**Filters : a library implementing image filters and image processing functions**Dear members,
I would like to inform you that we have released our last version of
the open source library "Filters". We will appreciate your feedback.
link : http://filters.sourceforge.net/
Regards
In short, no source code = crap.
Come back when you've got something real to download, a few demos
and some API's don't equate to much these days...
edurand wrote:
> Dear members,
> I would like to inform you that we have released our last version of
> the open source library "Filters". We will appreciate your feedback.
> link : http://filters.so...

**Image smoothing using an isotropic Gaussian filter**I want to smooth an image using an isotropic Gaussian filter with
standard deviation of =F3x, =F3y =3D 3.
To achieve this, can I use the fspecial function to create the
smoothing filter as follows:
gauss_filter =3D fspecial('gaussian', [x y], 3);
With [x y] being the size of the filter to apply to the image. If not,
what should I be using instead?
Also, what is the relationship between the number of filter samples
required and the standard deviation used?
Thanks.
...

**what is the cutoff frequency for Gaussian filter in Matlab imaging processing?**Hi all,
This is a continuum of the question I post one moment ago. I've obtained a
11x11 impulse response for that 2D low pass Butterworth filter of 7th order
and 0.2 cutoff frequency(normalized frequency range [-0.5, 0.5])...
My friend claimed that the following 11x11 h impulse response have negative
values in it so it is no good for image filtering... (btw, why are there
negative values? )
He suggests that I forget these fancy filters and use a plain Gaussian
filter for low pass filtering... however I looked into the "fspecial"
command in Matlab image toolbox... and I ...

**padding gaussian matrix for 2d filtering image process**I must do a Gaussian Filter on image,
I have matrix data image in a 100x100 matrix.
I generate a 7x7 gaussian matrix for filtering,
how do I padding the gaussian matrix for obtain a 100x100 matrix ?
with zeros value around gaussian value ?
thank you so much.
anyone can help me ?
...

**(image process) are there any guidelines on how to design good filters to enhance an image?**dear all,
I am facing the following problem that I need your help:
We have in our experiments some special images need to be processed. My task
is to look at these images and see how to improve/enhance them. In fact we/I
have no idea on how much enhancement we can get.
So what I've done in the past month is to play with different kind of
filters to try on the images. We use PSNR as judgement. It turns out I found
a Gaussian 3x3 filter has particularly high enhancement to the images,
comparing with other filters provided by Matlab, such as "laplacian",
"averaging"...
...

**GUI-image processing(open image and process)**Hi,I have a problem with my GUI..
In my GUI there are two axes and two buttons..
User ,will click in the first button ,he will load a image and the image will be shown in the wirst window of my GUI.
Then the user will click on the "segmention" button and the segmented image will be shown in the second window.
My problem is ,that the Segment_Callback can't read the file name.
I posted you my code and the errors.
Thanks a lot in advance!!
function OpenImage_Callback(hObject, eventdata, handles)
[filename, user_canceled] = imgetfile
axes(handles.SimpleImage)
title(...

**image processing and filtering**Hi,
My program is to read some images and then high pass
filter to filter the image and plot out the rms values.
I’m able to read and display the image. But the filter got
problem.
The error message:
??? Undefined function or variable 'filterarray'.
Error in ==> D:\MATLAB6p5p1
\work\signalimage\FocusImages\new.m
On line 47 ==> lengthoffilter=length(filterarray);
I can’t continue. Anybody know how to troubleshoot?
Below is the program.
Thank you.
Regards,
Sem
--------------------------------------------------
clc;
close all;
clear all;
for picture=1:...

**Irradiation Event UID for an image that was created by processing another image using different image processing parameters**Hello,
I have a question regarding how to populate the Irradiation Event UID in the following scenario:
Image A is acquired on a DR or CR system.
Image A is given an Irradiation Event UID.
Image B is created by processing Image A using different image processing parameters.
Should Image B have the same Irradiation Event UID as Image A since they both come from the same irradiation event? It seems that they should.
If both Image A and Image B are given the same Irradiation Event UID and a Radiation Dose Report is created, is there any problem with having more than one imag...

**a question about image filtering: what should be the scaling factor after image filtering?**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 Matlab "imfilter"
command.
My input image was made sure to be within [0, 1] for each plane. So for each
RGB plane, the range is [0, 1], [0, 1], [0, 1]. The mean of each channel
are: R:...

**GUI-image processing(open image and process) #2**Hi,I have a problem with my GUI..
In my GUI there are two axes and two buttons..
User ,will click in the first button ,he will load a image and the image will be shown in the wirst window of my GUI.
Then the user will click on the "segmention" button and the segmented image will be shown in the second window.
My problem is ,that the Segment_Callback can't read the file name.
I posted you my code and the errors.
Thanks a lot in advance!!
function OpenImage_Callback(hObject, eventdata, handles)
[filename, user_canceled] = imgetfile
axes(handles.SimpleImage)
title(...

**Applying a gaussian filter to an image**Hi,
I am quite new to Matlab. Is there a built-in function to apply a
gaussian filter over a color image?
If not, any hints on how to do it?
Also, if there is a built-in function, can I tell it to handle edges
differently (like, using kernel renormalization?)
Thanks a lot in advance.
Did you try this?
filterMask = gausswin(dy) * gausswin(dx)';
imageOut = filter2(filterMask, imageIn);
Where dx and dy is the size of the rectangular filter mask.
I would do the edge handling manually by padding, but maybe there is
a better way to do that.
Regards
Markus
[url=http://zvxcxw.googlepages...

