- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Edge based enhancement of retinal images using an efficient JPEG-compressed domain technique
摘要： With substantial usage of Imaging Technology in the medical field for the diagnosis and treatment of illnesses, a huge volume of medical images are being generated which provide a bigger challenge in terms of storage, transmission and processing. The high resolution medical images thus generated occupy large storage space, and hence they are subjected to compression to make them storage and transmission efficient. Though compression overcomes the issues of storage and transmission to some extent, but the problem of processing compressed images still remains as a challenge. This is because; the usual way of processing the compressed medical images is through the operations of decompression and recompression, which consume lots of computing resources. Therefore, it would be novel, if the compressed medical images are processed and analysed directly in the compressed formats without involving the expensive operations like decompression and recompression. In this direction, the current research paper demonstrates a novel technique of edge based enhancement of retinal images, which is a very critical operation from disease diagnosis perspective, directly in the JPEG compressed domain. The developed algorithm is validated with publicly available retinal datasets of DRIVE and DIARETDB1, and the performance reported is compared with the state-of-the-art techniques in the uncompressed (spatial) domain in terms of both quality of enhancement and computation time.
关键词： compressed domain,Edge enhancement,Discrete Cosine Transform (DCT),JPEG compressed domain,retinal images
更新于2025-09-23 15:22:29
-
Orientation-selective edge enhancement of phase objects
摘要： We present a method for the orientation-selective enhancement of the first derivatives ?i.e. the edges? of a pure phase object. The proposed method is based on the transport-of-intensity equation (TIE). The TIE contains a term proportional to the scalar product of the phase gradient and an intensity gradient, which plays the role of amplifying factor of the first derivatives. We will show that if the intensity gradient is implemented in the optical setup as a moving amplitude mask with a relatively sharp border ?or eventually, a digital shifting mask displayed in a liquid crystal display? it is possible to generate a synthetic image of the phase object with enhanced edges. The proposed technique is potentially useful in biological and biomedical research. Validation experiments and preliminary qualitative results illustrating the generation of synthetic images with enhanced edges are presented.
关键词： Transport-of-intensity equation,TIE,Edge enhancement of pure phase objects
更新于2025-09-10 09:29:36
-
Infrared upconverted image edge enhancement using spiral phase filter
摘要： We present a theoretical and experimental demonstration of infrared upconverted image edge enhancement, acquired with quasi-phase-matching for the sum-frequency conversion process and a spiral phase filter. By illuminating a transmission mask with a 1559.5 nm Gaussian beam to create an infrared image and pumped with a 1064 nm vortex beam, an upconverted edge-enhanced image at 632.5 nm is generated. The theoretical model for the process is derived, which well explains the deviation of experimental results. The proposed technique can be further adapted for other spectral regions and nonlinear optical processes.
关键词： infrared upconverted image,spiral phase filter,edge enhancement
更新于2025-09-04 15:30:14
-
Two stage image de-noising by SVD on large scale heterogeneous anisotropic diffused image data
摘要： De-noising of images along with the edge enhancement has always been a challenging task in large scale heterogeneous image data. This paper presents a two stage image de-noising as well as edge enhancement method where in the first stage two copies of input noisy image are created through diffusion. The first copy is got by using anisotropic diffusion method which employ optimal diffusion function while the second copy is generated to improve the sharp edges by applying the combination of inverse heat diffusion and Canny edge detector. In the next stage, the singular value decomposition is applied on the two copies achieved in first stage to reduce the noise and improve the quality of detected edges. The optimal number of significant singular values have been estimated by the analysis of signal to noise ratio of singular value decomposed images of first copy. The singular values extracted from the second copy of the diffused image are superimposed with non decreasing weights from linear weighting function. Finally the sharp edged and noise reduced output image is generated by taking the linear combination of two singular value decomposed images. The performance of the proposed method has been compared with existing methods based on singular value decomposition as well as anisotropic diffusion. The experimental results exhibit that the proposed method efficiently enhances the edges by reducing the noisy significantly.
关键词： Image de-noising,Anisotropic diffusion,Edge enhancement,Singular value decomposition
更新于2025-09-04 15:30:14