What to look for when choosing a Frame Grabber?

When you develop low-volume products, such as custom applications, the software engineering investment far outweighs the hardware cost. For such applications, there is little consequence to purchasing a frame grabber with extra features that might not be used in the final product design. When you develop a high-volume product, total engineering costs are spread over the number of units shipped, lessening their impact on per-unit profits.

Savings in hardware costs on each unit go directly to your company’s profits. The frame grabber is one of the most expensive single components in vision based products. So, making the appropriate choice requires finding a frame grabber that meets the product’s technical requirements at the minimum cost. Often this choice is left to the project engineer due to the technical issues involved. However, the major impact of this decision on product profitability means that understanding this technology can be very important to managers as well. There are 2 questions specifically need to be answers:

a) What features should you look for when choosing a frame grabber?
b) How can you use published specifications when evaluating frame grabbers?

Checklist for choosing a frame grabber

1. Low pixel jitter for precision digitizing accuracy: ±5ns or better.
2. Low gray-scale noise to eliminate false edges and handle low-contrast images: 0.7 LSB or less.
3. Gain and offset (±100%) controls to adjust for amplitude problems in the incoming signal.
4. Stable sync timing with the ability to re-synchronize to the first field of incoming video for working with resettable cameras and other variable signal sources: look for a crystal-controlled digital pixel clock.
5. Input lookup tables for pixel gray-scale translations for gamma correction or thresholding, and output lookup tables for false color.
6. For international applications: support for both NTSC, PAL, and SECAM video signals.
7. The right bus design for your application: STD or PC104 bus for embedded system designs; PCI bus for high-performance. Etc.
8. On-board memory for data transfer-intensive applications and applications where a high-performance bus isn’t available.
9. Single-monitor solution to minimize system cost.
10. Graphics overlay for adding annotations or alignment marks to an image.
11. Digital I/O for communicating with cameras and other devices: trigger, strobe, and any other required signals.
12. Power output for supplying a camera or other device without adding a separate power supply to the system.
13. Comprehensive software support: high-level programming languages, choice of operating systems, rapid application development tools, source code examples, and support for third-party libraries for image processing.
14. Complete, concise documentation on the hardware and software.
15. Responsive technical support via telephone, Internet, and email.
16. Reliability: low parts count, low power consumption and a strong reputation in the industry.

Reference
Choosing a frame grabber for performance & profitability
(Author: Gail Marshall)

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