FAQ - hipix™
Q. What is hipix™ compression?
hipix™ compression is a still- image compression algorithm, developed and patented by "Human – Monitoring", which is based on the widely used, from handsets to Blu-Ray DVD and HD TV, h.264 video compression codec, designed to yield a compression performance that significantly out performs JPEG compression algorithm.
Q. How much better is hipix compared to JPEG?
Depending on the content and the resolution, it typically yields a compression gain of about 2 to 5 times better than the JPEG.
Q. Does the fact that it is based on h.264 compression code for still-image, mean that it just uses the h.264 intra-prediction scheme for the compression?
No. in most case, the hipix™ algorithm actually uses both the h.264 inter and intra prediction schemes, which give much higher compression gain over the intra-only coding.
Q. How is it possible to use inter-prediction scheme, which is a video motion feature, in still image compression?
Well, this is the core idea of the hipix™ algorithm, in which the image is partitioned into a sequence of tiles, all are highly correlated to each other, this sequence is then treated as a formal group of video pictures, GOP, complying with the syntax of h.264 intra-inter prediction definition. This GOP is encoded by a standard h.264 encoder – where the first tile is treated as an “I frame” and compressed using intra-prediction, while the rest of the sequence is treated as “P” or “B frames”. Since the difference between the highly correlated tiles is small, the coding of the “P” and “B frames” consume less bits than the “I frame”.
Q. How can you produce, out of a given single frame, a series of highly correlated tiles?
This can be accomplished by extending the well known idea of interlacing into a higher dimensions level. The hipix™ algorithm utilizes a unique algorithm termed "Similarity Partitioning Algorithm”, which performs this task.
Q. In the few cases where hipix uses one tile feature – intra coding, does it still bear any advantage over the standard h.264 intra-coding.
Yes, even in that case, the hipix coder has significant advantage over the standard h.264 intra coding scheme, due to a quantization strategy that is content-adaptive in nature. This technology fits within the h.264 standard and avoids applying a quantization level, which could cause block artifacts even when using rather high compression ratio.
Q. What is the significance of choosing h.264 as the "base platform" for hipix™?
As most handsets that are currently in use in the market are already equipped with h.264 built in HW accelerators, hipix™ can easily utilize those HW H.264 Codecs with no need for any HW changes.
Q. Is the technology limited to h.264?
No. hipix can be utilized using any intra-inter coding scheme, including MPEG 1/2/4, VP6/7/8, AVS etc. We preferred implementing our patent pending technology first using h.264 due to the wide HW infrastructure and market acceptance.