## 1 Introduction  
The use of images from multi-sensor devices such as multi-camera smartphones and 360-degree capturing cameras is increasing. Such devices are now widely available to consumers with various applications [1, 2]. A 360-degree image covers the omnidirectional scene, which is created by stitching images captured by multiple sensors or cameras and mapping them onto a 2D plane through a projection method. Several software packages are used to stitch images to 360-degree images. Today, with millions of engaged users, 360-degree images and videos have gained immense popularity. There are many benefits of 360-degree images. Users can feel like they are on-site while off-site, enabling better decision making, reducing the need for costly visits, and minimizing confusion and ambiguity. The 360-degree images are used for training [3], tourism and marketing [4], entertainment, education [5], navigation, virtual and augmented reality applications [6], etc. There are many websites where 360-degree images are provided in spherical forms. In addition, there are many viewer software packages available for use in viewing 360-degree images. Some viewers are developed by camera makers; others are developed by third-party software developers. Many web-based players are also available for use in viewing 360-degree images. Viewers of 360-degree images must distinguish 360-degree image files from regular image files. The most straightforward approach is to check the metadata in files. The 360-degree-image-related metadata are added to the image file in different formats depending on the capturing device. Some capturing devices add metadata using the embeddedsoftware provided by the manufacturer. For other devices, the addition of metadata is carried out by external software packages. Different devices and software packages use different formats for embedding metadata. Capturing devices provide images in different file formats such as RAW, JPEG, PNG, BMP, GIF, TIFF, etc. The JPEG format, herein referred to as JPEG-1, has been market-dominant since its introduction to the market [7]. In the JPEG-1 image file format, application markers add metadata in images [8]. Image metadata play important roles in different aspects, such as image classification [9] and the digital investigation process [10]. Similarly, in omnidirectional images, metadata play a role in providing immersive and realistic feelings to the viewer. JPEG Systems, with multiple part specifications, is an international standard designed primarily for metadata storage and protection methods for compressed continuous-tone photographic contents [11]. Table 1 shows the status of each part of the JPEG Systems with the respective International Standardization Organization (ISO) project numbers. Part 5 defines the JPEG universal metadata box format (JUMBF). It defines special content type boxes and the syntax to embed or refer to generic metadata in the JPEG image files. JUMBF is a box-based universal format for various types of metadata [12]. Part 6 defines the use of the JPEG 360 Content Type JUMBF super box and defines the structure and syntax of an extensible markup language (XML) box for 360-degree image metadata [13]. The ISO/IEC 19566-6 (JPEG 360) is the standard for 360-degree images and builds upon the features of JUMBF, which provides a universal format to embed any type of metadata in any box-based file format. JUMBF itself is built on the ISO/IEC box file format 18477-3, and it provides compatibility with JPEG File Interchange Format (JFIF) on ISO/IEC 10918-5 [14]. Various smartphones and digital cameras have been released to easily capture and share our daily lives in the current consumer electronics market. However, since these devices store images along with metadata defined in different formats, it is necessary to convert the form of metadata included in the image into the form required by the