diff --git a/lib/dicom.go b/lib/dicom.go
index 7640c3e..700f997 100644
--- a/lib/dicom.go
+++ b/lib/dicom.go
@@ -832,10 +832,21 @@ func getTransferSyntax(data []byte) string {
 }
 
 func isCompressedTransferSyntax(ts string) bool {
-	return strings.HasPrefix(ts, "1.2.840.10008.1.2.4")
+	// JPEG family:        1.2.840.10008.1.2.4.x  (baseline, extended, lossless, JPEG 2000, etc.)
+	// JPEG-LS:            1.2.840.10008.1.2.4.80 / .81
+	// JPEG 2000 Lossless: 1.2.840.10008.1.2.4.90
+	// JPEG 2000 Lossy:    1.2.840.10008.1.2.4.91
+	// JPEG 2000 Multi:    1.2.840.10008.1.2.4.92 / .93
+	// RLE Lossless:       1.2.840.10008.1.2.5
+	// Deflated:           1.2.840.10008.1.2.1.99
+	return strings.HasPrefix(ts, "1.2.840.10008.1.2.4") ||
+		ts == "1.2.840.10008.1.2.5" ||
+		ts == "1.2.840.10008.1.2.1.99"
 }
 
-// decompressDICOM uses gdcmconv to decompress any JPEG-compressed DICOM.
+// decompressDICOM uses gdcmconv to decompress any compressed DICOM transfer
+// syntax (JPEG, JPEG 2000 Lossless/Lossy, JPEG-LS, RLE, Deflated).
+// Requires gdcmconv from libgdcm-tools (apt install libgdcm-tools).
 func decompressDICOM(dicomPath string) ([]byte, error) {
 	tmpFile := fmt.Sprintf("/tmp/dcm_%d_%d.dcm", os.Getpid(), time.Now().UnixNano())
 	defer os.Remove(tmpFile)