A Comprehensive Guide to Content Preparation with GeoBox
During visits to highly professional clients, we often encounter large images created by multiple projectors. These clients are eager to see how GeoBox can seamlessly perform geometric alignment and blending. However, the true magic of GeoBox begins with Content preparation. Unlike software based solutions, we have simplified this process. GeoBox has made the workflow more efficient and implemented a reliable video control mechanism that can operate 24/7. In the weapon system, they coined a term “fire and forget”, which aptly describes how GeoBox functions in every project.
But what does it mean when we say that GeoBox can simplify and streamline your workflow?
Understanding GeoBox's Hardware-Centric Design for Content Display
Hardware-based solutions depend on physical components like processors, circuits, and devices to carry out tasks. In contrast, software-based solutions use programming code and algorithms to utilize the “computational” resources supplied by hardware. Hardware-based solutions excel in performance and specific task optimization. Referring for proAV applications, we are talking about reliable 24/7 operation as long as power is available.
GeoBox, with its focus on hardware design, is compatible with any playback device. This includes laptops, DVD/Blu-ray players, media players, PCs, and game consoles…etc. By utilizing the GeoBox video controller, you can project single or multiple pieces of content from any source device across multiple projectors, and the content preparation is extreamly easy.
Grab a coffee, and let’s get started: Where will this article take you?
Suppose you’re considering GeoBox for your current or upcoming project. The first challenge you may encounter is: How should I preparing the content for a seamless and appealing display on a large wall?
In this article, we are going to explain the key factors that need to be considered when preparing contents:
Aspect ratio, Resolution, Pixel pitch, and Choosing proper Playback device.
Then, we prepared two case studies to better explain the concept:
Case 1: Bosch UK product launch event
Case 2: The Immersive SPA Room at Ragdale Hotel – Surrounding Wall Part
A step-by-step guide for content preparation
Just like all successful technical solutions, the underlying technology may be complex, but its usage should be intuitive and practical. In summary, we provide a three-step guide to help you prepare the content before starting the hardware installation.
Step 1. Determine the content "Aspect Ratio"
Before delving into content creation, it’s crucial to understand the importance of maintaining the original aspect ratio to prevent distortion when displayed. Imagine your target area measures 10 meters in width and 2 meters in height. To maintain fidelity, the content must align with this aspect ratio, such as creating content at 10:2 aspect ratio, equivalent to 5000 pixels x 1000 pixels or 10000 pixels x 2000 pixels.
Step 2. Determine the "Resolution"
After defining the aspect ratio, it’s essential to determine the optimal signal resolution. This process involves calculating the “combined resolution” of all the projectors, taking into account the “overlap of pixels”.
In theory, the optimal signal resolution can be calculated by summing the resolutions of all projectors and subtracting the pixels in the overlap area. For instance, if you have three 1920×1200 projectors arranged horizontally with a 20% overlap, the optimal resolution would be 4992×1200 pixels. The calculation is: (1920 x 3) – (1920 x 0.2 x 2) = 4992.
Wait… why the image ratio does not match the wall!
The content has been created with a 21:9 aspect ratio to fit the display area, but the projector use a 16:9 or 16:10 aspect ratio. As a proAV professional, you’re likely familiar with the initial projection image not fitting the display area. Furthermore, it’s also common for the source resolution to not match the aspect ratio of the display area, because the playback device might only output standard resolutions. This is very common with most media players.
GeoBox offers a simple solution to this problem. Its basic yet powerful geometric alignment feature allows you to reshape each image to fit the aspect ratio of the target display area. When GeoBox is set to the selectabale “Full screen” mode, the content fills up the entire output image. Thus, as long as the content is created in the same aspect ratio as the combined display area, there will be no distortion in the final combined image, regardless of the source resolution.
Image Clarity: It's all about Pixel Pitch
Knowing the ideal resolution for your content is helpful, but it’s not always achievable. What’s more important is figuring out the resolution you truly need. This depends on how clear you want your images to be, which relates to the viewing distance and pixel pitch.
Pixel pitch is determined by dividing the size of the image by the system resolution. The closer people are to the screen, the smaller the pixel pitch should be. A simple rule suggests that if people are X meters away, each pixel should ideally be X millimeters wide. For example, if people are 5 meters away and the image is 20 meters wide, a pixel pitch of 5mm is required, indicating a necessary resolution of 4K. Additionally, when discussing resolution, it’s not limited to projectors or source devices. It encompasses the entire setup, including content sources, controllers, transmission elements such as cables and connectors, all the way to the projectors themselves.
Step 3. Choosing "Content Playback Device"
While GeoBox allows the use of any playback device, selecting the right one is crucial for a smooth workflow and seamless content delivery, enhancing the viewer experience. Consider the following factors when making your choice:
- Complexity of your content: Does it involve 3D content, touch interactivity, or require high resolution?
