QuickLogic’s Visual Enhancement Engine (VEE™) Brings iridix® to Mobile Devices (WHITE PAPER)

Mobile Video Challenge

The iridix core dynamically calculates and applies a different tone curve to each pixel depending on content and position in the image. This pixel-by-pixel dynamic range and color correction enables far better control of contrast than traditional techniques. However, it also requires high CPU computing resources and, therefore, higher power consumption. Also, the iridix software must be optimized for different CPUs and DSPs. For example, in an ARM11 CPU the iridix software library processes 30 fps QVGA while consuming about 75% of the resources. The processor load scales linearly with pixel count and pixel clock rate.

With such a high CPU utilization requirement, it is very challenging to support a smooth and responsive user experience in a multi-tasking operating system. Users may experience slow transition from one application to another or see jerkiness in the video when another application with higher priority interrupts and slows the process down. Other features such as sharpening, dithering and color correction in addition to the iridix core further exacerbate the situation by putting more load on the power-hungry CPU. Even for processors that have a dedicated accelerator (such as the TI OMAP), it is estimated that the iridix core would consume most of the dedicated resources.