diff --git a/kernel/model/ocr.go b/kernel/model/ocr.go
index e45318261..ef18d8f34 100644
--- a/kernel/model/ocr.go
+++ b/kernel/model/ocr.go
@@ -34,8 +34,8 @@ func autoOCRAssets() {
 	assets := getUnOCRAssetsAbsPaths()
 	if 0 < len(assets) {
 		poolSize := runtime.NumCPU()
-		if 4 < poolSize {
-			poolSize = 4
+		if 2 < poolSize {
+			poolSize = 2
 		}
 		waitGroup := &sync.WaitGroup{}
 		p, _ := ants.NewPoolWithFunc(poolSize, func(arg interface{}) {
diff --git a/kernel/util/tesseract.go b/kernel/util/tesseract.go
index 7fd132b88..94decdff7 100644
--- a/kernel/util/tesseract.go
+++ b/kernel/util/tesseract.go
@@ -69,6 +69,8 @@ func Tesseract(imgAbsPath string) string {
 		return ""
 	}
 
+	defer logging.Recover()
+
 	if !IsTesseractExtractable(imgAbsPath) {
 		return ""
 	}