Hi, I'm trying to convert an image to frequency domain and back using kiss FFT. The problem is that when I ONLY apply the forward transform than...

Hi, I'm trying to convert an image to frequency domain and back using kiss FFT. The problem is that when I ONLY apply the forward transform than (just after that) the inverse transform I obtain a brightened image. I'm using complex numbers this way: const int dims[2] = {h,w}; // dimensions of fft ( height, width) const int ndims = 2; // number of dimensions. here 2 (2D) kiss_fftnd_cfg ...

anyone could point me out where did i do wrong? it seems that i can't get back the original Lena image after the IDCT(inverse discrete...

anyone could point me out where did i do wrong? it seems that i can't get back the original Lena image after the IDCT(inverse discrete cosine transform) process. the output raw image is nothing more than a grey colored canvas ... //Header files declarations #include #include #include #include //Global declarations const int pixel=256; uns

Dear all, I want to ask the following question: suppose we have 8x8 image pixels, and if we take variance in the image pixel domain, that's...

Dear all, I want to ask the following question: suppose we have 8x8 image pixels, and if we take variance in the image pixel domain, that's quite easy; however, can I compute variance by way of 8x8 DCT domain directly? Anybody throw some lights to me? Thanks a lot, -Walala

In the following website; http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=3234 the image shown is the stereograph of...

In the following website; http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=3234 the image shown is the stereograph of aurora synthesized by Stereographer The original image was taken by S. H. Stefnisson (http://www.iww.is/art/shs/pages/thumbs.html). For detail of Stereographer, visit; http://139.134.5.123/tiddler2/stereographer/stereograph.htm

Hi all, I am trying to design a 2D low pass filter that filters some image. I have decide the cutoff frequency to be 0.2, in terms of...

Hi all, I am trying to design a 2D low pass filter that filters some image. I have decide the cutoff frequency to be 0.2, in terms of normalized frequency in [0, 0.5]. I decided to use Butterworth low pass filter and 7th order. I generate the frequency response using the "lowpassfilter" function as attached below, then by using "fwind1" I got an 2D impulse response of the filter wit...

Hi Friends, Check here http://freevideolectures.com/signals.html for video lectures on Signals & Systems, Digital Signal Processing,...

Hi Friends, Check here http://freevideolectures.com/signals.html for video lectures on Signals & Systems, Digital Signal Processing, Image Processing, Wi-Fi etc.... It also has amazing collection of video lectures and animations on all Engineering and Medical Sciences. I am sure you will be surprised to see such great collection. Do you like it???

hi folks, I am wondering what is the "spectral reflectance" and how to measure it from an image displayed on a CRT monitor or LCD monitor? I...

hi folks, I am wondering what is the "spectral reflectance" and how to measure it from an image displayed on a CRT monitor or LCD monitor? I guess this is a term in the computer vision field? or computer graphics field? I am not sure. Anybody can give some pointers? thank you very much -Gino

Dear all, This should be an diagonal edge detection problem. I know one can use those canning edge detector stuff to do some minus-plus...

Dear all, This should be an diagonal edge detection problem. I know one can use those canning edge detector stuff to do some minus-plus operations and determine the actual edge. But I just want to have a boolean-valued function to answer yes-no whether a diagonal edge presents in 8x8 image block or not. Is there a simpler(faster) way of answering yes-no? Thanks a lot, -Jeonyim ...

Hi Folks Just a quick question to verify if I'm correct. In a real only FFT, I get a mirror image of the peaks in the...

Hi Folks Just a quick question to verify if I'm correct. In a real only FFT, I get a mirror image of the peaks in the output symmetrical about the half way number of points of the FFT. I know this is correct. However with the complex FFT, I only get the peaks(on one side only)...no mirror image. They are at the correct position. Can someone tell me if this is correct or not, and expl...

Questions 1. Does JPEG specification define thumbnail image generation for JPEG images? if so any references on web. 2. How thumbnails...

Questions 1. Does JPEG specification define thumbnail image generation for JPEG images? if so any references on web. 2. How thumbnails are generated for high resolution JPEG images and placed as part of the JPEG file? Any relevant information will be appreciated. George Wilson

hi, I urgently want some easy to implement methods/algorithms for image downsampling.

hi, I urgently want some easy to implement methods/algorithms for image downsampling.

