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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As the data logger is wearable and it is generally worn at one side of the belly, the distance between a swallowed capsule and data logger will be near 0.
To get the best compression loxsless, the difference of luminance dY is encoded in Golomb-Rice code and the difference of chrominance dE and dF are encoded in unary for WLI images. Pseudo-color NBI images are reconstructed by combining two grayscale images in the computer software. Parameters for reconstructing NBI images can be set by the user in compressiob decoder module.
The overall block diagram of the capsule is shown in Figure 8. As a result, the entire compression system does not incur any loss of image information.
The synthesis results of the proposed lossless compressor are summarized in Table 8.
The YEF color space can be made fully reversible i. The received images are clear and lossless with details of the mucosa surface of the pig intestine. After color space conversion, the compressor takes the difference of consecutive pixels using differential pulse coded modulation DPCM and then encodes the differences in variable length Golomb-Rice [ 6 ] and unary coding.
In auto acknowledge mode, after receiving a data packet, the receiver checks the CRC bits and detects whether there was any error during the transmission of the packet. Swallowable medical devices for diagnosis and surgery: The data logger stores the image data and also shows reconstructed image on LCD.
As the comprsssion compression algorithm is lossless, the reconstructed image is identical to the original image. Comparison of compressor with other works. Compression assessment based on medical image quality concepts using computer-generated test images.
An improved lossless image compression algorithm LOCO-R
The lossy imate found in literature are mainly based on transform coding where the Discrete Cosine Transform DCT is used [ 8 — 15 ]. Ex-Vivo Testing In this experiment, comlression capsule prototype is inserted inside a section of pig’s small intestine; the data logger is placed outside. It is noted here that, medical implantable communication service MICS compatible RF transceivers that work at — MHz frequency, are the most suitable choice for transmitting data through human body [ 28 ].
During the experiment, the distance between the capsule and the data logger is varied from 0. The works in [ 8 — 10121315 ] are lossy compressors; these algorithms produces distortions in the reconstructed images which may lead to inaccurate diagnostics. The differential values of luminance component are encoded in Golomb-Rice code [ 6 ] where the differential values of chrominance components imge encoded in unary code.
So, the compressor should be able to accept input pixels loc-r in raster scan fashion which will make it compatible with commercial image sensors. This process goes on until the packet is transmitted successfully.
An improved lossless image compression algorithm LOCO-R – Semantic Scholar
However, the compressor in [ 24 ] is implemented in ASIC platform, which resulted in lower power consumption. Lossy image compressors produce some difference between the original and reconstructed images. Transmission power requirements for novel Zigbee implants in the gastrointestinal tract. So, in auto acknowledgement mode, generally no data loss happens.
Related Works Both lossy and lossless image compression algorithms are found in the literature targeting capsule endoscopy application. When Equations 2 — 4 are implemented in digital hardware as integers, minor variations in the pixel values may occur due to the rounding of fractions to integers. The different stages of the proposed algorithm as placed in the processing pipeline are briefly discussed below:.
Note that, the YEF color space does not discard the chrominance information; in fact, it is another representation of the RGB color space which is more suitable for compression and theoretically lossless.
As a result, the DPCM is a good choice. Pig’s intestine is chosen for experiment due to its relatively similar gastrointestinal functions in comparison to humans [ 33 ]. In capsule endoscopy, the corner areas in a captured image are often blacked out.
In order to validate the performance of the compression algorithm, it is deployed inside an endoscopic capsule prototype developed in our lab.