An image interpolator with image improvement for LCD controller

First International Conference on Innovative Computing, Information and Control - Volume I (ICICIC'06)

In this paper, an adaptive interpolation algorithm is presented based on the Newton Polynomial to improve the limitation of the traditional algorithm for image resizing. The second-order difference of adjacent pixels gray values shows the relativity among the pixels. Accordingly, the adaptive function for image interpolation is deduced according to both this relativity and the classical Newton polynomial. Then the efficiency of our method is compared with that of the traditional algorithm for image resizing in Matlab. Furthermore, the implementation circuit architecture is devised by three stage paralleling pipelines for the adaptive image resizing algorithm and is verified in FPGA (field programmable gate array). The experimental results show that our proposed algorithm excels the bicubic interpolation in visual effect, and has a lower complexity. Therefore, the algorithm adapts to real-time image resizing.

IEEE Journal of Selected Topics in Signal Processing, 2000

2010 IEEE International Conference on Imaging Systems and Techniques, 2010

The color filter array (CFA) is a cost-effective structure widely adopted in modern digital still cameras (DSC). Because some color information has been filtered out, interpolation process is required to retrieve the original image. In literature, bilinear interpolation is commonly used due to its simplicity. No cross-channel computations are necessary in bilinear interpolation. By taking into consideration of interchannel correlation, Pei and Lam improved the bilinear interpolation without increasing much of computational complexity. Both approaches however suffer certain edge-aliasing effect by reason of their average (or lowpass) nature. In order to eliminate such edge-aliasing, a new interpolation method is proposed in this work. By excluding extreme neighbor pixels before the average operation, the edge can now be better preserved. Experiment results show that the proposed interpolation method not only preserves the object edges visually but generally gives smaller mean-square errors.

IEICE Transactions on Electronics, 2005

The pulsed backlight system has been introduced for reducing motion blurs of LCDs in high motion pictures. But applying the pulsed backlight, full screen flicker and inconsistency of transmissivity for entire frame at a lightening time should be considered. This paper discusses the analysis of blurs in high motion pictures and proposes the design method for more suitable display terminal of LCDs.

Human vision is more sensitive to find difference in the image rather than finding similarity. So, we are faster at identifying difference in the image. When we increases the contrast in an image, the difference between its intensity values increases, which gives a better visual stimulus to the eye. A colored image contains three or more values depending on the color model used. For example there are 3 values in the RGB, HSV and LAB. The RGB model are used for display purposes only and HSV/LAB are used for the image enhancement purposes. The contrast enhancement can’t be directly applied to the RGB values as it will change the color of the image, resulting to the color distortion. So, the RGB image is converted to the color model in which the parameter value have pixel intensity information or the model which separates the color information from intensity information. For example V in HSV and L in LAB contains the intensity information of the image. The contrast enhancement can now applied to intensity information of the image. Can be done in Contrast Enhancement can be done in spatial domain or in the frequency domain. In spatial domain the pixel values are directly modified, which is easier for implementation. The preferred method in the report are (a) Histogram Equalization: the image will have almost equal numbers of pixel on each intensity level and occupy full range of intensity level (0-255 in 8 bit image). (b) Cubic Spline Interpolation: the pixel intensity transformation function will be found out by using the interpolation of user defined data points. The method used is cubic equation spline interpolation.

A high dynamic range liquid crystal display (HDR-LCD) can much enhance the contrast ratio of images upon the locally controlled backlight. A novel method, inverse of mapping function (IMF), was demonstrated to further improve the HDR image quality from the information of each frame. By using IMF, the contrast ratio of image in a 37" HDR-LCD TV was successfully improved to ~20,000:1 with high brightness and clear image details. Besides, for mass production, the backlight of the 37" HDR-LCD TV was divide into 8×8 zones to lower the cost and hardware computation complexity.

IEEE Transactions on Consumer Electronics, 2008

In this paper, we propose a fine edgepreserving image interpolation algorithm based on local gradient features. The proposed algorithm determines the edge direction using horizontal and vertical gradient operators, and then the edge direction is conceptually changed to the position between adjacent pixels. Since our algorithm is independent of interpolation kernels, various conventional kernels can be implemented. Experimental results show that the proposed methods can preserve clear edges and reduce blurring artifacts 1 .

SID Symposium Digest of Technical Papers, 2000

This paper describes the filtering used in Microsoft ClearType. ClearType is a software system than enhances the resolution and readability of fonts on displays that contain a repeating pattern of addressable colored sub-pixels. The filtering in ClearType is based on a perceptual model of human vision. The perceptual model leads to an optimization technique for finding the best output values. The results of the optimization can be approximated by pre-filtering each color channel of an input image and then sampling each filtered color image at the spatial locations of the same colored sub-pixels in the display. We refer to this filtering followed by displaced sampling as RGB decimation. RGB decimation eliminates the phase error caused by standard anti-aliasing. A further approximation of the optimal filter yields RGB decimation with displaced box filters. Fourier analysis demonstrates that both the optimization technique and the displaced box filter suppress frequencies that contribute most to color fringing in unfiltered displaced sampling.

IEEE Transactions on Consumer Electronics, 2008

Some factors of the environment and user behavior always dominate the captured image quality when we use a digital camera. According to the overviews and analysis of adaptive brightness correction, we understand that techniques can provide an available method to reduce the interference of environmental light in digital cameras, but current methods are still not suitable for VLSI design. In this paper, we propose an efficient method, called local bi-histogram equalization (LBHE), to remedy the local visibility and control the degree of enhancement. In architecture design, we utilize the hybrid architecture to implement adaptive brightness correction with the MPEG system. The hybrid architecture design can decrease the implementation area and successfully applies our LBHE in MPEG application. Through comparison of content, we can find that our design can exactly satisfy the chip specification of realtime processing. Our chip implementation is efficient to achieve motion and brightness estimation in the MPEG system. This design makes adaptive brightness correction compatible to current video applications.

Multimedia Tools and Applications, 2019

In this paper, hybrid models for image quality enhancement are presented comprising both Contrast Limited Adaptive Histogram Equalization (CLAHE) and image interpolation. Adaptive histogram equalization is employed for contrast enhancement, while image interpolation is employed for resolution enhancement. Both the CLAHE and image interpolation are used interchangeably to check the most suitable model for quality enhancement of Low-Resolution (LR) images. The utilized interpolation techniques throughout this paper are polynomial and inverse techniques. Simulation results prove that the application of the CLAHE after interpolation gives the best image quality, especially with regularized inverse interpolation.