diff --git a/go.mod b/go.mod
index 7032ca8..cf2c23a 100644
--- a/go.mod
+++ b/go.mod
@@ -11,7 +11,7 @@ require (
 	github.com/xiaoqidun/guigo v0.0.0-20261017142315-0279420b6e12
 	github.com/xiaoqidun/j2kgo v1.0.2
 	github.com/xiaoqidun/jbig2 v1.1.8
-	github.com/xiaoqidun/pdfgo v0.0.0-20261016003351-18348c283ac1
+	github.com/xiaoqidun/pdfgo v0.0.0-20261017161421-0b88b77eefc9
 	golang.org/x/crypto v0.58.0
 	golang.org/x/image v0.47.0
 	golang.org/x/text v0.43.0
diff --git a/go.sum b/go.sum
index 111bdae..ecade45 100644
--- a/go.sum
+++ b/go.sum
@@ -64,8 +64,8 @@ github.com/xiaoqidun/j2kgo v1.0.2 h1:OAjjEOfaBaQzBNcj9wx+eM68UI5pewR6SzNZa1R1DIw
 github.com/xiaoqidun/j2kgo v1.0.2/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
 github.com/xiaoqidun/jbig2 v1.1.8 h1:dERPW7F8gs18a/DOD9gXHR3fP1Vl6KhCNsLnq5l3BIo=
 github.com/xiaoqidun/jbig2 v1.1.8/go.mod h1:9jromqVwMqlptUDEt6Yip8vqYA5I1YjhG7FgMl/Z2dA=
-github.com/xiaoqidun/pdfgo v0.0.0-20261016003351-18348c283ac1 h1:PNucIHG+qid5/GCN3wUGEqfsyrykhoazBbtPaGysWHk=
-github.com/xiaoqidun/pdfgo v0.0.0-20261016003351-18348c283ac1/go.mod h1:AaabzsObZ8Z76AcaWbo6swRROrJsblyIGB7HbieeJA4=
+github.com/xiaoqidun/pdfgo v0.0.0-20261017161421-0b88b77eefc9 h1:DsWSdFwsDpI8k0jadqcnGbpJuOpT+tIVIX5JfDFS2GQ=
+github.com/xiaoqidun/pdfgo v0.0.0-20261017161421-0b88b77eefc9/go.mod h1:AaabzsObZ8Z76AcaWbo6swRROrJsblyIGB7HbieeJA4=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
 github.com/yuin/goldmark v1.8.5 h1:r6N5afV5qj/5S4UTch8agZHJ8UxNCMwX7WjkkJam2NA=
diff --git a/internal/webui/webui.go b/internal/webui/webui.go
index 6ae1eea..dfb8c2c 100644
--- a/internal/webui/webui.go
+++ b/internal/webui/webui.go
@@ -31,6 +31,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/xiaoqidun/ofdgo"
@@ -406,6 +407,7 @@ type annotationOptions struct {
 // outputContext 定期让出浏览器线程，将取消请求传入库层长操作
 type outputContext struct {
 	context.Context
+	mu         sync.Mutex
 	cancel     context.CancelFunc
 	checkpoint func() error
 	checked    time.Time
@@ -7250,6 +7252,8 @@ func (c *outputContext) Err() error {
 	if err := c.Context.Err(); err != nil {
 		return err
 	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
 	if c.pending != 0 {
 		c.pending--
 		return nil
diff --git a/internal/webui/webui_native.go b/internal/webui/webui_native.go
index cb35356..38c45da 100644
--- a/internal/webui/webui_native.go
+++ b/internal/webui/webui_native.go
@@ -19,10 +19,12 @@ package webui
 import (
 	"bytes"
 	"context"
+	"encoding"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"reflect"
 	"strings"
 	"sync"
@@ -39,6 +41,9 @@ const (
 	platformTypeFunction
 )
 
+// nativeFields 缓存可直接展开的JSON字段，空值使用标准编码
+var nativeFields sync.Map
+
 // NativeResolver 将授权标识解析为随机读取源，生命周期由宿主管理
 // 入参: token 资源授权标识
 // 返回: io.ReaderAt 随机读取器, int64 资源大小, error 解析错误
@@ -111,6 +116,13 @@ type platformValue struct{ value any }
 // nativeCallback 同步宿主回调
 type nativeCallback func(...any) (any, error)
 
