An interview with Judith Redi

Judith Redi was interviewed by Michael Riegler.


Judith Redi (F) is Assistant Professor at the Multimedia Computing group of TUD. She is also Faculty fellow at the Benelux Center for Advanced Studies of IBM, and since 2016, she is affiliated as a Researcher to the Distributed and Interactive Systems group of CWI. Dr. Redi received her PhD from the University of Genoa in 2010; her thesis, funded by Philips research and focusing on the design of intelligent tools for automated display quality assessment, received the ASING award for the best ICT PhD thesis 2010. Dr. Redi’s current work focuses on the optimization of multimedia delivery chains from a user-centered perspective, i.e., towards the maximization of users’ Quality of Experience. This implies the understanding (through empirical research) and modelling (via learning machines and Multimedia Signal Processing) of perceptual, cognitive, and affective mechanisms involved in the appreciation of multimedia experiences. For this research, she was granted a VENI award (personal grant) by the Dutch research funding agency NWO.

Dr. Redi has served as Area Chair for ACM Multimedia 2016, TPC chair of QoMEX 2015, and co-chair and main organizer for a number of ACMMM workshops including CrowdMM and AltMM. In 2017, she will serve as General Co-Chair of ACM TVX, and she has recently been elected Working group leader for the Training WG of Qualinet, the European Network for research on Quality of Experience.

Michael Alexander Riegler is a PhD student at Simula Research Laboratory. He received his master degree from the Klagenfurt University with distinction. His master thesis was about large scale content based image retrieval. He wrote it at the Technical University of Delft under the supervision of Martha Larson. He is a part of the EONS project and the DigSys pre-project at the Media Performance Group. His research interests are endoscopic video analysis and understanding, image processing, image retrieval, parallel processing, gamification and serious games, crowdsourcing, social computing and user intentions. Furthermore he is involved in several initiatives like the MediaEval Benchmarking initiative for Multimedia Evaluation.

Describe your journey into computing from your youth up to the present. What foundational lessons did you learn from this journey? Why were you initially attracted to multimedia?

Dr. Judith Redi

Dr. Judith Redi

My path to multimedia was, let’s say, non-linear. I grew up in the Italian educational system, which up until university, is somewhat biased towards social sciences and humanities. My family was not one of engineers/scientists either, and never really encouraged me to look at the technical side of things. Basically, I was on a science-free educational diet until university. On the other hand, my hometown used to host the headquarters of Olivetti (may remember fancy typewriters and early personal computers?). This meant that at a very young age I had a PC at home and at school, and could use it (as a “user” on the other side of the systems we develop; I had no clue about programming).

When the time came to choose a major at university, I decided to turn the tables, a bit as a provocative action towards my previous education/mind-set, and a bit because I was fascinated by the perspective of being able to design and build future technologies. So, I picked computer engineering, perhaps inspired by my hometown technological legacy. I immediately got fascinated by artificial intelligence, and its potential to make machines more human-like (I still tell all my bachelor students that they should have a picture of Turing on their desk or above their bed). I specialized in machine learning and applied it to cryptanalysis within my master thesis. I won a scholarship to continue that research line in a PhD project at the University of Genoa. And then Philips came along, and multimedia with it.

At the time (2007), Philips was still manufacturing displays, and to stay ahead of the competition, they had to make sure their products would deliver to users the highest possible visual quality. They had algorithms to enhance image quality, but needed a system able to understand how much enhancement was needed, and of which type (sharpening? De-noising?), based on the analysis on the incoming video signal. They wanted to try a machine-learning approach to this issue, and referred to my group for collaboration. I picked up the project immediately: the goal was to model human vision (or at least the processes underlying visual quality perception), which implied not only developing new intelligent systems at the intersection between Signal Processing and Machine Learning, but also to learn more about the users of these systems, their perception and cognition. It was the fact that it would allow me to adopt a user-centred approach, closing the loop back to my social science-oriented education, that made multimedia so attractive to me. So, I left cyber-security, embraced Multimedia, and never left since.

One Philips internship, a best PhD thesis award and a Postdoc later, I am still fascinated by this duality. Much has changed in multimedia delivery, with the shift from linear TV to on-demand content consumption, video streaming accounting for 70% of the internet traffic nowadays, and the advent of Ultra High Definition solutions. User expectations in terms of Quality of Experience (QoE) increase by the day, and they are not only affected by the amount of disruptions (due to encoding, untrustworthy transmissions, rendering inaccuracies) in the delivered video, but also relate to content semantics and popularity, user affective state, environment and social context. The role of these factors on QoE is yet to be understood, let alone modelled. This is what I am working on at TU Delft, and is a long term plan, so I guess I won’t be leaving multimedia any time soon.