**image processing**Hi,
If I am using scipy.ndimage.gaussian_filter() for filtering an image,
how to do the inverse filtering? In general how to do this using
scipy.ndimage?
Thanks
suresh
In article <5bfefbb6-89a8-49f6-9f02-7d36dfbc0f16@c29g2000yqd.googlegroups.com>,
suresh.amritapuri <suresh.amritapuri@gmail.com> wrote:
>
>If I am using scipy.ndimage.gaussian_filter() for filtering an image,
>how to do the inverse filtering? In general how to do this using
>scipy.ndimage?
http://projects.scipy.org/mailman/listinfo/scipy-user
--
Aahz (aahz@pythoncraft.com) &...

**Gabor filters in Image Processing**i have to filter my images by Gabor filters. I write my Gabor
function. It takes the parameters of "Size", "Standard Deviation",
"Period" and the "Orientation of gabor shell".
My purpose is to find rectangles in the images. After filtering, i
will binarize my images, and i will approximately find the places of
rectangles in my images.
That seems ok. but every images have different backgrounds and
illumination level. Although i have done preprocessing, the output of
filtering is not good. I have chose the parameters of filters by trial
and err...

**IMAGE PROCESSING**Hi,
I have an RGB image and without converting it to grayscale I want to
do median filtering. Is it possible , if so how ?
I tried to create the median filter but it give me following error
Function ORDFILT2 expected its first input, A, to be two-dimensional.
Error in ==> ordfilt2>ParseInputs at 135
iptcheckinput(A, {'numeric','logical'}, {'2d','real'}, mfilename,
'A', 1);
Error in ==> ordfilt2 at 51
[A,order,domain,s,padopt,msg] = ParseInputs(varargin{:});
Error in ==> medfilt2 at 57
b = ordfilt2(a, order1, domain, padopt);
Erro...

**matched filtering (image processing)**Hi,
Have anyone done any image processing function called matched
filtering. I have two input images (same size). The output should be
the correlation value between two image. I tried corr2 function but
it doesn't work well when the image is shifted to left or right (not
shifting invariant). I hope that matched filtering will solve this
problem.
thanks
xcorr2 or conv2 should do the job, if you design your matched filter
accordingly.
/Johan
yo wrote:
> Hi,
> Have anyone done any image processing function called matched
> filtering. I have two input images (same size). T...

**image processing Gaussian smoothing**why Gaussian smoothing is commonly used with edge detection?
what is the most suitable smoothing method for __edge detection algorithm? Is it Gaussian smoothing? If so, why?
...

**sinc filter for image processing**Hi,
I want to use sinc filter for image processing. As I understand for its theory this can be suitable for edge detection operation.How can I do this in Matlab? Could you help me about this operation?
Thanks.
On Sep 22, 4:28=A0am, "elysion87 " <saki...@gmail.com> wrote:
> Hi,
>
> I want to use sinc filter for image processing. As I understand for its t=
heory this can be suitable for edge detection operation.How can I do this i=
n Matlab? Could you help me about this operation?
> Thanks.
-----------------------------------------------------------
Yes. Set u...

**Image processing: high pass filter**Hey guys. I kinda need some help here. I'm doing some image
processing and I'm programming some filters. Here's the
case of a high pass filter, for instance with a 5x5 kernel
which has this form (I stole it from the IPP):
0 -1 -1 -1 0
-1 -1 -1 -1 -1
-1 -1 21 -1 -1
-1 -1 -1 -1 -1
0 -1 -1 -1 0
So, the negative coefficients here may turn the result of
applying the kernel to be negative for a particualr pixel,
or maybe bigger than 255. Is there any normalization
technique?
I tried uint8 but the results are far worse than what I get
when applying the filter in IPP
Than...

**CVS for image processing and adaptive filter**Hi my name is Alam, and now i'm working for my final project in my university.
My task is to set up a vision based tracking system. It use a single
firewire camera to detect the presence of an object using some image
processing algorithm that give an information about object coordinate
position. I use this information as the input for Kalman Filter so that
i can predict the object position for the next state of my system.
I just want to know if I can do that job using LabView and CVS 1454 (
because my supervisor order me to use it ). If it is possible I also
want to know how can i send ...

**matlab image processing matched filter**hi to all
Im new to image processing and also to matlab. I have a project which needs to extract blood vessels from retinal image by using matched filtering and It looks like I have to desgin one but I have no idea what is a matched filter. Can some please explain me image processing with matched filtering
thank you
ANIL
Why do you need to use a matched filter? Why not use any method that
you can think of that will work?
If it's your homework problem, then review your notes from the class
lectures or ask your professor.
If you have a MATLAB question, such as how to use im...

**processing and filtering image spot satelital**i can any process with matlab to image spot5
satellite.
You have any practice with this?
tank regards
...

**the point of passing through a filter in image processing**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
PZ wrote:
> 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 tha...

**Image processing threshold and median filter**Hi,
i am new to matlab. I am currently processing sets of data, which the data is in 520x688 pixels.
Now, for example in the matrix 520x688, there are some values that more than the threshold value, say my threshold value is 3000, and say we take only 7x4 array like below
2330 2689 2072 2864 2763 2865 2695
2450 4210 2550 2543 2560 2654 2986
2564 2564 2564 2564 3514 2014 2045
2465 2555 2987 2106 2541 2644 2304
so, in that matrix, i have got 2 values that is more than 3000, which are 4210 and 3514. So what i wanted to do is the matlab to find the value that is more than 3000, an...

**Using an image mask as a filter for video processing**I am trying to measure the change in area of an object for a neurophysiology assay. Currently, I load a video, crop it, apply a rgb filter to the frames of interest and pass that information onto bwlabel. I use bwlabel and regionprops to calculate the change in area for each frame, saving the data as a vector providing me with a nice curve. My problem is this: i want to calculate the area of an individual object, while excluding other objects in frame within the parameters of rgb filter . The rgb filter works okay but it can be too lax or stringent depending on the circumstances.
I want ...