**Maximum/minimum autocorrelation factors for multivariate images**hello all,
I am struggling very hard to understand Maximum/minimum
autocorrelation factors for multivariate images. I am a biologist and
want to apply this technique into multivariate imaging of cells where
the image is in layers of different wavelength excitations. So 2-D
images layerd.
I found people able to find it better than principal component
analysis, to correlate the spatial variation.
PLease if u know some program send it to me. u gays have helped me a
lot and I appreciate that,
--H
...

**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:...

**image correlation and autocorrelation**Hello forum,
this is a simple one:
I found two forms of autocorrelation for 1D signals:
biased and unbiased.
Does anyone know the difference?
Also, all the signals or images we work with are finite in length.
If autocorrelation is carried out, we need to shift the image around with
respect to itself.......( that would correspond to the lag (shift) in
space).
In order to do that, do we first need to pad the images with a lot of
zeros?
If my image is NxN, I guess the zero padded image should be 3Nx3N, to make
space for the lateral shift of the identical copy, right?
thanks
fisico30
On Feb...

**noise autocorrelation of an image**Hello
how I can calculate auto-correlation of Gaussian noise for an image?
thanks
...

**image quality factor**Hi,
How can i find the quality factor of a jpeg image.
for eg to change an image quality, i use imwrite(x,'filename.jpg','quality',30);
how can i display/find this quality info of an image?
Thanks!
help imfinfo
it shows information about the image
On Oct 29, 3:33=A0pm, "a b" <vinet...@yahoo.co.in> wrote:
> Hi,
> How can i find the quality factor of a jpeg image.
> for eg to change an image quality, i use imwrite(x,'filename.jpg','qualit=
y',30);
> how can i display/find this quality info of an image?
> Thanks!
...

**factoring wx.Image**Hi,
I want to factor (red, green and blue at the same time) an image using
wx but without any GUI display or windows but it keeps crashing and if I
set the checks to ignore it, it doesn't produce the images at all.
It looks like this:
import wx
img = wx.Image("star.jpg",wx.BITMAP_TYPE_BMP)
factor = 1
for i in range(1,30):
image = img.AdjustChannels(factor, factor, factor, 1)
fname = "star." + str(factor) + ".jpg"
img.SaveFile(fname,wx.BITMAP_TYPE_JPEG)
factor+=1
What am I missing here? What am I doing wrong? Can this even be done
with only...

**image registration autocorrelation**Hi group,
Can someone recommend some matlab tools that do image registration
using autocorrelation? Thanks a lot for the help!
...

**Weighting factor in Image reconstruction**Hi..
Anybody have any idea how to calculate in matlab the weighting
factor(matrix) in the Algebraic Reconstruction Techniques. (Image
Reconstruction)
Its in 3rd page in this link
<http://rvl4.ecn.purdue.edu/~malcolm/pct/CTI_Ch07.pdf>
Lucky wrote:
>
>
> Hi..
> Anybody have any idea how to calculate in matlab the weighting
> factor(matrix) in the Algebraic Reconstruction Techniques. (Image
> Reconstruction)
>
> Its in 3rd page in this link
> <http://rvl4.ecn.purdue.edu/~malcolm/pct/CTI_Ch07.pdf>
>
It is "just" the intersection area. You coul...

**Scaling Factor in image Mosaics**Hi
i'm working on image mosaics.
After applying transformation the images are stitced together.If one image contains zoomed information i want to get the scaling factor by which it is zoomed.
Help needed guyzz.
Aamna
You can't unless you know something or assume something. Let's say
you have a photo of a ball. How do you know if it's a ping pong ball,
a baseball, a softball, or a volleyball, the moon, or the sun? If all
you know is that it's a bright ball, you can't tell the "real world"
size of the image or its zoom factor.
...

**Get Quality Factor of JPEG Image...**Does anyone know of a quick and easy way to use MATLAB to find the Quality Factor of a JPEG compressed image?
Thanks.
...

**FFT based scaling factor for images**Hi!
I have 400x400 images at different magnifications. I want to downscale the images upto 5 times. I want to select the best scaling factor for an image so that I get a good contrast against different objects in the image given that there is a veriety of object sizes. And hence I get a spreaded Fourier spectrum. I want to know how can I find the best scaling factor on the basis of FFT2 so that I have the least loss of information in the image. I mean the truncation of Fourier spectrum against a certain frequency component.
Thanks in advance,
Regards,
Awais
On Apr 21, 6:38=A0pm, "Muhamma...

**Calculate Q factor to determine image quality**Hi,
What is Q value of an image?Would anyone have inputs on being able to
calculate it?
thanks,
MR
I guess you are referring to the Q value for JPEG compression (old
JPEG, not JPEG 2000). The value control the quantization stepsize and
hence the quality of the compressed image. It ranges from 0 to 100,
where 100 is the best.
There is not such measure of Q value of any arbitrary image.
Sam
yes,that is right.
But iam trying to develop an algorithm to calculate Q value of JPEG
image.ANy inputs on how to do it?
-MR
Sam wrote:
>
>
> I guess you are referring to the Q value for JPEG ...

