: return nil, fmt.Errorf("%w: %s", ErrUnsupportedOutputFormat, format) @@ -523,17 +545,6 @@ func (p *ImageProcessor) encode( return nil, fmt.Errorf("%w: %s", ErrUnsupportedOutputFormat, format) } - // Stripping drops the ICC profile as well, and clients show an image - // with no profile as sRGB, so convert to sRGB first. "srgb" names - // libvips' built-in profile; govips' own sRGB path variable is set on - // first use but read without a lock, so concurrent requests race on it. - if img.HasICCProfile() { - err := img.TransformICCProfileWithFallback("srgb", "srgb") - if err != nil { - return nil, fmt.Errorf("failed to convert to sRGB: %w", err) - } - } - // Drop EXIF, XMP, IPTC and the ICC profile. govips ignores this for // GIF, which carries none of them. params.StripMetadata = true @@ -546,6 +557,78 @@ func (p *ImageProcessor) encode( return output, nil } +// jxlResolution is the resolution every JPEG XL image is saved with, in +// pixels per millimetre as libvips counts it: 72 dpi, what libvips gives a +// JPEG that names none. +const jxlResolution = 72 / 25.4 + +// exportJXL encodes img as JPEG XL at quality, with libvips' default effort +// and without metadata. govips sends libvips a distance, the JPEG XL +// encoder's own measure of quality, along with the quality, and libvips then +// uses the distance alone, so the quality is also given as a distance. +func exportJXL(img *vips.ImageRef, quality int) ([]byte, error) { + // libvips converts a CMYK image to sRGB before it saves WebP, AVIF or + // PNG, but cannot save one as JPEG XL. encode has already converted + // any image with an ICC profile to sRGB, so this is CMYK with none. + if img.Interpretation() == vips.InterpretationCMYK { + err := img.ToColorSpace(vips.InterpretationSRGB) + if err != nil { + return nil, fmt.Errorf("failed to convert CMYK to sRGB: %w", err) + } + } + + // govips cannot make libvips strip metadata from JPEG XL, so it is + // removed from the image itself. RemoveMetadata removes EXIF, XMP and + // IPTC but keeps the ICC profile. + err := img.RemoveMetadata() + if err != nil { + return nil, err + } + + err = img.RemoveICCProfile() + if err != nil { + return nil, err + } + + // libvips 8.16 and later still write an EXIF block of their own, from + // the image's size, orientation and resolution, and fixed values. The + // image is upright, so its orientation is 1, but its resolution is still + // the source's. + toSave, err := img.CopyChangingResolution(jxlResolution, jxlResolution) + if err != nil { + return nil, err + } + + defer toSave.Close() + + params := vips.NewJxlExportParams() + params.Quality = quality + params.Distance = jxlDistance(quality) + + output, _, err := toSave.ExportJxl(params) + if err != nil { + return nil, err + } + + return output, nil +} + +// jxlDistance turns a quality from 1 to 100 into the JPEG XL encoder's +// distance, with the formula libvips and libjxl use for their own quality +// setting, except that 100 stays lossy (distance 0.1) where libjxl makes it +// lossless. +// +//nolint:mnd // the constants of that formula +func jxlDistance(quality int) float64 { + q := float64(quality) + + if quality >= 30 { + return 0.1 + (100-q)*0.09 + } + + return 53.0/3000.0*q*q - 23.0/20.0*q + 25.0 +} + // formatFromString converts a format string to Format. func (p *ImageProcessor) formatFromString(format