- Versatility: Do you need to handle various types of content, such as videos, slideshows, presentations, or online streams?
- Plug-and-play: Do you prefer a dedicated and pre-configured content playback device that doesn’t require complex setup?
By carefully considering these factors, you can select the most suitable playback device that aligns with your specific content requirements and installation preferences. Three main options for playback devices – laptop, desktop PC, and media player – each have their strengths and weaknesses. If you want a dedicated device with plug-and-play functionality, a media player (BrightSign, for example) is an ideal choice. If flexibility is crucial, a laptop would be the most suitable. If performance and complex content handling are important, a desktop PC may be the better option.
Tip: Integrate and switch between multiple sources
GeoBox’s ability to support nearly any playback device is extremely useful when you need to utilize the same display area for various tasks. Typically, you might use a media player for video playback and a laptop for PowerPoint presentations. GeoBox offers exceptional flexibility by enabling seamless source switching or simultaneous playback from multiple sources.
Here’s a practical example from higher education in the Netherlands to illustrate how this works:
Creating large projection in School Theater for multiple purposes (Netherlands)
Case studies
Understanding the process is best achieved through examples. We’ve prepared the following example to better explain the concept:
Case 1: 125 years Bosch in UK, Immersive experience room
Project requirements:
Need to project one content across three walls (width: 4.5m-7.98m-4.5m, height: 2.7m) using four projectors. The longer middle wall is projected by two projectors, and the walls on each side are each projected by one projector.
Configuration diagram
- Decide content aspect ratio: To avoid image distortion, the playback content was prepared to match the final combined image’s aspect ratio, that is (4.8+7.98+4.8) : 2.7 = 17.58 : 2.7 = 6.5:1.
- Decide source resolution: We used four FHD (1920×1080) resolution projectors. The wall in the middle has a 20% overlap area. The optimal horizontal resolution is 1920×4 – 1920x 0.2 = 7,296 pixels. Given a viewing distance of around 3 meters, the pixel pitch can’t be larger than 3mm. As the total width of the three walls is 17.58m, the necessary system resolution is 5,860 pixels horizontally (17580mm/3mm).
- Select proper playback device and arrange content for it: The client preferred to use a dedicated content playback device, so BrightSign media player was used in this project. In order to reach the necessary system resolution, the content was cropped into two sources. The middle area content with the dimension of 7.98×2.7 was converted into Source A in the reoslution of 3840×2160@60hz. The rest of two contents for the side walls were in the dimension of 4.5×2.7 each, and were combined into Source B in the resolution of 3840×2160@60hz. Each of these 4K sources was fed into the two inputs of the G804. The G804 was then used to crop the content from source A for projector 2 & 3 with overlapping area in the middle, and to crop the content from source B for projector 1 & 4. The G804 also controlled the geometric alignment for all projectors and edge blending for projector 2&3.
Case 2: The Immersive SPA Room at Ragdale Hotel - Surrounding Wall Part
Project requirements:
Needed to project on 7 walls with 7 HD projectors to create a fully immersive experience in a SPA room. Active projecting area of each wall is in the dimension of 1.65m x 1m, and 16cm width gap between each two walls.
Configuration diagram
- Decide content aspect ratio: To avoid image distortion, the playback content is prepared in the same aspect ratio as the final combined image. In this instance, the content image is created in (1.65×7+0.16×6) :1 = 12.44:1.
- Decide source resolution: This case uses seven Full HD (1920×1080) resolution projectors. The optimal horizontal pixel count is 1920×7 = 13,440. The optimal resolution is 13,440×1080. Given that the viewing distance is around 1 meter, the pixel pitch cannot exceed 1mm. This means the necessary system resolution needs to be 13,440 pixels horizontally.
- Select proper playback device and arrange content for it: In order to reach the necessary resolution of 13440×1080, we used a PC capable of outputting two 7680×1080 signals.
The content was arranged in two 8K*1K signals. The first source (GPU output 1) was created from an 7680×1080 content transformed into a 8K/1K source. The second source (GPU output 2) was created from 5760×1080 content with 1920×1080 black content transformed into another 8K/1k source. Each of these 8K sources go to the two inputs of G408. The G408 is then used to divide the first 8K image into four pieces and output them to projectors 1 to 4. Similarly, the second 8K image is also divided into four pieces and output them to projectors 5 to 7. Given that there are gaps among the projectors, the G408 also allowed us to adjust the edge of each projected image using the overlap adjustment function.
Related articles:
The Synergy of Using BrightSign Player with GeoBox video Controller
How to display a large image using multiple projectors?
Edge blending calculator for multi-projector project planning
125 years BOSCH in the UK: Powered by GeoBox and Panasonic
Immersive Fusion: The Technological Creativities of Ragdale Hall Spa’s Thought Zone
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