## Forums Search for: Image

## image watermarking

inHi I'm looking to implement image watermarking using DM642. Is there any available algorithms out there that can be used for free? Let me...

Hi I'm looking to implement image watermarking using DM642. Is there any available algorithms out there that can be used for free? Let me know

## Correct way to implement Discrete and Stationary Wavelet Transform?

Can someone please confirm if this is indeed the correct way to compute DWT: load image load Haar wavelet for i = 1: Level periodize...

Can someone please confirm if this is indeed the correct way to compute DWT: load image load Haar wavelet for i = 1: Level periodize edges of image convolve image with Low pass Haar wavelet filter and store result in G convolve image with Low pass Haar wavelet filter and store result in H convolve G with low pass Haar to calculate approximation co-eff convolve G with high p...

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

inDear 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

## Low complexity approach of measuring signal/image local activity?

inDear all, I am facing with the following image/signal processing problem: In order to measure image local activity, I take variance....

Dear all, I am facing with the following image/signal processing problem: In order to measure image local activity, I take variance. But variance involves square operation, suppose I am working on NxN blocks, then the N^2 square will need a lot of computation, which is very costly in my current application. Is there any techniques of measuring local activity by way of lower complexity co...

## How to recognize the signal?

inI 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...

## what is hyperspectral image?

inDear 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

## Image Denoising and Wavelet Thresholding

inHello, I am currently doing a research on the above subject. I am not sure about the level of decomposition during wavelet transform. What is...

Hello, I am currently doing a research on the above subject. I am not sure about the level of decomposition during wavelet transform. What is the reasonable number of levels to decompose for image denoising? Thanks.

## LTI Image Interpretation

inHow would you interpretate this image about LTI systems and convolution?: [img]http://i.imgur.com/JAlHsYs.jpg[/img]

How would you interpretate this image about LTI systems and convolution?: [img]http://i.imgur.com/JAlHsYs.jpg[/img]

## Unmasked Vesta

The pictures shown in the following URL; http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=2017 are the original image of...

The pictures shown in the following URL; http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=2017 are the original image of Vesta (left), its de-convoluted image (middle / focus depth:=3.8, iteration:=8 / software: Focus Corrector ) and another de-convoluted image (right / focus depth:=4.3, iteration:=8 / software: Focus Corrector). For detail of Focus Corrector, visit...

## masking

inhi everyone, can u explain to me what is masking?and its function in image processing?its a new thing for me since ive never studied on...

hi everyone, can u explain to me what is masking?and its function in image processing?its a new thing for me since ive never studied on image processing before..would like to know more in detail..thnx ;)

## Image Processing Event at IIT Kharagpur

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

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

inDear 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 ...

## 2D FFT

inCould someone please explain the concept of 2D FFT in more layman terms? Most if not all the resources i read about 2D FT for image processing...

Could someone please explain the concept of 2D FFT in more layman terms? Most if not all the resources i read about 2D FT for image processing are loaded with lots of mathematical formulaes which I believe are important, but have problems understanding. I just want a basic conceptual idea about the technique before using some freeware to compute the 2D FT of a brain image. Thanks alot for your ...

## "Lena" or similar compression tests

inDoes anyone have source data for any standard image compression images such as "Lena" in integer/unsigned char format? If not - is there an...

Does anyone have source data for any standard image compression images such as "Lena" in integer/unsigned char format? If not - is there an easy way I can obtain this by opening an image in Matlab? Cheers Gary

## Search of a binary image from library

inHello! I prepared a library of 40 images. I want to create a search to find the best fitting image out of the 40 in the library to a new unknown...

Hello! I prepared a library of 40 images. I want to create a search to find the best fitting image out of the 40 in the library to a new unknown image. For now, I'm assuming all images are the same size and are binary. The search can, for instance, be between 40 binary matrixes to a new binary matrix or between 40 binary vectors to a new unknown binary vector. It's important for me to find an eff...

## Re: ANNOUNCEMENT: New image format

John Costella schrieb: > 12:30 pm CST, November 22, 2007 > > > I am pleased to announce the release of a new image format, which I > ...

John Costella schrieb: > 12:30 pm CST, November 22, 2007 > > > I am pleased to announce the release of a new image format, which I > have somewhat mischievously dubbed "JPEG-Clear", which is optimized > for the following uses, among others: Update to that: 1) Please add a Makefile. Here's one: CFLAGS = -Wall -pedantic -O3 CC = gcc LDFLAGS = -lm all:

## Image separation algorithm

inHi, I am looking for an algorithm that is use to separate a focused object from an image/video. I was thinking about edge detection algorithm...

Hi, I am looking for an algorithm that is use to separate a focused object from an image/video. I was thinking about edge detection algorithm but if the image/video contains a lot of information, I am not very sure if the edge detection will be able to separate the focused object. Any ideas? Regards Ziggy

## stereo image capturing hardware

inHi All, I am thinking of starting a hobby project on stereo vision. I would like to minimize my effort on actually getting the images to the...

Hi All, I am thinking of starting a hobby project on stereo vision. I would like to minimize my effort on actually getting the images to the computer via usb or firewire. I have been googling for the past hour and found very few leads. Does anyone here know where to buy a stereo image capture system? Emre

## Normalization in cross-correlation (image processing)

inHi, In connection with pattern identification in images, cross-correlation between the image and a template matrix is often used. Is there...

Hi, In connection with pattern identification in images, cross-correlation between the image and a template matrix is often used. Is there any reason why the means are substracted from the elements before the multiplying them? If the only purpose is to detect similarity, the scaling seems unessecery. Thanks in advance

## Understanding a DCT

inHello, I am sorry for this naive question but it is something that has been nagging me. I wanted to understand the interpretation of the DCT of...

Hello, I am sorry for this naive question but it is something that has been nagging me. I wanted to understand the interpretation of the DCT of any image. These are the questions I have, hope someone can answer them for me: 1. Are DCTs always done on 8x8 pixel sets? If so, each DCT block will consist of 64 basis image coefficients( a white represents a presence and a black indicates and absence...