**shape factors from tomography images, help needed**I have got a set of 2D x-ray tomography images of a potato-shaped
object. I am interested in calculating the sphericity of this object
as an indicator of the 3D shape of the object. Any ideas on how to do
this?
For the object I have a set of approx. 400 .bmps that correspond to
adjacent cross section of the samples.
Any help would be very helpful.
Dani
The first step would be to segment the 2D images to identify the voxels
contained in the object. There are programs freely availabe over the
internet which you can download and use. For example
http://www.mathworks.com/matlabcentral/filee...

**image registration/find scale factor and recover it**Hi I'm using the code here http://www.mathworks.com/matlabcentral/fileexchange/19731-fourier-mellin-image-registration/content/Register.m
I want to find the "scale factor" of the second image that has been translated,rotated,and scaled then recover the scale, can any one help me?!
...

**How to manually calculate decay factor in a PET Image?**Hi all,
I've tried to find reference in the standard as to how decay factor
(0054,1321) is calculated, but I can't seem to find it. The reason I'm
asking is that I would like to be able to calculate SUV factor from
images that haven't been decay corrected and I assume that I would
just calculate the factor and put it into my SUV equation.
Any help is welcome.
Much thanks,
Henri
...

**Should Estimated Radiographic Magnification Factor used for measuremnts in CR images?**Hi,
I've read the post below about how measurements should be done on projection radiography but I have some questions about.
https://groups.google.com/forum/?hl=en&fromgroups=#!searchin/comp.protocols.dicom/estimated$20radiographic$20magnification/comp.protocols.dicom/kDMQH64lpXc/yJgLaHCRECoJ
- In case a CR image contains Estimated Radiographic Magnification Factor, should it be used to magnify Imager Pixel Spacing values?
For what I've read in the standard it seems it's not a valid tag for CR, but if it is present, what should I do? Ignore it or use it?
Now I&...

**Shape factors from tomography images, sphericity >1 !!... help please**Dear all,
I have been going round in circles trying to solve a problem. I am
sure that you can help me.
I have a set of images (.bmps) from tomographic analysis of a rock.
The images are adjacent to each other (from image number n to image
n+1 there are no missing pixels, if you could put them all together
they would reconstruct the whole sample -up to the resolution of the
machine, of course).
I am after calculating some sort of shape factor to characterize the
shape of the rock. I thought about sphericity, calculated as:
sphericity = ((36piV^2)^(1/3))/A
where V is the volume of my parti...

**Image: DBSCHEMA Question: Calculating Blocking Factor on new TurboIMAGE database**I need to figure out how DBSCHEMA calcs the blocking factor on a TurboIMAGE
dataset (master or detail) when it is CREating a new database.
I have to admit I am clueless on how to calculate this number so any help from
the gurus out there would be very much appreciated.
TIA,
Brian Donaldson.
Example:
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Brian,
I could tell you, but then everyone would c...

**spectral image from elevation image image**Dear friends,
I have an elevation satellite image that each pixel in this image has
elevation value. For example, if we select one pixe (e.g.
image(10,10)= 1300 m) which is the elevation value for this pixel
location. I need to convert this elevation image into spectral image
so that each pixel will have a spectral value (RGB value).
I would apprecaite any comments or suggestions regarding this.
Best regards
Nadir
...

**Binary Image to Indexed Image to RGB Image**How will we convert binary image to indexed image? And then the indexed image to RGB image in Matlab?
...

**Image on Image help**I'm a newbiwe trying to position one small image on top
of a larger one. Based on various examples, I'm trying the
solution below. Only problem is that it doesn't work :-(
Both x and y in the example below always seem to be 0.
Any pointers would be appreciated.
Jim Buzbee
<html>
<body>
<br/>
<br/>
<br/>
<img src="relief.jpg" width="640" height="320" id="base"/>
<img src="overlay.gif" width="10 height="10" id="overlay"/>
<script>
document...

**want to texture map and image with image + return image**Matlab has an example of texture mapping using surfaces but besides that it returns an surface rather than an image, it doesn't seem to do what I want anyway. That is, it seems to be a light projection but what I want is not the same as if I printed a cloth with my picture and dropped it onto a real 3d surface.
Ex: Say I have an input image that's just a bunch of evenly spaced horizontal and vertical lines (like graph paper). Let's say I printed that on a sheet and made a physical model of hills and then dropped that sheet on top of those hills. When viewed from above, the ...

**Take an image from an image**I'm new to Gimp and am having a blast. I'm learning everything from
reading posts here and from the User Manual.
My question is, what's the best way to take an image from an image? In
other words if I have a picture of two people what's the best way to
take one person out.Just the person's outline not any background.
I've been using the free select but that all depends on the steadiness
of my hand using a mouse to cut the image out.
Is there a better way?
Thanks,
Larry T.
LT wrote:
> I'm new to Gimp and am having a blast. I'm learning everything from ...

**how to hide image in an image?**hello,
these days i am trying some hiding process in an image. Like hiding some text in an image or hiding image in an image.
Let suppose i have image of 256x256, and i want to hide another image of same size or of smaller size. how can i do that?
thanks in advance.
On May 6, 12:45=A0am, "Learner " <farhan7...@gmail.com> wrote:
> hello,
>
> these days i am trying some hiding process in an image. Like hiding some =
text in an image or hiding image in an image.
>
> Let suppose i =A0have image of 256x256, and i want to hide another image =
of same size...