scholarly journals Quality Matters: A New Approach for Detecting Quality Problems in Web Archives

Author(s):  
Brenda Reyes Ayala ◽  
Jennifer McDevitt ◽  
James Sun ◽  
Xiaohui Liu

Since the practice of web archiving, or the act of preserving websites as historical, legal, and informational records, become more commonplace in the 2000s, web archives have become valuable sources for historical research. Unfortunately, many archived websites are of low quality and are missing crucial elements. In this paper, we examine the issue of quality and focus on visual correspondence, the similarity in appearance between the original website and its archived counterpart. We examine how the visual correspondence of an archived website can be measured using image similarity measures. Our results indicate that the Structural Similarity Index metric (SSIM) was able to successfully measure visual correspondence. If applied to the Quality Assurance process of an institution, this similarity metric could help web archivists quickly detect quality problems in their web archives, and fix them in order to create high-quality web archives. Depuis que la pratique de l'archivage Web, ou l'acte de préserver les sites Web en tant que documents historiques, juridiques et informatifs, est devenue plus courante dans les années 2000, les archives Web sont devenues des sources précieuses pour la recherche historique. Malheureusement, de nombreux sites Web archivés sont de mauvaise qualité et manquent d'éléments cruciaux. Dans cet article, nous examinons la question de la qualité et nous nous concentrons sur la correspondance visuelle, la similitude d'apparence entre le site Web d'origine et son homologue archivé. Nous examinons comment la correspondance visuelle d'un site Web archivé peut être mesurée à l'aide de mesures de similitude d'image. Nos résultats indiquent que la Structural Similarity Index metric (SSIM) a pu mesurer avec succès la correspondance visuelle. S'il est appliqué au processus d'assurance qualité d'une institution, cette indicateur de similitude pourrait aider les archivistes Web à détecter rapidement les problèmes de qualité dans leurs archives Web et à les résoudre afin de créer des archives Web de haute qualité.

2019 ◽  
Vol 16 (4) ◽  
pp. 0948
Author(s):  
Raheem Abdul Sahib Ogla

Steganography is defined as hiding confidential information in some other chosen media without leaving any clear evidence of changing the media's features. Most traditional hiding methods hide the message directly in the covered media like (text, image, audio, and video). Some hiding techniques leave a negative effect on the cover image, so sometimes the change in the carrier medium can be detected by human and machine. The purpose of suggesting hiding information is to make this change undetectable. The current research focuses on using complex method to prevent the detection of hiding information by human and machine based on spiral search method, the Structural Similarity Index Metrics measures are used to get the accuracy and quality of the retrieved image and to improve its perceived quality. The values of information measures are calculated through practical experiments of (perceptibility, robustness, capacity) by using interpolation technique and structural similarity measures. Experimental results show that the use of these measures (PSNR, MSE, and SSIM) has improved the image quality by 87% and has produced values of PSNR (38-41 dB), MSE = 0.6537 and SSIM= 0.8255. The results also demonstrate a remarkable progress in the field of hiding information and the increasing difficulty of detecting it by humans and machines.


2020 ◽  
Vol 25 (2) ◽  
pp. 86-97
Author(s):  
Sandy Suryo Prayogo ◽  
Tubagus Maulana Kusuma

DVB merupakan standar transmisi televisi digital yang paling banyak digunakan saat ini. Unsur terpenting dari suatu proses transmisi adalah kualitas gambar dari video yang diterima setelah melalui proses transimisi tersebut. Banyak faktor yang dapat mempengaruhi kualitas dari suatu gambar, salah satunya adalah struktur frame dari video. Pada tulisan ini dilakukan pengujian sensitifitas video MPEG-4 berdasarkan struktur frame pada transmisi DVB-T. Pengujian dilakukan menggunakan simulasi matlab dan simulink. Digunakan juga ffmpeg untuk menyediakan format dan pengaturan video akan disimulasikan. Variabel yang diubah dari video adalah bitrate dan juga group-of-pictures (GOP), sedangkan variabel yang diubah dari transmisi DVB-T adalah signal-to-noise-ratio (SNR) pada kanal AWGN di antara pengirim (Tx) dan penerima (Rx). Hasil yang diperoleh dari percobaan berupa kualitas rata-rata gambar pada video yang diukur menggunakan metode pengukuran structural-similarity-index (SSIM). Dilakukan juga pengukuran terhadap jumlah bit-error-rate BER pada bitstream DVB-T. Percobaan yang dilakukan dapat menunjukkan seberapa besar sensitifitas bitrate dan GOP dari video pada transmisi DVB-T dengan kesimpulan semakin besar bitrate maka akan semakin buruk nilai kualitas gambarnya, dan semakin kecil nilai GOP maka akan semakin baik nilai kualitasnya. Penilitian diharapkan dapat dikembangkan menggunakan deep learning untuk memperoleh frame struktur yang tepat di kondisi-kondisi tertentu dalam proses transmisi televisi digital.


Author(s):  
Sushma Tumkur Venugopal ◽  
Sriraam Natarajan ◽  
Megha P. Arakeri ◽  
Suresh Seshadri

Fetal Echocardiography is used for monitoring the fetal heart and for detection of Congenital Heart Disease (CHD). It is well known that fetal cardiac four chamber view has been widely used for preliminary examination for the detection of CHD. The end diastole frame is generally used for the analysis of the fetal cardiac chambers which is manually picked by the clinician during examination/screening. This method is subjected to intra and inter observer errors and also time consuming. The proposed study aims to automate this process by determining the frame, referred to as the Master frame from the cine loop sequences that can be used for the analysis of the fetal heart chambers instead of the clinically chosen diastole frame. The proposed framework determines the correlation between the reference (first) frame with the successive frames to identify one cardiac cycle. Then the Master frame is formed by superimposing all the frames belonging to one cardiac cycle. The master frame is then compared with the clinically chosen diastole frame in terms of fidelity metrics such as Dice coefficient, Hausdorff distance, mean square error and structural similarity index. The average value of the fidelity metrics considering the dataset used for this study 0.73 for Dice, 13.94 for Hausdorff distance, 0.99 for Structural Similarity Index and 0.035 for mean square error confirms the suitability of the proposed master frame extraction thereby avoiding manual intervention by the clinician. .


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