Add experimental support for JPEG-XL, requires libvips with libjxl

The prebuilt binaries do not include support for this format.

src/common.cc

@@ -207,6 +207,9 @@ namespace sharp {
   bool IsAvif(std::string const &str) {
     return EndsWith(str, ".avif") || EndsWith(str, ".AVIF");
   }
+  bool IsJxl(std::string const &str) {
+    return EndsWith(str, ".jxl") || EndsWith(str, ".JXL");
+  }
   bool IsDz(std::string const &str) {
     return EndsWith(str, ".dzi") || EndsWith(str, ".DZI");
   }
@@ -237,6 +240,7 @@ namespace sharp {
       case ImageType::PPM: id = "ppm"; break;
       case ImageType::FITS: id = "fits"; break;
       case ImageType::EXR: id = "exr"; break;
+      case ImageType::JXL: id = "jxl"; break;
       case ImageType::VIPS: id = "vips"; break;
       case ImageType::RAW: id = "raw"; break;
       case ImageType::UNKNOWN: id = "unknown"; break;
@@ -281,6 +285,8 @@ namespace sharp {
     { "VipsForeignLoadPpmFile", ImageType::PPM },
     { "VipsForeignLoadFitsFile", ImageType::FITS },
     { "VipsForeignLoadOpenexr", ImageType::EXR },
+    { "VipsForeignLoadJxlFile", ImageType::JXL },
+    { "VipsForeignLoadJxlBuffer", ImageType::JXL },
     { "VipsForeignLoadVips", ImageType::VIPS },
     { "VipsForeignLoadVipsFile", ImageType::VIPS },
     { "VipsForeignLoadRaw", ImageType::RAW }

src/common.h

@@ -152,6 +152,7 @@ namespace sharp {
     PPM,
     FITS,
     EXR,
+    JXL,
     VIPS,
     RAW,
     UNKNOWN,
@@ -182,6 +183,7 @@ namespace sharp {
   bool IsHeic(std::string const &str);
   bool IsHeif(std::string const &str);
   bool IsAvif(std::string const &str);
+  bool IsJxl(std::string const &str);
   bool IsDz(std::string const &str);
   bool IsDzZip(std::string const &str);
   bool IsV(std::string const &str);

src/pipeline.cc

@@ -939,6 +939,21 @@ class PipelineWorker : public Napi::AsyncWorker {
           area->free_fn = nullptr;
           vips_area_unref(area);
           baton->formatOut = "dz";
+        } else if (baton->formatOut == "jxl" ||
+          (baton->formatOut == "input" && inputImageType == sharp::ImageType::JXL)) {
+          // Write JXL to buffer
+          image = sharp::RemoveAnimationProperties(image);
+          VipsArea *area = reinterpret_cast<VipsArea*>(image.jxlsave_buffer(VImage::option()
+            ->set("strip", !baton->withMetadata)
+            ->set("distance", baton->jxlDistance)
+            ->set("tier", baton->jxlDecodingTier)
+            ->set("effort", baton->jxlEffort)
+            ->set("lossless", baton->jxlLossless)));
+          baton->bufferOut = static_cast<char*>(area->data);
+          baton->bufferOutLength = area->length;
+          area->free_fn = nullptr;
+          vips_area_unref(area);
+          baton->formatOut = "jxl";
         } else if (baton->formatOut == "raw" ||
           (baton->formatOut == "input" && inputImageType == sharp::ImageType::RAW)) {
           // Write raw, uncompressed image data to buffer
@@ -977,6 +992,7 @@ class PipelineWorker : public Napi::AsyncWorker {
         bool const isTiff = sharp::IsTiff(baton->fileOut);
         bool const isJp2 = sharp::IsJp2(baton->fileOut);
         bool const isHeif = sharp::IsHeif(baton->fileOut);
+        bool const isJxl = sharp::IsJxl(baton->fileOut);
         bool const isDz = sharp::IsDz(baton->fileOut);
         bool const isDzZip = sharp::IsDzZip(baton->fileOut);
         bool const isV = sharp::IsV(baton->fileOut);
@@ -1094,6 +1110,17 @@ class PipelineWorker : public Napi::AsyncWorker {
               ? VIPS_FOREIGN_SUBSAMPLE_OFF : VIPS_FOREIGN_SUBSAMPLE_ON)
             ->set("lossless", baton->heifLossless));
           baton->formatOut = "heif";
+        } else if (baton->formatOut == "jxl" || (mightMatchInput && isJxl) ||
+          (willMatchInput && inputImageType == sharp::ImageType::JXL)) {
+          // Write JXL to file
+          image = sharp::RemoveAnimationProperties(image);
+          image.jxlsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
+            ->set("strip", !baton->withMetadata)
+            ->set("distance", baton->jxlDistance)
+            ->set("tier", baton->jxlDecodingTier)
+            ->set("effort", baton->jxlEffort)
+            ->set("lossless", baton->jxlLossless));
+          baton->formatOut = "jxl";
         } else if (baton->formatOut == "dz" || isDz || isDzZip) {
           // Write DZ to file
           if (isDzZip) {
@@ -1579,6 +1606,10 @@ Napi::Value pipeline(const Napi::CallbackInfo& info) {
     options, "heifCompression", VIPS_TYPE_FOREIGN_HEIF_COMPRESSION);
   baton->heifEffort = sharp::AttrAsUint32(options, "heifEffort");
   baton->heifChromaSubsampling = sharp::AttrAsStr(options, "heifChromaSubsampling");
+  baton->jxlDistance = sharp::AttrAsDouble(options, "jxlDistance");
+  baton->jxlDecodingTier = sharp::AttrAsUint32(options, "jxlDecodingTier");
+  baton->jxlEffort = sharp::AttrAsUint32(options, "jxlEffort");
+  baton->jxlLossless = sharp::AttrAsBool(options, "jxlLossless");
   baton->rawDepth = sharp::AttrAsEnum<VipsBandFormat>(options, "rawDepth", VIPS_TYPE_BAND_FORMAT);
   // Animated output properties
   if (sharp::HasAttr(options, "loop")) {

src/pipeline.h

@@ -182,6 +182,10 @@ struct PipelineBaton {
   int heifEffort;
   std::string heifChromaSubsampling;
   bool heifLossless;
+  double jxlDistance;
+  int jxlDecodingTier;
+  int jxlEffort;
+  bool jxlLossless;
   VipsBandFormat rawDepth;
   std::string err;
   bool withMetadata;
@@ -335,6 +339,10 @@ struct PipelineBaton {
     heifEffort(4),
     heifChromaSubsampling("4:4:4"),
     heifLossless(false),
+    jxlDistance(1.0),
+    jxlDecodingTier(0),
+    jxlEffort(7),
+    jxlLossless(false),
     rawDepth(VIPS_FORMAT_UCHAR),
     withMetadata(false),
     withMetadataOrientation(-1),

src/utilities.cc

@@ -115,7 +115,7 @@ Napi::Value format(const Napi::CallbackInfo& info) {
   Napi::Object format = Napi::Object::New(env);
   for (std::string const f : {
     "jpeg", "png", "webp", "tiff", "magick", "openslide", "dz",
-    "ppm", "fits", "gif", "svg", "heif", "pdf", "vips", "jp2k"
+    "ppm", "fits", "gif", "svg", "heif", "pdf", "vips", "jp2k", "jxl"
   }) {
     // Input
     const VipsObjectClass *oc = vips_class_find("VipsOperation", (f + "load").c_str());