Hi all, I am a beginner in matlab and i seriously need your help. MY PROBLEM: I have a grayscale image(1024 X 1280) of a pyrovalve(a...

Hi all, I am a beginner in matlab and i seriously need your help. MY PROBLEM: I have a grayscale image(1024 X 1280) of a pyrovalve(a valve used in rocket engines, looks like a small piston cylinder arrangement). I was asked to do fourier analysis(2D) on this image. For that i took FFT2 of the image. I can get the absolute frequency values. I have to make a 3D plot of the frequency mag...

Hi, guys I've got a question on photographic correlation for doing inspection by cross correlation. I can find sub-image inside the original...

Hi, guys I've got a question on photographic correlation for doing inspection by cross correlation. I can find sub-image inside the original image, however, I don't have an idea if the images have been taken at far different distances, so the resolution of the big image and sub-image are different. Can anybody tell me theoratically on this? thank you very much. Sangthong

Is there a free tool for Matlab based (or other) for doing image/video enhancement: 1. Zooming in using various interpolation (bi-cubic...

Is there a free tool for Matlab based (or other) for doing image/video enhancement: 1. Zooming in using various interpolation (bi-cubic etc.), 2. image enhancement using spatial correlation, 3. image enhancement using succeeding images series. Thanks, IM

Hi friends, i am dinesh. i am doing texture analysis and image segmenatation using gabor wavelets in java.. so far i have successfully...

Hi friends, i am dinesh. i am doing texture analysis and image segmenatation using gabor wavelets in java.. so far i have successfully finished doing texture analysis using gabor wavelets.. now i have to do image segmentation.... actually my work is decamouflaging, that is multiple camouflage breaking, finding the objects that are hidden in the given image because of its same texture as t...

Hi! I'm developing an image processing algorithm for the ADSP21369 and trying it into de EZ-KIT 21369... I load the image (640*480 bmp image)...

Hi! I'm developing an image processing algorithm for the ADSP21369 and trying it into de EZ-KIT 21369... I load the image (640*480 bmp image) with the Image Viewer into SDRAM and process it directly from SDRAM. Trying to do it with the DMA I found that there are no significatively difference betwen them. That's possible?? Or I'm doing somethimg wrong?? I measure times like this: STA...

Hi All, I am performing Integer DCT on Lena image. I am using " C "& i am not able to reconstruct the image correctly. Before applying DCT I...

Hi All, I am performing Integer DCT on Lena image. I am using " C "& i am not able to reconstruct the image correctly. Before applying DCT I am subtracting 128 from all pixels of input image. After IDCT i am adding 128 to the result image. I want to compare my results with MATLAB . Is anybody know how to use dct i.e. dct2 function of MATLAB? if anyone has the related code in MATLAB please...

Hi, I have been asked to design a program in Matlab which calculates the FFT of an image, then defocus the image using a Bessel filter, and...

Hi, I have been asked to design a program in Matlab which calculates the FFT of an image, then defocus the image using a Bessel filter, and reconstruct the defocussed image. Now, I find that only analog models of Bessel filters are available in Matlab, though i found a link to a pdf which shows values of the coefficients upto order 10. But, how do i construct a 2D-Bessel Digital filter? I a...

Hello! I am trying to implement an algorithm which is supposed to find the best match of a given (small) image in a larger image. I have...

Hello! I am trying to implement an algorithm which is supposed to find the best match of a given (small) image in a larger image. I have thought about a few (naive) ways of implementation, and recently have been pointed at FT and wavelets, which - if applicable - sound rather interesting for my problem. So I was wondering whether you can give me any tips on whether using those transfo...

hello, i am trying to compare my versus matlab's implementaion of a convolution in the frequency domain. i have a mask that is not the...

hello, i am trying to compare my versus matlab's implementaion of a convolution in the frequency domain. i have a mask that is not the same size of the image (in fact its much smaller). but i fft2 the mask with the dimensions of the image and then convolve with the fft2 of the image. my question i, what method is used for zero padding the mask to be the same size of the image? can...

When digitally mixing an IF down to baseband, one is left with a spectrum that consists of the baseband (Fif - Fmix = 0Hz) and an image (Fif +...

When digitally mixing an IF down to baseband, one is left with a spectrum that consists of the baseband (Fif - Fmix = 0Hz) and an image (Fif + Fmix). If the IF is greater than the Nyquist freq, the image will wrap back into the first Nyquist zone (0 to Fn). Normally the next step in demodulation is decimation, which consists of lowpass filtering out the image (often with CICs) and then drop...