string) Format { switch format { @@ -559,6 +642,8 @@ func (p *ImageProcessor) formatFromString(format string) Format { return FormatWebP case string(FormatAVIF): return FormatAVIF + case string(FormatJXL): + return FormatJXL default: return FormatJPEG } diff --git a/internal/imageprocessor/jpegxl_output_internal_test.go b/internal/imageprocessor/jpegxl_output_internal_test.go new file mode 100644 index 0000000..71f8f14 --- /dev/null +++ b/internal/imageprocessor/jpegxl_output_internal_test.go @@ -0,0 +1,244 @@ +package imageprocessor + +import ( + "bytes" + "io" + "math" + "os" + "testing" + + "github.com/davidbyttow/govips/v2/vips" +) + +// TestImageProcessor_EncodeJPEGXL converts a JPEG to a smaller JPEG XL and +// checks the content type, and the format and size the output loads as. +func TestImageProcessor_EncodeJPEGXL(t *testing.T) { + t.Parallel() + + req := &Request{Size: Size{Width: 100, Height: 75}, Format: FormatJXL} + + result, err := New(Params{}).Process( + t.Context(), bytes.NewReader(createTestJPEG(t, 200, 150)), req, + ) + if err != nil { + t.Fatalf("Process() error = %v", err) + } + + defer func() { _ = result.Content.Close() }() + + if result.ContentType != "image/jxl" { + t.Errorf("ContentType = %q, want image/jxl", result.ContentType) + } + + data, err := io.ReadAll(result.Content) + if err != nil { + t.Fatalf("failed to read result: %v", err) + } + + output, err := vips.NewImageFromBuffer(data) + if err != nil { + t.Fatalf("failed to load the output: %v", err) + } + + defer output.Close() + + if output.Format() != vips.ImageTypeJXL { + t.Errorf("output format = %s, want jxl", vips.ImageTypes[output.Format()]) + } + + if output.Width() != 100 || output.Height() != 75 { + t.Errorf("output size = %dx%d, want 100x75", output.Width(), output.Height()) + } +} + +// TestImageProcessor_JPEGXLQuality verifies that the quality reaches the JPEG +// XL encoder: the same image comes out smaller at quality 30 than at 90. +func TestImageProcessor_JPEGXLQuality(t *testing.T) { + t.Parallel() + + input := createTestJPEG(t, 400, 300) + outputBytes := make(map[int]int64) + + for _, quality := range []int{30, 90} { + result, err := New(Params{}).Process(t.Context(), + bytes.NewReader(input), &Request{Format: FormatJXL, Quality: quality}) + if err != nil { + t.Fatalf("Process() at quality %d error = %v", quality, err) + } + + _ = result.Content.Close() + outputBytes[quality] = result.ContentLength + } + + if outputBytes[30] >= outputBytes[90] { + t.Errorf("%d bytes at quality 30, %d at 90, want fewer at 30", + outputBytes[30], outputBytes[90]) + } +} + +// TestImageProcessor_JPEGXLDropsSourceEXIF verifies that none of the source's +// EXIF reaches a JPEG XL output. libvips 8.16 and later write an EXIF block of +// their own into JPEG XL (orientation, resolution, size, colour space and +// fixed defaults), and govips cannot ask them to leave it out, so the test +// looks for the source's fields rather than for no EXIF at all. +func TestImageProcessor_JPEGXLDropsSourceEXIF(t *testing.T) { + t.Parallel() + + input, err := os.ReadFile("testdata/gps-exif.jpg") + if err != nil { + t.Fatalf("failed to read test JPEG: %v", err) + } + + exif := processAndDecode(t, input, &Request{Format: FormatJXL}).GetExif() + + for _, field := range []string{ + "exif-ifd0-Make", "exif-ifd0-Model", "exif-ifd2-BodySerialNumber", + "exif-ifd2-DateTimeOriginal", "exif-ifd3-GPSLatitude", + "exif-ifd3-GPSLongitude", + } { + if value, found := exif[field]; found { + t.Errorf("output has %s: %s", field, value) + } + } +} + +// TestImageProcessor_JPEGXLDropsSourceResolution verifies that the source's +// resolution does not reach the EXIF block libvips 8.16 and later write into +// JPEG XL. A JPEG XL image holds its resolution in that block alone, so the +// resolution the output loads with is the block's. +func TestImageProcessor_JPEGXLDropsSourceResolution(t *testing.T) { + t.Parallel() + + // dpi-300.jpg is a flat 8x8 grey image with a resolution of 300 dpi. + input, err := os.ReadFile("testdata/dpi-300.jpg") + if err != nil { + t.Fatalf("failed to read test JPEG: %v", err) + } + + output := processAndDecode(t, input, &Request{Format: FormatJXL}) + + // libvips gives the resolution in pixels per millimetre. + xDPI := math.Round(output.ResX() * 25.4) + yDPI := math.Round(output.ResY() * 25.4) + + if xDPI == 300 || yDPI == 300 { + t.Errorf("output resolution = %vx%v dpi, the source's", xDPI, yDPI) + } +} + +// TestImageProcessor_JPEGXLAppliesEXIFOrientation verifies that a JPEG XL +// output is turned upright, as TestImageProcessor_AppliesEXIFOrientation does +// for PNG. +func TestImageProcessor_JPEGXLAppliesEXIFOrientation(t *testing.T) { + t.Parallel() + + // orientation-6.jpg is stored 16x8, red on the left and blue on the + // right, with EXIF orientation 6 (turn 90 degrees clockwise to view). + // Upright it is 8x16, red on top and blue below. + input, err := os.ReadFile("testdata/orientation-6.jpg") + if err != nil { + t.Fatalf("failed to read test JPEG: %v", err) + } + + output := processAndDecode(t, input, &Request{Format: FormatJXL}) + + if output.Width() != 8 || output.Height() != 16 { + t.Fatalf("output is %dx%d, want 8x16", output.Width(), output.Height()) + } + + top, err := output.GetPoint(4, 0) + if err != nil { + t.Fatalf("GetPoint() error = %v", err) + } + + bottom, err := output.GetPoint(4, 15) + if err != nil { + t.Fatalf("GetPoint() error = %v", err) + } + + if top[0] <= top[2] || bottom[2] <= bottom[0] { + t.Errorf("top pixel = %v, bottom pixel = %v, want red above blue", + top, bottom) + } +} + +// TestImageProcessor_JPEGXLConvertsWideGamutToSRGB verifies that a JPEG XL +// output is converted to sRGB, as TestImageProcessor_ConvertsWideGamutToSRGB +// does for PNG. It does not check for an ICC profile, as libvips reports one +// for every JPEG XL image it loads. +func TestImageProcessor_JPEGXLConvertsWideGamutToSRGB(t *testing.T) { + t.Parallel() + + // display-p3.jpg is a flat 8x8 image with the Display P3 profile + // embedded, filled with Display P3 (234, 51, 35), which is sRGB red. + input, err := os.ReadFile("testdata/display-p3.jpg") + if err != nil { + t.Fatalf("failed to read test JPEG: %v", err) + } + + output := processAndDecode(t, input, &Request{Format: FormatJXL}) + + pixel, err := output.GetPoint(4, 4) + if err != nil { + t.Fatalf("GetPoint() error = %v", err) + } + + want := []float64{255, 0, 0} + for i := range want { + if math.Abs(pixel[i]-want[i]) > 5 { + t.Fatalf("pixel = %v, want within 5 of %v", pixel, want) + } + } +} + +// TestImageProcessor_JPEGXLFromCMYK verifies that a CMYK JPEG with no ICC +// profile can be served as JPEG XL, in sRGB. +func TestImageProcessor_JPEGXLFromCMYK(t *testing.T) { + t.Parallel() + + // cmyk.jpg