I’d say it’s too early for me to draw “foundational lessons” worth sharing from my journey. I guess there are a few things, though, that I figured out along the years, and that may be worthwhile mentioning:

  1. Seemingly reckless choices may be the best decisions you have ever made. Change is scary, but can pay off big time.

  2. Luck exists but hard work is a much safer bet

  3. Keep having fun doing your research. If you’re not having fun anymore, see point (1).

Tell us more about your vision and objectives behind your current roles? What do you hope to accomplish and how will you bring this about?

As a researcher, I have been devoting most of my efforts to understanding multimedia experiences and steer their optimization (or improvement) towards a higher user satisfaction (with the delivery system). On the longer term, I want broaden this scope, to make an even bigger impact on people’s life: I want to go beyond quality of experience and multimedia enjoyment, and target the optimization (or at least improvement) of users’ well-being.

For the past four years, I have been working with Philips Research on an Ambient Assisted Living system able to (1) sense the mood of a user in a room and (2) adapt the lighting in the room to alleviate negative moods (e.g., sadness, or anxiety), when sensed. We were able to show that the system can successfully counter negative moods in elderly users (see our recent PLoS One publication if you are interested), without the need of human intervention. The thing is, negative affective states are experienced by elderly (but by younger people too, according to recent findings) quite often, and most times, a fellow human (relative, friend, caretaker) is not available to comfort the person. My vision is to build systems that, based on the unobtrusive sensing of users’ affective states, can act upon the detection of negative states and relieve the user just as a human would do.

I want to design “empathic technology”, able to provide empathic care, whenever human care is not within reach. Challenges are multiple here. First, (long-term) affective states (such as mood, which is more constant and subtle than emotion) are to be sensed. (Wearable) sensors, cameras, or also interaction with mobile devices and social media can provide relevant information here. Empathic care can then be conveyed through ambient intelligence solutions, but also by creative industries products, ranging from gaming to intelligent clothing, to, of course, Multimedia technology (think about empathic recommender systems, or videotelephony systems that are optimized to maximize the affective charge of the communication). This type of work is highly multidisciplinary (involving multimedia systems, affective computing, embedded systems and sensors, HCI and certainly psychology), and the low-hanging fruits are not many. But I’d like this to be my contribution to make the world a better place, and I am ready to take up the challenge.

Can you profile your current research, its challenges, opportunities, and implications?

Internet-based video fruition has been reality for a while, yet it is constantly growing. Cisco’s forecasts see video delivery to account for 79% of the overall internet consumer traffic by 2018 (this is equivalent to one million minutes of video crossing IP networks every second). As the media fruition grows, so do user expectations in terms of Quality of Experinece (see the recent Conviva reports!). And, future multimedia will have to be optimized for multiple, more immersive (plenoptic, HDRi, ultra-high definition) devices, both fixed and mobile. Moore’s law and broadband speed alone won’t do the job. Resources and delivery mechanisms have to be optimized on a more application- and user-specific basis. To do so, it will be essential to be able to measure (unobtrusively) the extent to which the user deems the video experience to be of a high quality.

In this context, my work aims to (1) understand the perceptual, cognitive and affective processes underlying user appreciation for multimedia experiences, and (2) model these processes in order to automatically assess the delivered QoE, and, when applicable, enhance it. It is important here to bear in mind that multimedia quality of experience cannot be considered to depend solely on the presence (absence) of visual/auditory impairments introduced by technology limitations (e.g., packet loss errors or blocking artifacts from compression). Although that’s been the most common approach to QoE assessment and optimization, it is not sufficient anymore. The appearance of social media and internet-based delivery has challenged the way media are consumed: we don’t deal with passive observers anymore, but with users that select specific videos, to be delivered on specific devices, in any type of context. Elements such as semantics, user personality, preferences and intent, and socio- cultural context of fruition come into play, that have never been investigated (let alone modelled) for delivery optimization. My research focuses on integrating these elements in QoE estimation, to enable effective, personalized optimization.

