Joint Photographic Experts Group File Research Articles

Photo-Stacking Technique for Neuroanatomical High-Definition Photography and 3-Dimensional Modeling

Three-dimensional (3D) neuroanatomical knowledge is vital in neurosurgery. Technological advances improved 3D anatomical perception, but they are usually expensive and not widely available. The aim of the present study was to provide a detailed description of the photo-stacking technique for high-resolution neuroanatomical photography and 3D modeling. The photo-stacking technique was described in a step-by-step approach. The time for image acquisition, file conversion, processing, and final production was measured using 2 processing methods. The total number and file size of images are presented. Measures of central tendency and dispersion report the measured values. Ten models were used in both methods achieving 20 models with high-definition images. The mean number of acquired images was 40.6 (14-67), image acquisition time 51.50±18.8 s, file conversion time 250±134.6s, processing time 50.46±21.46s and 41.97±20.84s, and 3D reconstruction time was 4.29±0.74s and 3.89±0.60s for methods B and C, respectively. The mean file size of RAW files is 1010±452megabyte (MB) and 101.06±38.09MB for Joint Photographic Experts Group files after conversion. The mean size of the final image means size is 71.9±0.126MB, and the mean file size of the 3D model means is 37.4±0.516MB for both methods. The total equipment used was less expensive than other reported systems. The photo-stacking technique is a simple and inexpensive method to create 3D models and high-definition images that could prove valuable in neuroanatomy training.

A Novel Multimedia Player for International Standard—JPEG Snack

The advancement in mobile communication and technologies has led to the usage of short-form digital content increasing daily. This short-form content is mainly based on images that urged the joint photographic experts' group (JPEG) to introduce a novel international standard, JPEG Snack (International Organization for Standardization (ISO)/ International Electrotechnical Commission (IEC) IS, 19566-8). In JPEG Snack, the multimedia content is embedded into a main background JPEG file, and the resulting JPEG Snack file is saved and transmitted as a .jpg file. If someone does not have a JPEG Snack Player, their device decoder will treat it as a JPEG file and display a background image only. As the standard has been proposed recently, the JPEG Snack Player is needed. In this article, we present a methodology to develop JPEG Snack Player. JPEG Snack Player uses a JPEG Snack decoder and renders media objects on the background JPEG file according to the instructions in the JPEG Snack file. We also present some results and computational complexity metrics for the JPEG Snack Player.

Reversible data hiding in JPEG images based on zero coefficients and distortion cost function

Recently, reversible data hiding (RDH) in joint photographic experts group (JPEG) images has received a great deal of attention since the JPEG image is one of the most popularly used image formats nowadays. Generally in JPEG image, the quantized discrete cosine transform (DCT) coefficients with the value of zero are far more than those with nonzero coefficients. However, most existing methods are avoided to change these zero coefficients for fear of JPEG file size increase, and the designed distortion cost functions are not perfect. In this paper, we propose a new JPEG RDH method in which the numerous zero coefficients can be modified. Based on an improved distortion cost function, a strategy which can measure the distortion for each coefficient and select coefficient positions which are most suitable for embedding is proposed. With this strategy, zero coefficients are applied to data embedding and the embedding performance is improved. Experimental results have proved that the proposed method can effectively reduce the embedding distortion and increase the embedding capacity while maintaining a relative good file size.

Image Size Variation Influence on Corrupted and Non-viewable BMP Image

Image is one of the evidence component seek in digital forensics. Joint Photographic Experts Group (JPEG) format is most popular used in the Internet because JPEG files are very lossy and easy to compress that can speed up Internet transmitting processes. However, corrupted JPEG images are hard to recover due to the complexities of determining corruption point. Nowadays Bitmap (BMP) images are preferred in image processing compared to another formats because BMP image contain all the image information in a simple format. Therefore, in order to investigate the corruption point in JPEG, the file is required to be converted into BMP format. Nevertheless, there are many things that can influence the corrupting of BMP image such as the changes of image size that make the file non-viewable. In this paper, the experiment indicates that the size of BMP file influences the changes in the image itself through three conditions, deleting, replacing and insertion. From the experiment, we learnt by correcting the file size, it can able to produce a viewable file though partially. Then, it can be investigated further to identify the corruption point.

