|By Jim O'Neil||
|August 6, 2012 08:07 AM EDT||
In the last post, I discussed the structure of a notification template and the mechanics for providing the various bit of information in that template. As you know, many of the notification templates can include one or more images, and that brings up a host of configuration options that I didn’t have a chance to get into last time. This post will fill in the gaps and provide insight into three main topics:
I’ll close with a quick list of not-so-obvious features and behaviors that will hopefully save you some time as you plan out your strategy for supporting images as part of notifications used within your application.
There are two overarching constraints for images used within notifications:
- Images used in notifications must be in one of three formats: .png, .jpg/.jpeg, or .gif, and the format must match the extension.
- Images for notifications must be no larger than 200 KB and 1024 x 1024 in dimension.
Beyond that and depending on the device size and characteristics, images within Windows 8 may be scaled to one of four proportions (80%, 100%, 140% and 180%). Since the notification image formats supported are all raster formats (versus vector-based) you cannot rely on the scaling to result in clear, crisp imagery, so it’s recommended that you provide artwork to accommodate all four scaling factors.
The table below (which is adapted from the App images topic on MSDN) shows most of the sizes [see note] needed for tile and toast notifications as well as the (optional) badge logo for the start screen. Only those images highlighted in red (100% size for logo and small logo) are required and must be supplied in the app manifest (as .jpg/jpeg or .png formats [see note]). Other sizes are optional and if not provided will be generated by scaling the default 100% image.
appxmanifest Image Name
80% [see note] 100% 140% 180% Logo
(default square tile)
120x120 150x150 210x210 270x270 Small logo
(tile under semantic zoom,
tile and toast branding) [see note]
24x24 30x30 42x42 54x54 Wide logo
(default wide tile)
248x120 310x150 434x210 558x270 Badge Logo [see note]
24x24 33x33 43x43
Images used for notifications can be stored in one of three places:
- within the app package, using the
ms-appx:///prefix to a directory in your deployed application (this is the default).
- within local storage, using the
ms-appdata:///localprefix to a directory within local storage. Note that images in temporary and roaming application data storage cannot be used.
- on the web, using an
httpsURI that serves up image content (this requires that the application declare Internet client capability in its manifest).
Within the template XML you can specify the entire image URI or use paths relative to the baseUri value specified within the template. The baseUri can be set for either the visual (tile | toast) tag or the binding tag (tile | toast), with the latter overriding the former when provided.
App Package Images
Here, for example, is a code snippet from the App tiles and badges sample showing the use of an image within the local application package:
var tileXml = Windows.UI.Notifications.TileUpdateManager.getTemplateContent( Windows.UI.Notifications.TileTemplateType.tileWideImageAndText01); // get the text attributes for this template and fill them in var tileTextAttributes = tileXml.getElementsByTagName("text"); tileTextAttributes.appendChild(tileXml.createTextNode( "This tile notification uses ms-appx images")); // get the image attributes for this template and fill them in var tileImageAttributes = tileXml.getElementsByTagName("image"); tileImageAttributes.setAttribute("src", "ms-appx:///images/redWide.png");
Local Storage Images
The code for accessing an image in local storage is very similar, differing only by the addressing scheme:
Here the image is located in a subdirectory called images at the location returned by ApplicationData.localFolder; when I ran an excursion of the sample app using this access mechanism, the image was served from:
Images in the Cloud
One option to consider when architecting your application is leveraging the cloud for external resources that your application uses. If you place images and other content on the web or in the cloud, you’ve decoupled those resources from your application, and by doing so you can freshen the look and feel of your application without publishing a new version of your application or requiring the end users to get an update.
Windows Azure, Microsoft’s public cloud offering, can be an incredibly convenient and cost effective way to manage the images you’re using for your notifications. The easiest way to serve image content from Windows Azure is via blob storage which provides highly scalable and highly available storage of unstructured data at one of eight Windows Azure data centers worldwide. A Content Delivery Network (currently comprising 24 nodes) is also available to improve performance and user experience for end-users who aren’t located near a data center.Keep in mind there are some caveats when using cloud or web hosted images:
- The most obvious is that if the machine lacks network connectivity, the image won't be available and the notification will not be sent.