+// nativeField 保存字段名称、位置及空值省略规则
+type nativeField struct {
+	name      string
+	index     int
+	omitEmpty bool
+}
+
 // NewNativeEngine 创建独立业务会话，resolver不接收未经授权的文件路径
 func NewNativeEngine(resolve NativeResolver) *NativeEngine { return &NativeEngine{Resolve: resolve} }
 
@@ -322,6 +334,26 @@ func nativePlain(value any) any {
 		return nativePlain(v.Elem().Interface())
 	}
 	if v.Kind() == reflect.Struct {
+		if fields := nativeStructFields(v.Type()); fields != nil {
+			result := make(map[string]any, len(fields))
+			for _, field := range fields {
+				item := v.Field(field.index)
+				if field.omitEmpty {
+					switch item.Kind() {
+					case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+						if item.Len() == 0 {
+							continue
+						}
+					default:
+						if item.Kind() != reflect.Struct && item.IsZero() {
+							continue
+						}
+					}
+				}
+				result[field.name] = nativePlain(item.Interface())
+			}
+			return result
+		}
 		data, err := json.Marshal(value)
 		if err != nil {
 			panic(err)
@@ -360,9 +392,84 @@ func nativePlain(value any) any {
 		}
 		return result
 	}
+	if v.Kind() == reflect.Float32 || v.Kind() == reflect.Float64 {
+		if number := v.Float(); math.IsNaN(number) || math.IsInf(number, 0) {
+			_, err := json.Marshal(value)
+			panic(err)
+		}
+	}
 	return value
 }
 
+// nativeStructFields 按类型复用普通结构体字段，自定义编码和嵌入字段交给JSON处理
+// 入参: value 结构体类型
+// 返回: []nativeField 字段列表，nil表示使用标准编码
+func nativeStructFields(value reflect.Type) []nativeField {
+	if fields, ok := nativeFields.Load(value); ok {
+		return fields.([]nativeField)
+	}
+	var fields []nativeField
+	if nativePlainType(value, make(map[reflect.Type]bool)) {
+		fields = make([]nativeField, 0, value.NumField())
+		for i := 0; i < value.NumField(); i++ {
+			field := value.Field(i)
+			if !field.IsExported() || field.Tag.Get("json") == "-" {
+				continue
+			}
+			name, options, _ := strings.Cut(field.Tag.Get("json"), ",")
+			if name == "" {
+				name = field.Name
+			}
+			fields = append(fields, nativeField{name: name, index: i, omitEmpty: options == "omitempty"})
+		}
+	}
+	stored, _ := nativeFields.LoadOrStore(value, fields)
+	return stored.([]nativeField)
+}
+
+// nativePlainType 检查类型是否可直接展开，递归引用及复杂字段沿用标准编码
+// 入参: value 字段类型, visiting 当前类型路径
+// 返回: bool 是否可直接展开
+func nativePlainType(value reflect.Type, visiting map[reflect.Type]bool) bool {
+	if visiting[value] || value.Implements(reflect.TypeFor[json.Marshaler]()) || value.Implements(reflect.TypeFor[encoding.TextMarshaler]()) || reflect.PointerTo(value).Implements(reflect.TypeFor[json.Marshaler]()) || reflect.PointerTo(value).Implements(reflect.TypeFor[encoding.TextMarshaler]()) || value == reflect.TypeFor[json.Number]() {
+		return false
+	}
+	visiting[value] = true
+	defer delete(visiting, value)
+	switch value.Kind() {
+	case reflect.Bool, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64, reflect.String:
+		return true
+	case reflect.Pointer, reflect.Slice, reflect.Array:
+		return nativePlainType(value.Elem(), visiting)
+	case reflect.Struct:
+		names := make(map[string]bool)
+		for i := 0; i < value.NumField(); i++ {
+			field := value.Field(i)
+			if field.Anonymous {
+				return false
+			}
+			if !field.IsExported() || field.Tag.Get("json") == "-" {
+				continue
+			}
+			name, options, _ := strings.Cut(field.Tag.Get("json"), ",")
+			if name == "" {
+				name = field.Name
+			}
+			if name == "-" || names[name] || options != "" && options != "omitempty" || !nativePlainType(field.Type, visiting) {
+				return false
+			}
+			for _, char := range name {
+				if char != '_' && char != '-' && (char < 'a' || char > 'z') && (char < 'A' || char > 'Z') && (char < '0' || char > '9') {
+					return false
+				}
+			}
+			names[name] = true
+		}
+		return true
+	}
+	return false
+}
+
 // nativeFailure 转换结构化业务错误
 func nativeFailure(err error) map[string]any {
 	result := nativePlain(failureResult(err)).(map[string]any)
@@ -693,7 +800,8 @@ func (c *nativeCall) finish(name string, result map[string]any) error {
 		}
 		c.output = nil
 	} else {
-		data["blob"] = append([]byte(nil), c.buffer.Bytes()...)
+		data["blob"] = c.buffer.Bytes()
+		c.buffer = bytes.Buffer{}
 	}
 	data["size"] = c.size
 	c.committed = true
diff --git a/ofdgo_compression_parallel.go b/ofdgo_compression_parallel.go
index 4a1fef2..15abda3 100644
--- a/ofdgo_compression_parallel.go
+++ b/ofdgo_compression_parallel.go
@@ -21,23 +21,25 @@ import (
 	"image"
 	"io"
 	"runtime"
+	"strconv"
 	"sync"
 