Blind JPEG steganalysis based on DCT coefficients differences

At recently, the most of the digital images are stored and transferred in their compressed format using discrete cosine transform (DCT)-based compression technique. DCT is one of the most important data compression technique due to the efforts from Joint Photographic Experts Group(JPEG). Blind steganalysis means how to detect the presence of the messages that are hidden using different types of steganography algorithms and has the ability to detect new unknown steganography algorithms. This paper presents blind steganalysis technique that can reliably detect the existence of messages hidden in JPEG files. In order to save the computation and memory cost, it is desirable to have image processing operations implemented directly in the DCT domain. The proposed method is based on extracting features directly from DCT domain through the analysis of differences between DCT coefficients before and after cropping. The extracted features are prepared as input to Support Vector Machine (SVM) to classify the image as stego (image that contain secret message) or clean (image that does not contain secret message). The experiments performed show that the proposed method yields better classification accuracy compared with other related works.

Reversible Data Hiding in JPEG Images

Among various digital image formats used in daily life, the Joint Photographic Experts Group (JPEG) is the most popular. Therefore, reversible data hiding (RDH) in JPEG images is important and useful for many applications such as archive management and image authentication. However, RDH in JPEG images is considerably more difficult than that in uncompressed images because there is less information redundancy in JPEG images than that in uncompressed images, and any modification in the compressed domain may introduce more distortion in the host image. Furthermore, along with the embedding capacity and fidelity (visual quality), which have to be considered for uncompressed images, the storage size of the marked JPEG file should be considered. In this paper, based on the philosophy behind the JPEG encoder and the statistical properties of discrete cosine transform (DCT) coefficients, we present some basic insights into how to select quantized DCT coefficients for RDH. Then, a new histogram shifting-based RDH scheme for JPEG images is proposed, in which the zero coefficients remain unchanged and only coefficients with values 1 and −1 are expanded to carry message bits. Moreover, a block selection strategy based on the number of zero coefficients in each $8\,\times \,8$ block is proposed, which can be utilized to adaptively choose DCT coefficients for data hiding. Experimental results demonstrate that by using the proposed method we can easily realize high embedding capacity and good visual quality. The storage size of the host JPEG file can also be well preserved.

Image Compression Impact on Quantitative Angiogenesis Analysis of Ovarian Epithelial Neoplasms

This study aims to investigate the impact of digital image compression on manual and semiautomatic quantification of angiogenesis in ovarian epithelial neoplasms (including benign, borderline, and malignant specimens). We examined 405 digital images (obtained from a previously validated computer-assisted analysis system), which were equally divided into 5 groups: images captured in Tagged Image File Format (TIFF), low and high compression Joint Photographic Experts Group (JPEG) formats, and low and high compression JPEG images converted from the TIFF files. Microvessel density counts and CD34 endothelial areas manually and semiautomatically determined from TIFF images were compared with those from the other 4 groups. Mostly, the correlations between TIFF and JPEG images were very high (intraclass correlation coefficients >0.8), especially for low compression JPEG images obtained by capture, regardless of the variable considered. The only exception consisted in the use of high compression JPEG files for semiautomatic microvessel density counts, which resulted in intraclass correlation coefficients of <0.7. Nonetheless, even then, interconversion between TIFF and JPEG values could be successfully achieved using prediction models established by linear regression. Image compression does not seem to significantly compromise the accuracy of angiogenesis quantitation in the ovarian epithelial tumors, although low compression JPEG images should always be preferred over high compression ones.

It's all about the format – unleashing the power of RAW aerial photography

Current one-shot, handheld Digital Still Cameras (DSCs) generally offer different file formats to save the captured frames: Joint Photographic Experts Group (JPEG), RAW and/or Tag(ged) Image File Format (TIFF). Although the JPEG file format is the most commonly used file format worldwide, it is incapable of storing all original data, something that also occurs, to a certain extent, for large TIFF files. Therefore, most professional photographers prefer shooting RAW files, often described as the digital photography's equivalent of a film negative. As a RAW file contains the absolute maximum amount of information and original data generated by the sensor, it is the only scientifically justifiable file format. In addition, its tremendous flexibility in both processing and post-processing also makes it beneficial from a workflow and image quality point of view. On the other hand, large file sizes, the required software and proprietary file formats remain hurdles that are often too difficult to overcome for many photographers. Aerial photographers who shoot with handheld DSCs should be familiar with both RAW and other file formats, as their implications cannot be neglected. By outlining the complete process from photon capture to the generation of pixel values, additionally illustrated by real-world examples, the advantages and particularities of RAW aerial photography should become clear.