is a flat 8x8 CMYK image with no ICC profile, filled with + // full cyan and no magenta, yellow or black. + input, err := os.ReadFile("testdata/cmyk.jpg") + if err != nil { + t.Fatalf("failed to read test JPEG: %v", err) + } + + output := processAndDecode(t, input, &Request{Format: FormatJXL}) + + if output.Bands() != 3 { + t.Fatalf("output has %d bands, want 3", output.Bands()) + } + + pixel, err := output.GetPoint(4, 4) + if err != nil { + t.Fatalf("GetPoint() error = %v", err) + } + + // Cyan in sRGB: little red, much green and blue. + if pixel[0] > 50 || pixel[1] < 100 || pixel[2] < 200 { + t.Errorf("pixel = %v, want cyan", pixel) + } +} + +// TestJXLDistance verifies the JPEG XL distance for a few qualities: 90 is +// distance 1, the encoder's own default, and 100 stays lossy. +func TestJXLDistance(t *testing.T) { + t.Parallel() + + tests := []struct { + quality int + want float64 + }{ + {quality: 100, want: 0.1}, + {quality: 90, want: 1}, + {quality: 30, want: 6.4}, + {quality: 20, want: 9.0667}, + } + + for _, tt := range tests { + got := jxlDistance(tt.quality) + if math.Abs(got-tt.want) > 0.0001 { + t.Errorf("jxlDistance(%d) = %v, want %v", tt.quality, got, tt.want) + } + } +} diff --git a/internal/imageprocessor/testdata/cmyk.jpg b/internal/imageprocessor/testdata/cmyk.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ba18a4e94d7adfef6f12579a69f9368d7d9414df GIT binary patch literal 352 zcmex=(iUwW$pkka<)WpdpCN3c zY31zV>gMj@=@lFj8WtWA8I_!pnwFlCnN?g;T2@|BS=HRq+ScCD*)?hMl&RCE&zL!D z(c&dbmn~nha@D5ITefc7zGLUELx+zXJ$C%W$y1juU%7hi`i+~n9zJ^f~kX3=9lx3_^^|42(b)2um@tg6S|ITN=ua1F|)sYM6j* zVJ3w7%yt&AdZ2+|@L)0v!wY5x1{lr8z%YTGfdwdMU}R{(I1$2T1e(CG04i>1V8FNl zV&eb*3=B*QASQy`#*D-U8UOz_gEIp&6B7sl0SgeZa@(J>Ba|?(G2nvgcii+~^i%W=!NC=6DihvAZWCrSCVdZ3HyL4rWF{1|~s9W8LvnOK-X zt_I51f`WoYkX1<0(2-3zFp*uUP{gQl;zAB(r;P_igD!qhF-|IK;^Yz&myncFRa4i{ z)G{$OGqmaka3YSZQ|TeofBv2)j SVP*tI9. part of the image URL + contentType string + imageType vips.ImageType + width, height int + }{ + {"32x24.png", "image/png", vips.ImageTypePNG, 32, 24}, + {"32x24.jxl", "image/jxl", vips.ImageTypeJXL, 32, 24}, + {"orig.orig", "image/jxl", vips.ImageTypeJXL, 64, 48}, + } + + for _, tt := range tests { + target := "/v1/image/" + upstreamHost + "/red.jxl/" + tt.sizeFormat + + for _, wantCache := range []string{"MISS", "HIT"} { + rec := getImage(t, s, target) + gotType := rec.Header().Get("Content-Type") + gotCache := rec.Header().Get("X-Pixa-Cache") + + if gotType != tt.contentType || gotCache != wantCache { + t.Errorf("%s: %s, X-Pixa-Cache %s, want %s, %s", + target, gotType, gotCache, tt.contentType, wantCache) + } + + img, err := vips.NewImageFromBuffer(rec.Body.Bytes()) + if err != nil { + t.Fatalf("%s: loading the image: %v", target, err) + } + + if img.Format() != tt.imageType || + img.Width() != tt.width || img.Height() != tt.height { + t.Errorf("%s: %s %dx%d, want %s %dx%d", target, + vips.ImageTypes[img.Format()], img.Width(), img.Height(), + vips.ImageTypes[tt.imageType], tt.width, tt.height) + } + + img.Close() + } + } +} diff --git a/internal/server/testdata/red.jxl b/internal/server/testdata/red.jxl new file mode 100644 index 0000000000000000000000000000000000000000..9429f50184397295744c4db41e7ec530b0e96f54 GIT binary patch literal 74 zcmV-Q0JZ=B3d;ro3<2{)699k;l~KkGUe5J=`JuyN+QxN;w%WF^gt6IP7$gM1fsx0% gc<~yCQUL<o9L? -- 2.54.0