- Web images are cached, so an update to the image in the cloud may not be immediately reflected on the client. If the cache is full, images will be removed in a policy opaque to the developer. Additionally the system will clear the cache when
- The application is uninstalled, or
- The user clears personal information from all of her application tiles (via the Settings flyout on the Start screen).
The system will comply with caching and expiration headers in the HTTP response. Those headers are not configurable in Windows Azure storage alone, but a web service can be configured and hosted on Windows Azure to support this.
- The cloud isn't free! While there are no-cost options (like the 90-day trial and MSDN subscriptions), you ultimately may end up paying for the storage and the transactions (HTTP GET requests) that are made by your application. The complete pricing details are available at the Azure pricing page, but it’s very likely you'll be able to support a popular Windows 8 application for dollars if not pennies a month.
The elephant in the room thus far in this post is that all the samples I’ve shown above refer to a single image of some unknown size, and I appear to have ignored the advice to provide four different image sizes (80%, 100%, 140% and 180%) scale to provide the best user experience!
It turns out that there’s a bit of magic happening behind the scenes to make managing the combination of image sizes and contrast mode (don’t forget there’s are high-contrast white and high-contrast black options too!). The amount of ‘magic’ depends on the image source, so I’ll cover them independently below.
App Package Images
When you provide images as part of your application package, a naming convention can be leveraged which enables you to specify one base image name (say in the notification template image src attribute) yet the system automatically selects a file with a modified name based on the current scale factor and contrast mode.
For instance, while the code sample above refers to
redWide.png, the application can deliver a slew of versions that vary by scale factor, contrast mode, culture (e.g., en-US versus zh-CN), and several other resource qualifiers.
A file named
redWide.scale-140.png, if available, would be used in the samples above – in lieu of scaling the default image – whenever there was a request for
redWide.pngand the current scale required was 140%. Your code doesn’t need to do a thing!
If you had a special version of the tile just for those in French locales, you could name that image,
redWide.lang-FR-fr_scale-140.png. (Note the lang prefix to the BCP-47 language identifier)
redWide.scale-180_contrast-black.pngwould be used when the contrast mode is black and an image scaled to 180% is needed. By the way,
You can also arrange the images in subdirectories, to provide a myriad of customization options. Take, for example, the following directory structure.
If the application were run on a US based system, but the user selected a black high contrast theme, a reference for
welcome.png for a tile notification on a typical laptop would pick the variant on Line 8. Someone running the applications with his locale set to Japan on a high-resolution device would see the image file associated with Line 17.
Unfortunately, none of the conventions supported for app package images are supported when using local images (the
ms-appdata:///local namespace), but you could implement similar semantics programmatically using the following Windows APIs:
|Attribute||Windows Class or Property||Values|
|Language||ApplicationLanguage.languages||a list of BCP-47 codes corresponding to the applications supported languages (see ���How to manage language and region” for details)|
|Contrast Scheme [see note]||AccessibilitySettings.highContrast
”High Contrast White”
”High Contrast Black”
”High Contrast #1”
”High Contrast #2”
|Home Region||GlobalizationPreferences.homeGeographicRegion||BCP-47 subtag code corresponding to user’s Region preference in Control Panel|
Images in the Cloud
Both the tile schema and the toast schema include an optional attribute called addImageQuery, on the visual, binding, and image elements (the value set on the deepest element overriding those above it). When addImageQuery is set to true, HTTP/HTTPS requests made for images will have a query string appended consisting of the following three name value pairs:
|Attribute||Query String Name||Query String Value|
|Contrast Scheme [see note]||
Here for instance is an HTTP request made for the
The good news is that you don’t have to figure out which variant of an image is being requested – that information is available in the query parameters; the bad news is that you have to build your own web service to inspect those parameters and serve up the correct image in response. You can’t just use the blob storage mechanism shown above, because those query parameters aren't automatically interpreted by Windows Azure blob storage, but you can still use Windows Azure with a little bit of code (PHP, ASP.NET, Node.js, or essentially any implementation of a web service that will run on Windows).
- 80% images are used on tiles for some combinations of screen size and resolution.
- Size specifications haven’t been published for images that appear on toast or that do not fill the entire tile, such as the template samples below. In most cases, these will be photographic images which scale fairly well (using the Fant algorithm internally). You could measure the sizes empirically, but if you create images that work for 180% scale they should also scale down well for the other three factors.