Three‐dimensional reconstruction and visualization of the median nerve from serial tissue sections

The purpose of this study was to definitively implement the three-dimensional visualization of sensory and motor fascicles in the human median nerve by means of acetylcholinesterase (AChe) histochemical staining and under the assistance of the computer technology. One fresh human median nerve was harvested from a male adult cadaver. The median nerve was fixed at a special holder. Then, the whole holder was embedded and rapidly frozen in the liquid nitrogen. The processed median nerve was then cut coronally every 100 microm at a 20 microm thickness along its long axis in a sliding freezing microtome. The total number of sections was 4,650 slices. All sections were stained with the AChe histochemical method. The stained sections were scanned and saved as Joint Photographic Experts Group files. These images with positively and negatively stained sections were acquired to an Intel dual Pentium computer. The Adobe Photoshop CS2 software was used to compare the reference points of images before and after staining. The two-dimensional intraneural microstructure database of median nerve was then acquired. A software of 3D nerve visualization system was developed. With the 3D nerve visualization system, the 3D visualization result of intraneural microstructure of median nerve was created. The findings may provide more accurate and detailed anatomic information for nerve repairs, specifically for the fascicular nerve repairs. The 3D nerve visualization technique may have potential for future studies of topography of peripheral nerve. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

A five-step approach to digital image manipulation for the radiologist.

Digital manipulation of images plays a key role in development of multimedia presentations. Five basic steps to digitizing images and preparing them for publication and computer presentation are scanning, correction, editing and labeling, saving files, and producing final output. These steps can be completed with commercially available hardware and image manipulation software (eg, Photoshop). The higher the quality of the original scanned image, the more image data there will be to edit: A good image cannot be created from an inferior scan. The most important functions for properly scanning images are size, resolution, and color. Resolutions of 300 ppi and 72 ppi should be used for print publication and computer presentations, respectively. The higher resolution image has the larger file size. The scanned image should be saved as a TIFF (tagged image file format), which is an uncompressed file type used for printed images. The Joint Photographic Experts Group (JPEG) format compresses the size of the image file but also reduces image quality. The JPEG format is a good choice if a small file size is needed, such as in Web and PowerPoint presentations. If the user needs to save an image as a JPEG file, the image should be edited first and then saved once in JPEG format. With Photoshop, the user can rotate and crop an image; adjust its brightness, contrast, and color; remove unwanted patient information, dust, and scratches; and add text and symbol labels to enhance images for teaching purposes. Digital manipulation can be fast and effective if the user has some basic knowledge and tools.

The effects of different image file formats and image-analysis software programs on dental radiometric digital evaluations.

To determine if variations in radiodensity data are introduced by lossy Joint Photographic Experts Group (JPEG) compression and/or the use of three software programs. An occlusal film with an aluminium step wedge was exposed, processed and digitized under standard conditions. Before the image was saved, the coordinates and the gray-scale value for each pixel in a 20 x 20 pixel area near the middle of the thickest step were recorded. These pixel coordinates and gray-scale values served as Truth 1. In addition, a digital simulated-radiographic image with assigned gray-scale values for each pixel was created and served as Truth 2. The digital data for the scanned radiograph and the simulated radiograph were saved as Tagged Image File Format (TIFF) and lossy JPEG files. Each file was opened with three software programs and the gray-scale values of homologous pixels were recorded. For these pixels in each image type, the mean gray-scale values and standard deviations were calculated. The pixel gray-scale values for each homologous pixel were also individually compared. When the TIFF images were opened with the three software programs, one program resulted in gray-scale values that were not concordant with truth. All JPEG images resulted in gray-scale values that were not concordant with truth. One software program added a column of 0s to data files. Lossy JPEG compression introduced potentially deleterious variations to radiodensity data, and at least two of the software programs performed JPEG image decompression differently.