The challenges are countless: user and context characteristics have to be quantified and modelled, to be then integrated with the video content analysis to deliver a final quality assessment, representing the experience as it would be perceived by that user, in that context, given that specific video. Before that, which user and context factors impact QoE is to be determined (to date, there is not even agreement on a taxonomy of these factors). Adaptive streaming protocols make it possible to implement user- and context- aware delivery strategies, the willingness of users to share personal data publicly can lead to more accurate user models, and especially crowdsourcing and crowdsensing can support the systematic study of the influence that context and user factors have on the overall QoE.

How would you describe the role of women especially in the field of multimedia?

Just like for their male colleagues (would you ask them to describe the role of men in multimedia?), the role of women in multimedia is:

  1. to push the boundaries of science, knowledge and practice in the field, doing amazing research that will make the world a better place
  2. to train new generations of brilliant engineers and scientists that will keep doing amazing research to make the world an even better place and
  3. serve the community as professionals and leaders to steer the future amazing research that will go on making the wold better and better.

I’d say the first two points are covered. The third, instead, may be implemented a bit better in practice, as there is a general lack of representativeness of women at a leadership level. The reasons for this are countless. They go from the lack of incoming talent (traditionally girls are not attracted to STEM subjects, perhaps for socio-cultural reasons), to the so-called leaking pipeline, which sees talented women leaving demanding yet rewarding careers too early, to an underlying presence of the impostor syndrome, that sometimes prevents women from putting their name forward for given roles. The solution is not necessarily in quotas (although I understand the reasoning behind the need for quotas, I think they are actually making women’s life more difficult – there is an underlying feeling that “women have it all easy these days” that makes work relationships more suspicious and ends up making women have to work three times as hard to show that they actually deserve what they accomplished), but rather in coaching and dedicated sponsorship of talent since the early stages.

How would you describe your top innovative achievements in terms of the problems you were trying to solve, your solutions, and the impact it has today and into the future?

The methods that I developed for subjective image quality assessment have been adopted within Philips research and their evolution to video quality assessment is now under evaluation of the Video Quality Experts Group to be advised as an alternative methodology to the standard ACR and paired comparison. The research that I carried out on the suitability of crowdsourcing for subjective QoE testing and adaptation of traditional lab-based experimental designs to crowdtesting is now included in the Qualinet white paper on Best practices for crowdsourced QoE, and has helped in better understanding the potential of this tool for QoE research (and the risks involved in its use). This research is also currently feeding new ITU-T recommendations on the subject. The models that I developed for objective QoE estimation have been published in top journals and pose the basis for a more encompassing and personalized QoE optimization.

Over your distinguished career, what are your top lessons you want to share with the audience?

Again, I am not sure whether I am yet in the position of giving advice and/or sharing lessons, but here are a couple of things:

  1. Be patient and long-sighted. Going for research that pays off on the short term is very appealing, especially when you are challenged with job insecurity (been there, done that). But it is not a sustainable strategy, you can’t make the world a better place with your research if you don’t have a long term vision, where all the pieces fit together towards a final goal. And on the long term, it’s not fun either.

  2. Be generous. Science is supposed to move forward as a collaborative effort. That’s why we talk about a “scientific community”. Be generous in sharing your knowledge and work (open access, datasets, code). Be generous in providing feedback, to your peers (be constructive in your reviews!) and to students. Be generous in helping out fellow scientists and early stage researchers. True, it is horribly time consuming. But it is rewarding, and makes our community tighter and stronger.

For girls, watch Sheryl Sandberg’s TED talk, do participate to the Grace Hopper Celebration of Women in Computing, don’t be afraid to come to the ACMMM women’s lunches, they are a lot of fun. Actually, these are good tips for boys too.

For the rest just watch The last lecture of Randy Pausch because he said it all already and much better than I could ever do.

If you were conducting this interview, what questions would you ask, and then what would be your answers?

Q: Why should one attend the ACMMM women’s lunch?

A: If you are a female junior member of the community, do attend because it will give you the opportunity to chat with senior women who have been around for a while, and can tell you all about how they got where they are (most precious advice, trust me). If you are a female senior member of the community, do attend because you could meet some young, talented researcher that needs some good tips from you, and you should not keep all your valuable advice for yourself :). If you are a male member of the community, you should attend because we really need to initiate some constructive dialogue on how to deal with the problem of low female representation in the community (because it is a problem, see next question). Being this a community problem (and not a problem of females only), we need all members of the community to discuss it.

Q: Why do we need more women in Multimedia?

A: Read this or this, or just check the Wikipedia page on women in STEM.

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