 	baseimage "github.com/xiaoqidun/ofdgo/internal/base/image"
 )
 
-// outputImageBatchLimit 限制并行批次持有的原始编码，超限图片单独处理
+// outputImageBatchLimit 限制并行任务持有的原始编码，超限图片单独处理
 const outputImageBatchLimit = 16 << 20
 
-// outputImageWorkingSetLimit 限制并行批次的像素工作量估算，超限图片单独处理
-const outputImageWorkingSetLimit = 64 << 20
+// outputImageWorkingSetLimit 限制64位并行任务的像素工作量总估算，32位使用64MiB，超限图片单独处理
+const outputImageWorkingSetLimit = 256 << 20
 
 // outputImageJob 保存独立图片任务，不访问编辑文档或调用进度回调
 type outputImageJob struct {
-	key       outputImageKey
-	data      []byte
-	candidate []byte
-	err       error
+	key        outputImageKey
+	data       []byte
+	workingSet int
+	candidate  []byte
+	err        error
 }
 
 // outputImageSource 保存已读取资源的摘要和格式，不保留原始编码
@@ -46,6 +48,21 @@ type outputImageSource struct {
 	format string
 }
 
+// outputImageContext 保留调用方取消检查并支持提前结束并行任务
+type outputImageContext struct {
+	context.Context
+	parent context.Context
+}
+
+// Err 检查调用方及本次任务的取消状态
+// 返回: error 取消错误
+func (c outputImageContext) Err() error {
+	if err := c.Context.Err(); err != nil {
+		return err
+	}
+	return c.parent.Err()
+}
+
 // outputImageOptions 统一资源压缩及像素需求，受保护图片只进行无损编码
 // 入参: key 资源路径
 // 返回: CompressionOptions 实际策略, image.Point 像素需求
@@ -62,28 +79,52 @@ func (e *Editor) outputImageOptions(key string) (CompressionOptions, image.Point
 	return options, demand
 }
 
