which should have higher entropy?

Started by Todd in comp.dsp12 years ago

I made a similar post sci.image.processing a while back. I'm trying to understand why a my natural images are higher entropy than...

I made a similar post sci.image.processing a while back. I'm trying to understand why a my natural images are higher entropy than uniform noise. The order from lowest to highest is constant (0 obviously), uniform noise, LPF'd image, same image not LPF'd, gaussian noise My theoretical calculation for uniform noise agrees with what I'm getting -- about 1/256*log2(256)*241^2. Now there a...


how to convert image in to binary bits sequence

Started by ahali in comp.dsp13 years ago 7 replies

i m doing a project in image watermarking .any of you guys know that how to convert image in to binary bits sequence . i have tried this...

i m doing a project in image watermarking .any of you guys know that how to convert image in to binary bits sequence . i have tried this simple code , a=imread('lena.jpg'); b= round(a./256) but i got binary bits like this= column 1 to some columns 1 0 1 0 0 1 0 0 0 0 0 0 0 1 0 1 0 1 0 0 . . . 1 0 0 0 0 0 0 0 0 ...


why is an image non-stationary?

Started by kiki in comp.dsp16 years ago 10 replies

Hi all, I am not sure I completely understood... but I've heard people say that an image is non-stationary, blah blah blah, what does...

Hi all, I am not sure I completely understood... but I've heard people say that an image is non-stationary, blah blah blah, what does that mean? and what does that imply? I vaguely heard that people say since an image is not-stationary, so Fourier Transform should not be applied, etc... Can anybody throw some lights to me? thanks a lot!


Image spatial frequency resolution

Started by Chris Bore in comp.dsp15 years ago 10 replies

Image 'spatial frequency resolution' seems to be used to mean: - the highest spatial frequency that can be resolved. Experimentally, an image...

Image 'spatial frequency resolution' seems to be used to mean: - the highest spatial frequency that can be resolved. Experimentally, an image of sinusoidal intensity is displayed and the contrast varied until the viewer can see the bar pattern. This is using 'spatial frequency resolution' to measure our ability to resolve adjacent light and dark features. I am interested in spatial freq...


what's the key properties of DCT/IDCT that lend it such wide use in image processing?

Started by walala in comp.dsp17 years ago 8 replies

Dear all, Can anybody tell me what are the key properties of DCT/IDCT(2D) which lend it to the such wide use in image processing? I mean,...

Dear all, Can anybody tell me what are the key properties of DCT/IDCT(2D) which lend it to the such wide use in image processing? I mean, why FFT, DHT, and other transformations are not used in image processing/compression? Book says that DCT resembles K-L transformation mostly, but how about the other transforms? Anybody give me some explanations? Thanks a lot, -Walala


need advice on image filter?

Started by lucy in comp.dsp16 years ago 14 replies

Hi all, We used camera to do some imaging and got some raw image data, which are very noisy at the low signal end(where there should be some...

Hi all, We used camera to do some imaging and got some raw image data, which are very noisy at the low signal end(where there should be some low signal) or the dark end(where there should be no signal theoratically)... And there are some some spikes on both dark and bright regions. The bright parts of the image are also noisy... Please advise which type of filter can be best for den...


how to compare the two image objects with different size?

Started by lucy in comp.dsp15 years ago 2 replies

Hi all, I want to compare two image objects... they look very similar to human visual system... but I want to find their similarities by...

Hi all, I want to compare two image objects... they look very similar to human visual system... but I want to find their similarities by metrics... The two image objects are embedded in two different large images... I mean, they are surrounded by dark or near-dark background in two larger images... And these two larger images are of different sizes and different sampling rate... And...


reconstructing image

Started by khalloud70 in comp.dsp12 years ago 8 replies

I have image 256*256 , i compressed it using the Block Processing 'block' to be 128*128, and i want to encode it by reed solomon . so i export...

I have image 256*256 , i compressed it using the Block Processing 'block' to be 128*128, and i want to encode it by reed solomon . so i export it to the workspace using yout block and encode it by rsenc as follows: p=gf(yout,8) code=rsenc(p,138,128) d=rsdec(code,138,128) and this works fine but i want now to reconstruct the image after it had been decoded as variables , d and code are o...


Need Image analysis/koding tools

Started by Nimo in comp.dsp11 years ago 9 replies

Hi..folks..; Currenlty, I'm handling some stuff on Lossy algo's (for Images). where can I find image *analysis* tools to check the...

Hi..folks..; Currenlty, I'm handling some stuff on Lossy algo's (for Images). where can I find image *analysis* tools to check the results, I mean to see these stuff side by side for the testing image(s)., like (a) RMSE, (b) PSNR, (c) Histograms, (d) Spectral analysis, (e) Handling color spaces, (f) dithering stuff etc..etc..., I hope you people know it better than me; ...


EPPI Sychronization problem on BF548 EZ-kit

Started by hbd730 in comp.dsp11 years ago 3 replies

Hi all, I am doing a video project,using BF548EZ-Kit and OV7620 image sensor. The sensor is connected directly to the borad via EPPI1...

