LibGfx/JPEGXL: Add support for x4 and x8 upsampling

All the logic is exactly the same as for x2 upsampling, so this commit
essentially boils down to adding arrays for default weights and the
logic to select the correct array.

Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp

@@ -250,11 +250,49 @@ static ErrorOr<Extensions> read_extensions(LittleEndianInputBitStream& stream)
 ///
 
 /// K.2 - Non-separable upsampling
-Array<double, 15> s_d_up2 {
+Array s_d_up2 {
     -0.01716200, -0.03452303, -0.04022174, -0.02921014, -0.00624645,
     0.14111091, 0.28896755, 0.00278718, -0.01610267, 0.56661550,
     0.03777607, -0.01986694, -0.03144731, -0.01185068, -0.00213539
 };
+
+Array s_d_up4 = {
+    -0.02419067, -0.03491987, -0.03693351, -0.03094285, -0.00529785,
+    -0.01663432, -0.03556863, -0.03888905, -0.03516850, -0.00989469,
+    0.23651958, 0.33392945, -0.01073543, -0.01313181, -0.03556694,
+    0.13048175, 0.40103025, 0.03951150, -0.02077584, 0.46914198,
+    -0.00209270, -0.01484589, -0.04064806, 0.18942530, 0.56279892,
+    0.06674400, -0.02335494, -0.03551682, -0.00754830, -0.02267919,
+    -0.02363578, 0.00315804, -0.03399098, -0.01359519, -0.00091653,
+    -0.00335467, -0.01163294, -0.01610294, -0.00974088, -0.00191622,
+    -0.01095446, -0.03198464, -0.04455121, -0.02799790, -0.00645912,
+    0.06390599, 0.22963888, 0.00630981, -0.01897349, 0.67537268,
+    0.08483369, -0.02534994, -0.02205197, -0.01667999, -0.00384443
+};
+
+Array s_d_up8 {
+    -0.02928613, -0.03706353, -0.03783812, -0.03324558, -0.00447632, -0.02519406, -0.03752601, -0.03901508, -0.03663285, -0.00646649,
+    -0.02066407, -0.03838633, -0.04002101, -0.03900035, -0.00901973, -0.01626393, -0.03954148, -0.04046620, -0.03979621, -0.01224485,
+    0.29895328, 0.35757708, -0.02447552, -0.01081748, -0.04314594, 0.23903219, 0.41119301, -0.00573046, -0.01450239, -0.04246845,
+    0.17567618, 0.45220643, 0.02287757, -0.01936783, -0.03583255, 0.11572472, 0.47416733, 0.06284440, -0.02685066, 0.42720050,
+    -0.02248939, -0.01155273, -0.04562755, 0.28689496, 0.49093869, -0.00007891, -0.01545926, -0.04562659, 0.21238920, 0.53980934,
+    0.03369474, -0.02070211, -0.03866988, 0.14229550, 0.56593398, 0.08045181, -0.02888298, -0.03680918, -0.00542229, -0.02920477,
+    -0.02788574, -0.02118180, -0.03942402, -0.00775547, -0.02433614, -0.03193943, -0.02030828, -0.04044014, -0.01074016, -0.01930822,
+    -0.03620399, -0.01974125, -0.03919545, -0.01456093, -0.00045072, -0.00360110, -0.01020207, -0.01231907, -0.00638988, -0.00071592,
+    -0.00279122, -0.00957115, -0.01288327, -0.00730937, -0.00107783, -0.00210156, -0.00890705, -0.01317668, -0.00813895, -0.00153491,
+    -0.02128481, -0.04173044, -0.04831487, -0.03293190, -0.00525260, -0.01720322, -0.04052736, -0.05045706, -0.03607317, -0.00738030,
+    -0.01341764, -0.03965629, -0.05151616, -0.03814886, -0.01005819, 0.18968273, 0.33063684, -0.01300105, -0.01372950, -0.04017465,
+    0.13727832, 0.36402234, 0.01027890, -0.01832107, -0.03365072, 0.08734506, 0.38194295, 0.04338228, -0.02525993, 0.56408126,
+    0.00458352, -0.01648227, -0.04887868, 0.24585519, 0.62026135, 0.04314807, -0.02213737, -0.04158014, 0.16637289, 0.65027023,
+    0.09621636, -0.03101388, -0.04082742, -0.00904519, -0.02790922, -0.02117818, 0.00798662, -0.03995711, -0.01243427, -0.02231705,
+    -0.02946266, 0.00992055, -0.03600283, -0.01684920, -0.00111684, -0.00411204, -0.01297130, -0.01723725, -0.01022545, -0.00165306,
+    -0.00313110, -0.01218016, -0.01763266, -0.01125620, -0.00231663, -0.01374149, -0.03797620, -0.05142937, -0.03117307, -0.00581914,
+    -0.01064003, -0.03608089, -0.05272168, -0.03375670, -0.00795586, 0.09628104, 0.27129991, -0.00353779, -0.01734151, -0.03153981,
+    0.05686230, 0.28500998, 0.02230594, -0.02374955, 0.68214326, 0.05018048, -0.02320852, -0.04383616, 0.18459474, 0.71517975,
+    0.10805613, -0.03263677, -0.03637639, -0.01394373, -0.02511203, -0.01728636, 0.05407331, -0.02867568, -0.01893131, -0.00240854,
+    -0.00446511, -0.01636187, -0.02377053, -0.01522848, -0.00333334, -0.00819975, -0.02964169, -0.04499287, -0.02745350, -0.00612408,
+    0.02727416, 0.19446600, 0.00159832, -0.02232473, 0.74982506, 0.11452620, -0.03348048, -0.01605681, -0.02070339, -0.00458223
+};
 ///
 
 /// D.3 - Image metadata
@@ -307,7 +345,8 @@ struct ImageMetadata {
     u8 cw_mask { 0 };
 
     Array<double, 15> up2_weight = s_d_up2;
-    // TODO: add up[4, 8]_weight
+    Array<double, 55> up4_weight = s_d_up4;
+    Array<double, 210> up8_weight = s_d_up8;
 };
 
 static ErrorOr<ImageMetadata> read_metadata_header(LittleEndianInputBitStream& stream)
@@ -1529,11 +1568,19 @@ static ErrorOr<void> apply_upsampling(Image& image, ImageMetadata const& metadat
     }
 
     if (frame.frame_header.upsampling > 1 || ec_max.value_or(0) > 1) {
-        if (frame.frame_header.upsampling > 2 || ec_max.value_or(0) > 2)
+        if (ec_max.value_or(0) > 2)
             TODO();
 
         auto const k = frame.frame_header.upsampling;
 
+        auto weight = [k, &metadata](u8 index) -> double {
+            if (k == 2)
+                return metadata.up2_weight[index];
+            if (k == 4)
+                return metadata.up4_weight[index];
+            return metadata.up8_weight[index];
+        };
+
         // FIXME: Use ec_upsampling for extra-channels
         for (auto& channel : image.channels()) {
             auto upsampled = TRY(Channel::create(k * channel.width(), k * channel.height()));
@@ -1565,7 +1612,7 @@ static ErrorOr<void> apply_upsampling(Image& image, ImageMetadata const& metadat
                                     W_min = min(W_min, origin_sample);
                                     W_max = max(W_max, origin_sample);
 
-                                    sum += origin_sample * metadata.up2_weight[index];
+                                    sum += origin_sample * weight(index);
                                 }
                             }