Given a simple image of size 10 × 10 whose histogram models the symbol probabilities and is given by The first order estimate of image entropy is maximum whenp1 p2 p3 p4 a b c d
a = \(\frac{1}{4}\), b = \(\frac{1}{4}\), c = \(\frac{1}{4}\), d = \(\frac{1}{4}\)
The first order entropy estimate uses the histogram probabilities directly: \(H = -\sum_k p_k \log_2 p_k\) bits/pixel (a term with \(p_k = 0\) contributes 0). The image size 10 × 10 does not affect it.
a = 0, b = 0, c = 0, d = 1: \(H = -1\log_2 1 = 0\) bits (no uncertainty at all).
Two symbols with \(\frac{1}{2}\) each: \(H = 2 \times \frac{1}{2}\log_2 2 = 1\) bit.
Three symbols with \(\frac{1}{3}\) each: \(H = \log_2 3 \approx 1.585\) bits.
Four symbols with \(\frac{1}{4}\) each: \(H = 4 \times \frac{1}{4}\log_2 4 = 2\) bits. This is the largest value; in general entropy of K symbols is maximum, \(\log_2 K\), when all are equally likely.
Hence, the answer is a = \(\frac{1}{4}\), b = \(\frac{1}{4}\), c = \(\frac{1}{4}\), d = \(\frac{1}{4}\).
A Butterworth lowpass filter of order n, with a cutoff frequency at distance D0 from the origin, has the transfer function H(u, v) given by
Given two spatial masks
\(S_1=\begin{bmatrix}0&1&0\\1&-4&1\\0&1&0\end{bmatrix}\) and \(S_2=\begin{bmatrix}1&1&1\\1&-8&1\\1&1&1\end{bmatrix}\)
The Laplacian of an image at all points (x, y) can be implemented by convolving the image with spatial mask. Which of the following can be used as the spatial mask ?
A technique used to approximate halftones without reducing spatial resolution is known as _________.
Blind image deconvolution is __________.
The redundancy in images stems from :
Given an image of size 1024 × 1024 pixels in which intensity of each pixel is an 8-bit quality. It requires _______ of storage space if the image is not compressed.
Which of the following is used for the boundary representation of an image object ?
A Butterworth lowpass filter of order n, with a cutoff frequency at distance D0 from the origin, has the transfer function H(u, v) given by
Given two spatial masks
\(S_1=\begin{bmatrix}0&1&0\\1&-4&1\\0&1&0\end{bmatrix}\) and \(S_2=\begin{bmatrix}1&1&1\\1&-8&1\\1&1&1\end{bmatrix}\)
The Laplacian of an image at all points (x, y) can be implemented by convolving the image with spatial mask. Which of the following can be used as the spatial mask ?
A technique used to approximate halftones without reducing spatial resolution is known as _________.
Blind image deconvolution is __________.