This document summarizes Daniel Sanchez's final project presentation on lossless JPEG transcoding. It discusses (1) the problem with reencoding JPEG images, which introduces errors, (2) the development of a full-featured MATLAB JPEG codec, and (3) two methods for lossless transcoding - a decoder/encoder approach that corrects coefficient estimations, and a rotation approach that directly manipulates blocks in the spatial domain. Results show lossless transcoding prevents quality degradation compared to lossy reencoding or rotation. Applications include image editing, basic transformations, and transmission/storage.
This presentation is meant to discuss the basics of video compression like DCT, Color space conversion, Motion Compensation etc. It also discusses the standards like H.264, MPEG2, MPEG4 etc.
This presentation is meant to discuss the basics of video compression like DCT, Color space conversion, Motion Compensation etc. It also discusses the standards like H.264, MPEG2, MPEG4 etc.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
2. 2
Overview
The problem of JPEG transcoding
Full-featured MATLAB JPEG codec
Lossless transcoder
Lossless rotation
3. 3
The problem of JPEG transcoding
Basic JPEG decoder/encoder block diagrams:
Reencoding introduces errors because of the color
model conversions (YCbCr<->RGB)
RGB->YCbCr
Level shifting
DCT Q
DPCM DC Huffman
ZigZag AC Huffman
JPEG
File
RGB
Image
JPEG Encoder
DC
AC
Level shifting
YCbCr->RGB
IDCTIQ
IDPCMDC Huffman
DeZigZagAC Huffman
JPEG Decoder
DC
AC
RGB
Image
JPEG
File
4. 4
Implementing a JPEG codec in MATLAB
Extends the MATLAB JPEG Toolbox by Phil Sallee
• http://redwood.ucdavis.edu/phil/demos/jpegtbx/
• Includes functions that cover the more tedious parts of
the codec
Works with most images!
• Full color, arbitrary size,…
• Some restrictions in subsampling and color models
RGB->YCbCr
Level shifting DCT Q
DPCM DC Huffman
ZigZag AC Huffman
JPEG
File
RGB
Image
JPEG Encoder
DC
AC
Implemented Provided by toolbox
5. 5
Example of lossy reencoding
Original image Error after reencoding (x15)
SNR=25.1dB
6. 6
Lossless JPEG transcoder [1]
How to modify decoder/encoder?
RGB->YCbCr
Level shifting
DCT Q
DPCM DC Huffman
ZigZag AC Huffman
JPEG
File
RGB
Image
DC
AC
Level shifting
YCbCr->RGB
IDCTIQ
IDPCMDC Huffman
DeZigZagAC Huffman
Lossy JPEG Transcoder
DC
AC
RGB
Image
JPEG
File
Reencoded coefficients are
an estimation of the original ones
-> Correct that estimation!
8. 8
Results of lossless transcoding
Original image Transcoded image Difference coefficients
(contrast )↑↑
Lossy reencoding: SNR = 33.2 dB
Lossless transcoding: SNR = ∞
9. 9
Lossless rotation
Different approach: Operate on blocks directly
• No need to requantize -> Lossless
• Faster than decoding/encoding
To rotate an image (90º counterclockwise):
• Rotate whole blocks
(without modifying content)
• Perform the transformation
G(u,v)=F(v,u)(-1)v
on each block
□ This rotates the contents in the spatial domain!
• Transpose quantization matrices (they are not symmetric in
general!)
1 2 3
4 5 6
7 8 9
3 6 9
2 5 8
1 4 7
11. 11
Results of lossless rotation [2]
Losslessly rotated
image
Those strange
manipulations
actually work!
12. 12
Results of lossless rotation [3]
This time SNR=18.1 dB
Lossy rotation degrades the quality much more than reencoding!
Error when lossy rotation is applied 4 times
13. 13
Applications of lossless transcoding
Image editing (allows editors to work with lossy
compressed images without degrading quality)
Image rotation and other basic transformations
(cropping, flipping,…)
Image transmission/storage