-// prepareOutputImages 有界并行优化独立图片，读取、缓存及进度仍在调用线程处理
+// prepareOutputImages 有界并行优化独立图片，完成后补入任务，读取、缓存及进度保持串行
 // 入参: keys 资源路径, load 串行读取方法，空值表示跳过, results 候选缓存, sources 原始资源摘要，可为空
 // 返回: error 读取、进度或取消错误
 func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, error), results map[outputImageKey][]byte, sources map[string]outputImageSource) error {
-	workers := min(2, runtime.GOMAXPROCS(0))
+	workers := min(4, runtime.GOMAXPROCS(0))
 	if workers < 2 || len(keys) < 2 {
 		return nil
 	}
-	batch := make([]outputImageJob, 0, workers)
-	size, workingSet := 0, 0
-	run := func() error {
-		if err := e.runOutputImages(batch, results); err != nil {
+	limit := outputImageWorkingSetLimit
+	if strconv.IntSize == 32 {
+		limit = 64 << 20
+	}
+	base, cancel := context.WithCancel(e.output.ctx)
+	ctx := outputImageContext{Context: base, parent: e.output.ctx}
+	var group sync.WaitGroup
+	defer func() {
+		cancel()
+		group.Wait()
+	}()
+	completed := make(chan outputImageJob, workers)
+	pending := make(map[outputImageKey]bool)
+	running, size, workingSet := 0, 0, 0
+	finish := func() error {
+		job := <-completed
+		running--
+		size -= len(job.data)
+		workingSet -= job.workingSet
+		delete(pending, job.key)
+		if err := e.output.ctx.Err(); err != nil {
 			return err
 		}
-		clear(batch)
-		batch, size, workingSet = batch[:0], 0, 0
+		results[job.key] = nil
+		if job.err == nil && len(job.candidate) < len(job.data) {
+			results[job.key] = job.candidate
+		}
 		return nil
 	}
 	for _, key := range keys {
 		if err := e.output.ctx.Err(); err != nil {
 			return err
 		}
+		for len(completed) != 0 || running == workers {
+			if err := finish(); err != nil {
+				return err
+			}
+		}
 		if err := editorProgress(e.OnWriteProgress).withContext(e.output.ctx).report("compress", e.output.completed, 0); err != nil {
 			return err
 		}
@@ -105,35 +146,43 @@ func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, e
 		if _, cached := results[cacheKey]; cached {
 			continue
 		}
-		duplicate := false
-		for _, job := range batch {
-			duplicate = duplicate || job.key == cacheKey
-		}
-		if duplicate {
+		if pending[cacheKey] {
 			continue
 		}
 		cost := outputImageWorkingSet(e.output.ctx, data)
-		if len(batch) != 0 && (len(data) > outputImageBatchLimit-size || cost > outputImageWorkingSetLimit-workingSet) {
-			if err := run(); err != nil {
+		for running != 0 && (len(data) > outputImageBatchLimit-size || cost > limit-workingSet) {
+			if err := finish(); err != nil {
 				return err
 			}
 		}
-		batch = append(batch, outputImageJob{key: cacheKey, data: data})
+		job := outputImageJob{key: cacheKey, data: data, workingSet: cost}
+		if len(data) >= outputImageBatchLimit || cost >= limit {
+			if err := e.runOutputImages([]outputImageJob{job}, results); err != nil {
+				return err
+			}
+			continue
+		}
+		pending[cacheKey] = true
+		running++
 		size += len(data)
 		workingSet += cost
-		if len(batch) == workers || size >= outputImageBatchLimit || workingSet >= outputImageWorkingSetLimit {
-			if err := run(); err != nil {
-				return err
-			}
+		group.Go(func() {
+			job.candidate, job.err = optimizeImageResource(ctx, job.data, job.key.options, job.key.size)
+			completed <- job
+		})
+	}
+	for running != 0 {
+		if err := finish(); err != nil {
+			return err
 		}
 	}
-	return run()
+	return e.output.ctx.Err()
 }
 
 // outputImageWorkingSet 按原图尺寸估算解码和重采样缓冲，不以降采样目标代替原图
 // 通常预留两份16位RGBA缓冲，TIFF另计分量、瓦片及蒙版存储；格式或尺寸不明时单独处理
 // 入参: ctx 取消上下文, data 原始图像编码
-// 返回: int 编码及像素缓冲的估算字节数，上限为单批预算
+// 返回: int 编码及像素缓冲的估算字节数，上限为outputImageWorkingSetLimit
 func outputImageWorkingSet(ctx context.Context, data []byte) int {
 	if len(data) >= outputImageWorkingSetLimit {
 		return outputImageWorkingSetLimit