- Default images (those declared in your app manifest) must be .png or .jpg/.jpeg format, but you can use .gif in your toast and tile notification templates.
- If an image is of the wrong format or not available (such as a image hosted on the Web when the client is not connected), the notification will not be sent.
- The branding element is taken from the small logo in your manifest. For tiles it appears in the bottom left and for toast in the bottom right. In the tile schema you can use text, logo, or no branding; in the toast schema, the branding attribute is not used and you will always see the logo.
- The badge logo must be monochromatic.
- if you don’t supply multiple images to accommodate scaling, try to create images with dimensions that are a multiple of 5 as they won’t experience pixel shifting during scaling.
- The Visual Studio simulator is an awesome way to test out tile behavior under different resolutions and contrast modes, but be aware, you’ll have to restart your debug session in the simulator if your change in resolution results in loading a different version of the image.
- PC Settings > Ease of Access (accessible via the Settings charm) includes a switch to toggle High Contrast mode; however, since there are four high contrast modes, you’ll need to use the desktop Control Panel option to pick one. Once you’ve selected the contrast mode there, PC Settings > Ease of Access will use that High Contrast mode when you toggle the option.
- Windows supports four high contrast modes (White, Black, #1, and #2), and these map to four overlapping resource types: standard, high, black, and white as follows:
Contrast Setting in Control Panel Applicable Resource Qualifiers
ms-contrastQuery Parameter Value
High Contrast White
white High Contrast Black
black High Contrast #1
black High Contrast #2
The recent trends like cloud computing, social, mobile and Internet of Things are forcing enterprises to modernize in order to compete in the competitive globalized markets. However, enterprises are approaching newer technologies with a more silo-ed way, gaining only sub optimal benefits. The Modern Enterprise model is presented as a newer way to think of enterprise IT, which takes a more holistic approach to embracing modern technologies.
May. 25, 2015 11:00 PM EDT Reads: 6,105
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. 8th International Big Data Expo, co-located with 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. As advanced data storage, access and analytics technologies aimed at handling high-volume and/or fast moving data all move center stage, aided by the cloud computing bo...
May. 25, 2015 08:45 PM EDT Reads: 2,000
Every day we read jaw-dropping stats on the explosion of data. We allocate significant resources to harness and better understand it. We build businesses around it. But we’ve only just begun. For big payoffs in Big Data, CIOs are turning to cognitive computing. Cognitive computing’s ability to securely extract insights, understand natural language, and get smarter each time it’s used is the next, logical step for Big Data.
May. 25, 2015 08:00 PM EDT Reads: 2,278
There's no doubt that the Internet of Things is driving the next wave of innovation. Google has spent billions over the past few months vacuuming up companies that specialize in smart appliances and machine learning. Already, Philips light bulbs, Audi automobiles, and Samsung washers and dryers can communicate with and be controlled from mobile devices. To take advantage of the opportunities the Internet of Things brings to your business, you'll want to start preparing now.
May. 25, 2015 07:00 PM EDT Reads: 5,902
Enterprises are fast realizing the importance of integrating SaaS/Cloud applications, API and on-premises data and processes, to unleash hidden value. This webinar explores how managers can use a Microservice-centric approach to aggressively tackle the unexpected new integration challenges posed by proliferation of cloud, mobile, social and big data projects. Industry analyst and SOA expert Jason Bloomberg will strip away the hype from microservices, and clearly identify their advantages and d...
May. 25, 2015 07:00 PM EDT Reads: 2,226
In a world of ever-accelerating business cycles and fast-changing client expectations, the cloud increasingly serves as a growth engine and a path to new business models. Dynamic clouds enable businesses to continuously reinvent themselves, adapting their business processes, their service and software delivery and their operations to achieve speed-to-market and quick response to customer feedback. As the cloud evolves, the industry has multiple competing cloud technologies, offering on-premises ...
May. 25, 2015 06:00 PM EDT Reads: 4,233
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the...
May. 25, 2015 05:30 PM EDT Reads: 4,442
The OpenStack cloud operating system includes Trove, a database abstraction layer. Rather than applications connecting directly to a specific type of database, they connect to Trove, which in turn connects to one or more specific databases. One target database is Postgres Plus Cloud Database, which includes its own RESTful API. Trove was originally developed around MySQL, whose interfaces are significantly less complicated than those of the Postgres cloud database. In his session at 16th Cloud...