Hi all, I obtained some pictures using camera. It looks to me there are some additive noise that was added to all image pixel components:...

Hi all, I obtained some pictures using camera. It looks to me there are some additive noise that was added to all image pixel components: from what I've observed, there are many small fluctuations/peaks/spikes of height 10-30, while the useful image region has values about 300. I am afraid that such noise has also been added to the useful image region, so the images have been univers...

I read the following in Matlab Help Document of Image Processing ToolBoxes, "FIR filters can be designed to have linear phase, which helps...

I read the following in Matlab Help Document of Image Processing ToolBoxes, "FIR filters can be designed to have linear phase, which helps prevent distortion. " I am wondering what does phase distortion look like in image processing? Also, "Another class of filter, the infinite impulse response (IIR) filter, is not as suitable for image processing applications. It lacks the inheren...

Hi. All, I'm working on Image processing and using Fast Normalized Cross- Correlatino method to compare the template image with the...

Hi. All, I'm working on Image processing and using Fast Normalized Cross- Correlatino method to compare the template image with the Sample image. Fot the theory I use, I need to undestand two terms. 1) Weighted sum and 2) Rectangulare basis function. How should I apply this two the template image ? If anyone knows, reply asap. Thanks & Regards, Chauhan P.D

Hi all, I am facing a headache question in image filtering... I want to apply a low pass filter to an RGB image... I used Gaussian filter,...

Hi all, I am facing a headache question in image filtering... I want to apply a low pass filter to an RGB image... I used Gaussian filter, using Matlab "fspecial" command h=fspecial('gaussian', [31, 31], 5); ... and I am setting the cutoff frequency quite low because I really want to blur the images quite heavily... I applied the filter to each of the RGB planes, using the Matla...

Hi, I have subsampled 4:4:4 image using 15-tap filter into 4:2:2 image. Now, in order to view 4:2:2 image, I need to convert it back into...

Hi, I have subsampled 4:4:4 image using 15-tap filter into 4:2:2 image. Now, in order to view 4:2:2 image, I need to convert it back into 4:4:4 image. I have repeated the chroma samples to create chroma values for alternate luma samples erstwhile without chroma. However, I am doubtful of the method. Do I need to interpolate to create the missing chroma samples? What is generally done in su...

Hi all, I have a bright image which is taken using good camera, and I upsampled it to a higher resolution(say NxN larger size)... and then...

Hi all, I have a bright image which is taken using good camera, and I upsampled it to a higher resolution(say NxN larger size)... and then applied some image processing, color space conversion, gamma transformation, inverse gamma, filtering, etc... and the new image look dark...(or equavalent, the LCD monitor does not support the new image due to its limited dynamic range... what can ...

Hi, I am trying to apply 2D FIR filters to an image. wat is the difference btwn using conv2 and filter2? When i use conv2, I can obtain an...

Hi, I am trying to apply 2D FIR filters to an image. wat is the difference btwn using conv2 and filter2? When i use conv2, I can obtain an image of the same size as the original image, but if i were to use filter2, the result is only a few pixels. another question is upon reading in an image using imread, do i need to convert to ycbcr format before i perform the conv2 or filter2? U...

Hi, I have a basic question on image processing, after FT, I got the casted image on different colors, or different freq. Next is to pass...

Hi, I have a basic question on image processing, after FT, I got the casted image on different colors, or different freq. Next is to pass through a filter to get the freq that I want. I am wondering, I can just pick up any freq I want, and the band of freq I want. Why do I have to construct a filter? Is it really needed? Or how a filter is being used in image processing? thanks PZ ...

Hi folks, If I have a 2D image whose values are purely real, and I take the 2D FT, then I expect the 2D FT to have even symmetry. I think this...

Hi folks, If I have a 2D image whose values are purely real, and I take the 2D FT, then I expect the 2D FT to have even symmetry. I think this applies to a reflection about one axis - that is, half the resulting 2D FT image is a reflection of the other half. So all the information is in kept if I use just one half of the 2D FT image. But does it apply in some circumstances to each quadra...

Greetings, I am looking for a low power image compression for a mobile application. It is meant to compress image data from an image...

Greetings, I am looking for a low power image compression for a mobile application. It is meant to compress image data from an image sensor so it can be transmitted over GPRS. Does anyone have any recommendations? Currently I am still looking for a microcontroller, probably a PIC to do the control functions. I am not sure if any microcontroller will be fast enough to be able to perfo...