Hi all... I am jayadevan,a student from india.As part of my course curriculum i am doing a project on image processing implemented using...

Hi all... I am jayadevan,a student from india.As part of my course curriculum i am doing a project on image processing implemented using DSP/BIOS. i have to read an image file in the raw file format. but i dont know how to read a file in dsp/bios. my c++ code is FILE *fi; fi=fopen("apple1.raw","rb"); this code segment is not working.it says FILE and f1 is undefined

Hello, I have a gaussian kernel of size [192,192] to be convoluted with an image of size [512,512] for smoothing. Using the FFT property that...

Hello, I have a gaussian kernel of size [192,192] to be convoluted with an image of size [512,512] for smoothing. Using the FFT property that fft of a convolution is the product of the fft of the individual terms (fft(f(t) * g(t))) = f(w)g(w), i could say that smoothedimage = fftinverse(fft(image) fft(kernel)) the problem i am encountering is this: straightforward convolution is easy b...

I bought the below book with software included but I'm the disk is bad. I would like to get in touch with someone who has the source code...

I bought the below book with software included but I'm the disk is bad. I would like to get in touch with someone who has the source code or even the author. Thanks in advance for your help. Signal and Image Processing With Neural Networks: A C++ Sourcebook/Book and 3 1/2 Disk Publisher: John Wiley & Sons; Book&Disk edition (July, 1994) ISBN: 0471049638 I bought the book and I a...

Hi, I want to test my system with different types of input signals. signal of random distribution can be easily generated from matlab. In...

Hi, I want to test my system with different types of input signals. signal of random distribution can be easily generated from matlab. In image processing, usually Lena image is taken as good test case input. what about speech processing. where can i get the sample signals. and how many samples should i consider? can these signals be read direcly from matlab? Tx Karl

Hi all, I just have a question about using Matlab's FFT2 to compute the 2D DFT of an image... An image is input as MxN pixels,...

Hi all, I just have a question about using Matlab's FFT2 to compute the 2D DFT of an image... An image is input as MxN pixels, what should be the unit of the frequency domain, that's to say, what should be the unit of the 2D DFT matrix returned by the Matlab FFT2 command? What does each grid of those MxN output matrix represent? If I attach some physical units to the i...

There is a special session on Speech, Audio, Video and Image Processing using AI at the 5th Indian International Conference on Artificial...

There is a special session on Speech, Audio, Video and Image Processing using AI at the 5th Indian International Conference on Artificial Intelligence (IICAI-11) will be held during December 14-16, 2011 in Tumkur (near Bangalore), India. Please see the website: http://www.iiconference.org/savi.html . We invite draft paper submissions. About the conference: The primary goal of IICAI is t...

There is a special session on Speech, Audio, Video and Image Processing using AI at the 5th Indian International Conference on Artificial...

There is a special session on Speech, Audio, Video and Image Processing using AI at the 5th Indian International Conference on Artificial Intelligence (IICAI-11) will be held during December 14-16, 2011 in Tumkur (near Bangalore), India. Please see the website: http://www.iiconference.org/savi.html . We invite draft paper submissions. About the conference: The primary goal of IICAI is t...

Dear Colleague, We are pleased to invite you to the International Conference VipIMAGE 2013 - IV ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL...

Dear Colleague, We are pleased to invite you to the International Conference VipIMAGE 2013 - IV ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING (www.fe.up.pt/~vipimage) to be held October 14-16, 2013, in Melia Madeira Mare Hotel, Madeira Island, Funchal, Portugal. Possible Topics (not limited to) • Signal and Image Processing • Computati

Dear Colleague, We are pleased to announce the International Conference VipIMAGE 2015 - V ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION...

Dear Colleague, We are pleased to announce the International Conference VipIMAGE 2015 - V ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING (www.fe.up.pt/~vipimage) to be held October 19-21, 2015, in H10 Costa Adeje Palace, Costa Adeje, Tenerife, Spain. Possible Topics (not limited to) - Signal and Image Processing - Computational Vision - Medical I