May. 25, 2015 05:00 PM EDT Reads: 1,722
Over the years, a variety of methodologies have emerged in order to overcome the challenges related to project constraints. The successful use of each methodology seems highly context-dependent. However, communication seems to be the common denominator of the many challenges that project management methodologies intend to resolve. In this respect, Information and Communication Technologies (ICTs) can be viewed as powerful tools for managing projects. Few research papers have focused on the way...
May. 25, 2015 05:00 PM EDT Reads: 2,001
As the world moves from DevOps to NoOps, application deployment to the cloud ought to become a lot simpler. However, applications have been architected with a much tighter coupling than it needs to be which makes deployment in different environments and migration between them harder. The microservices architecture, which is the basis of many new age distributed systems such as OpenStack, Netflix and so on is at the heart of CloudFoundry – a complete developer-oriented Platform as a Service (PaaS...
May. 25, 2015 05:00 PM EDT Reads: 1,876
SAP is delivering break-through innovation combined with fantastic user experience powered by the market-leading in-memory technology, SAP HANA. In his General Session at 15th Cloud Expo, Thorsten Leiduck, VP ISVs & Digital Commerce, SAP, discussed how SAP and partners provide cloud and hybrid cloud solutions as well as real-time Big Data offerings that help companies of all sizes and industries run better. SAP launched an application challenge to award the most innovative SAP HANA and SAP HANA...
May. 25, 2015 04:00 PM EDT Reads: 3,358
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading in...
May. 25, 2015 04:00 PM EDT Reads: 3,030
P2P RTC will impact the landscape of communications, shifting from traditional telephony style communications models to OTT (Over-The-Top) cloud assisted & PaaS (Platform as a Service) communication services. The P2P shift will impact many areas of our lives, from mobile communication, human interactive web services, RTC and telephony infrastructure, user federation, security and privacy implications, business costs, and scalability. In his session at @ThingsExpo, Robin Raymond, Chief Architect...
May. 25, 2015 03:00 PM EDT Reads: 4,371
The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce software that is obsolete at launch. DevOps may be disruptive, but it is essential. The DevOps Summit at Cloud Expo – to be held June 3-5, 2015, at the Javits Center in New York City – will expand the DevOps community, enable a wide...
May. 25, 2015 03:00 PM EDT Reads: 2,485
There is no question that the cloud is where businesses want to host data. Until recently hypervisor virtualization was the most widely used method in cloud computing. Recently virtual containers have been gaining in popularity, and for good reason. In the debate between virtual machines and containers, the latter have been seen as the new kid on the block – and like other emerging technology have had some initial shortcomings. However, the container space has evolved drastically since coming on...
May. 25, 2015 02:45 PM EDT Reads: 1,823
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Ar...
May. 25, 2015 02:00 PM EDT Reads: 5,014
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding bu...
May. 25, 2015 02:00 PM EDT Reads: 4,605
Cloud Expo, Inc. has announced today that Andi Mann returns to DevOps Summit 2015 as Conference Chair. The 4th International DevOps Summit will take place on June 9-11, 2015, at the Javits Center in New York City. "DevOps is set to be one of the most profound disruptions to hit IT in decades," said Andi Mann. "It is a natural extension of cloud computing, and I have seen both firsthand and in independent research the fantastic results DevOps delivers. So I am excited to help the great team at ...
May. 25, 2015 02:00 PM EDT Reads: 2,062
All major researchers estimate there will be tens of billions devices - computers, smartphones, tablets, and sensors - connected to the Internet by 2020. This number will continue to grow at a rapid pace for the next several decades. With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo, June 9-11, 2015, at the Javits Center in New York City. Learn what is going on, contribute to the discussions, and ensure that your enter...
May. 25, 2015 01:15 PM EDT Reads: 2,475
In a recent research, analyst firm IDC found that the average cost of a critical application failure is $500,000 to $1 million per hour and the average total cost of unplanned application downtime is $1.25 billion to $2.5 billion per year for Fortune 1000 companies. In addition to the findings on the cost of the downtime, the research also highlighted best practices for development, testing, application support, infrastructure, and operations teams.
May. 25, 2015 01:00 PM EDT Reads: 1,502