LOCO-I (LOw COmplexity LOssless COmpression for Images) is the algorithm at the results at the time (at the cost of high complexity), it could be argued that the improvement .. In the sequel, we assume that this term is tuned to cancel R. LOCO-I (LOw COmplexity LOssless COmpression for Images) is the . Faria, A method to improve HEVC lossless coding of volumetric medical images, Image . A. Lopes, R. d’Amore, A tolerant JPEG-LS image compressor foreseeing COTS. Liu Zheng-lin, Qian Ying2, Yang Li-ying, Bo Yu, Li Hui (), “An Improved Lossless Image Compression Algorithm LOCO-R”, International Conference On.

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To make the hardware modular, the capsule is divided into four boards: However, this unit is not offered for public purchase; instead they offer a low data-rate transceiver part ZL with data rate of kpbs [ 26 ] which is not even sufficient for 2 frames per sec application.

This zn can be noticed from Table 2.

An improved lossless image compression algorithm LOCO-R – Semantic Scholar

Photograph of the capsule prototype size compared with a The CR of the images in the real experiments is similar to the results found during simulation. In order to save wireless transmission power and bandwidth, an image compressor needs to be implemented inside an endoscopy capsule. Intensity distribution of color components of an NBI image: The performance of the compressor has been validated using a miniature FPGA based capsule prototype and by performing ex-vivo and in-vivo trials with pig’s intestine and live pig respectively.

The works in [ 518 ] by our group present lossy compression algorithms which do not require block based access of image pixels; rather they can work with pixels coming in raster scan fashion.

Due to the mismatch of pixel steaming sequence of commercial image sensors and pixel lossess sequence required by transform based compression algorithms, buffer memory needs to be implemented inside the capsule to store a complete or blocks of an image frame, so that the image pixels can be accessed by the compressor in block wise fashion from the buffer memory. The motivation for the YEF color space comes comression the fact that, endoscopic images generally exhibit dominance in red color with the absence of significant green and blue components.


It has low computational complexity and can be directly interfaced with commercial image sensors.

An improved lossless image compression algorithm LOCO-R

As the compressor is lossless, compressionn produces reconstructed images without any distortion and thereby reduces the possibility for inaccurate diagnostics. However, in hospitals in these days where Picture Archiving and Communication Systems PACS are used to store medical and diagnostic data in digital form, lossless compression is a requirement [ 4 ]. The synthesis results of the proposed lossless compressor are summarized imaye Table 8.

Variable Length Coding The difference of the consecutive pixels dX is then mapped to a non-negative integer and then they are encoded in variable length coding.

In this experiment, the capsule prototype is inserted inside a section of pig’s small intestine; the data logger is placed outside. Fast compression algorithms for capsule endoscope images. Khan [ 20 ]. From Equations 2 — 4it is observed that the conversion between color spaces involves only a few additions and divisions by numbers that are powers of 2, which can be implemented by shift operations in digital hardware. Pseudo-color NBI images are reconstructed by combining two grayscale images in the computer software.

The CE prototype is then tested to assess the performance using live pig in both ex-vivo and slgorithm trials at the animal facility. So, in auto acknowledgement improver, generally no data loss happens. An ultra-low-power image compressor for capsule endoscope. All these components are fully optimized for low-cost operation and lossless in nature; as a result, no loss of any diagnostic information takes place inside the endoscopic system. A detailed discussion on choosing k parameter can be found in Section 3.

Wahid [ 8 ]. Images from different positions of GI tract. Block diagram of the proposed lossless compression algorithm. The k parameter values are summarized in Table 3.

However, this solution can create timing error if compression and transmission time exceeds the input data rate of the image sensor. Compression ratio of the proposed algorithm for WLI images. Captured lossless WLI images from pig’s intestine: Both lossy and lossless image compression algorithms are found in the literature targeting capsule endoscopy application.

Parameters for reconstructing NBI images can be set by the user in the decoder module. Imafe video capsule enteroscopy in preclinical studies: In order to compare the proposed YEF color space for endoscopic images with the conventional YCoCg color space, we have conducted additional simulations by replacing the YEF color space by YCoCg in the proposed compression algorithm.


Then an optional clipping module is added improvev removes uninteresting corner area of the image.

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K parameter for encoding component differences. However, commercially available complementary metal-oxide-semiconductor CMOS image sensors [ 1617 ] send pixels in raster scan fashion i. In Table 9the proposed compressor is compared with similar other works. This article has been cited by other articles in PMC.

In this paper, a low complexity yet lossless image compression algorithm is presented that is purposely designed for capsule endoscopy. When comparing with JPEG-LS, the proposed algorithm has higher compression ratio, lower computational complexity such as static prediction and static k parameter and lower memory requirement.

A safer solution of this problem could be to use sufficient memory to store a complete image frame. Transmission power requirements for novel Zigbee implants in the gastrointestinal tract.

Moreover, the algorithms presented in these works are based on DCT which has computational complexity of O n log n and need buffer memory as described earlier. In [ 20 ], our group proposed a lossless image compressor based on YUV color space.

For medical diagnostics, the distortion of the reconstructed image can lead to inaccurate diagnostics decisions, though in medical and endoscopic imaging, lossy compression is acceptable up to a certain point for example, a compression ratio of 15 was found as the visually lossless threshold for the JPEG lossy algorithm [ 3 ]. Compression with other compression algorithms. Bothe the in-vivo and ex-vivo experiments indicate the effectiveness of the proposed lossless compression algorithm.

It may generate very small variations in pixel values at the output stream which is visually unnoticeable to human eyes when displayed as an image. Experiments have been conducted to show a bit error rate BER of less than 0. Comparison with Other Prototype Works In Table 9the proposed compressor is compared with similar other works.

The results show that, compared with all other existing works, the proposed algorithm offers a solution to wireless capsule endoscopy with lossless and yet acceptable level of compression.