Hi all, I am doing a video project,using BF548EZ-Kit and OV7620 image sensor. The sensor is connected directly to the borad via EPPI1 interface. For testing, a single frame can be captured after setting up the DMA13 and EPPI1 configuration. I use image viewer to display a image with a start address that I specified in the DMA start address. The problem is every time I got a frame, it seems ...


Image Processing Event at IIT Kharagpur

Started by Anonymous in comp.dsp13 years ago

http://www.robotix.in/ Hello People The Robotix Team of IIT Kharagpur has shifted to its new site. A new design, new problem...

http://www.robotix.in/ Hello People The Robotix Team of IIT Kharagpur has shifted to its new site. A new design, new problem statements. Please visit www.robotix.in for details. The Image Processing event can be reached at http://www.robotix.in/image.php


what is hyperspectral image?

Started by gino in comp.dsp16 years ago 10 replies

Dear folks, I have heard of a lot buzz about "hyperspectral" image... I did some googling and did find some researches on this, but I am still...

Dear folks, I have heard of a lot buzz about "hyperspectral" image... I did some googling and did find some researches on this, but I am still not able to figure out what's it and what's the use of it... Anybody gives me some pointers? Thanks a lot, -Gino


imresize in 3D

Started by Sylvia in comp.dsp11 years ago 4 replies

Hello, I want to resize an image from 3D smaller dimension to larger dimension. i.e for example from 40x40x30 to 40x120x90. The normal matlab...

Hello, I want to resize an image from 3D smaller dimension to larger dimension. i.e for example from 40x40x30 to 40x120x90. The normal matlab function just resizes image in 2D. Thanks


Idea exploration 1.1 - Inertia based angular sensor.

Started by Kris Neot in comp.dsp15 years ago 5 replies

This idea is used to serve my old idea of "Image stabilization by means of software.". I was aware that it was difficult to find angular sensor...

This idea is used to serve my old idea of "Image stabilization by means of software.". I was aware that it was difficult to find angular sensor that can run at 1MS/s. I will have a cubic enclosure, two perpendicular walls are made of small/fast image sensors. I use a hanging ball and a laser to shine upon it. The image sensors will detect the exact location of the ball (hopefully 1000 time...


inversie filtering?

Started by walala in comp.dsp17 years ago 3 replies

Dear all, I have an image and had been processed by a certain filter(I sort of can guess the filter out) how can I inverse that process and...

Dear all, I have an image and had been processed by a certain filter(I sort of can guess the filter out) how can I inverse that process and restore the original image? Thanks a lot, Michael.


what are the training algorithm you guys are using for adpative filtering for image processing?

Started by walala in comp.dsp17 years ago 4 replies

Dear all, I have a question about adaptive filtering for image enhancement. I want to design an algorithm for image enchancement. It should...

Dear all, I have a question about adaptive filtering for image enhancement. I want to design an algorithm for image enchancement. It should work on most of images. So I need to make it adaptive. I guess what I need is to extract some features from different images. I did extract the largest eigenvalue of the covariance matrix of the input images. I use this eigenvalue as "x". Then I...


image out-of-focus blur identification

Started by Ling Chen in comp.dsp8 years ago 47 replies

Hi there, Suppose an image is out-of-focus blurred. We have the original image and its blurred version. What is the best approach to estimate...

Hi there, Suppose an image is out-of-focus blurred. We have the original image and its blurred version. What is the best approach to estimate the blur function? That is, given y(m), x(m), how to we estimate the point spread function (or impulse response function) h(m): y(m) = h(m)*x(m) + n(m) where n(m) is some kind of background noise. We are expecting to use some kind of minimized...


How to recognize the signal?

Started by LVitya in comp.dsp7 years ago 14 replies

I have a signal from sensor. It look like upper part of this...

I have a signal from sensor. It look like upper part of this pictures http://postimg.org/image/l51neenup/ http://postimg.org/image/ddkxfujpd/ I need to recognize two oposite forms of signal: 1) when it goes up then down; 2) when it goes down then up. For example http://postimg.org/image/vxuhwk611/ On this picture 1st forms are marked, 2nd is unmarked. I tried to use cross-correlation (xc...


Image processing systems

Started by Gary Ford in comp.dsp16 years ago 2 replies

I need a image processing system to perform various autonomous machine vision applications. A PC (or Laptop) is one alternative but I...

I need a image processing system to perform various autonomous machine vision applications. A PC (or Laptop) is one alternative but I was wondering what else is available. As it's a research project cost is an issue.


Can CCD camera output more than just intensity information of image?

Started by walala in comp.dsp16 years ago 8 replies

Dear all, I am curious about how CCD works to pick up images... more specifically, I wonder CCD camera can output more than just pixel...

Dear all, I am curious about how CCD works to pick up images... more specifically, I wonder CCD camera can output more than just pixel intensity information of an image? For example, I want to know the "variation" property of a block of an image, for example, a 8x8 block... roughly classified into "smooth" block and "non-smooth" block, two classes... I want to know if CCD can judge this ...