**how to divide an image to blocks of 8x8 image and access each block separately**Hi,
I am looking for some help in dividing an image to 8x8 block and access each block separately. My image I is of size 640x480. I need to divide the image into subblocks of size 8x8 and have to find histogram of each block separately. blkproc is not helping as I cannot access each block separately. If someone can help me with some working code, it will be great.
Ayan
"Ayan " <a.chaki@lycos.com> wrote in message <hu4tta$qo2$1@fred.mathworks.com>...
> Hi,
>
> I am looking for some help in dividing an image to 8x8 block and access each block separately...

**dividing a color image image in overlapping blocks and finding motion blurr for each block**i m doing a project on "forgery detection using motion blur". In that, i need to divide my image in overlapping blocks and then process each block. Can u please provide a code snipplet for the same.
...

**Reading in big images block by block**The functions imread and imwrite read/write the whole image. Thus if
images are really big the system cannot allocate enough memory for it
and thus the call fails.
Most C libraries are written so that they read in the image block by
block, i.e. if the image is 7936x7168 you would read in blocks of 64x64
or 128x128.
E.g.
open('a.tif')
for r = 1:64:7168
for c = 1:64:7936
read 64x64 elements from r'th row, c'th column
process block
Is this possible in MATLAB's IP toolbox (Release 12), or would I have to
write mex files to do it. Thanks,
P...

**divide image into blocks and preformcertain operation on each block**hi,
I would like to thank every one help me in answering my questions
i am working on project for fingerprint analysis and classification,
I need to divide my image into blocks of size W x W where W=16 and
find the variance of each block then display the variance image I use
this operation to segment the foreground from the background I can
not divide the image ,is there any one how can help me and I will be
very thankful to all.
alyaa.
alyaa abdalhussein wrote:
> hi,
> I would like to thank every one help me in answering my questions
> i am working on project for fingerprint anal...

**Overlaying contours on image changes image colors**I'm trying to overlay line-contours of one grid ontop of filled
contours of different grid. The data values of the two grids are
orders of magnitude different. When I overlay the line contours, the
colors of the filled contours change radically.
For example:
x = repmat([1:100],1,100);
y = x' + 1000;
contourf(x)
colormap('jet')
hold on
contour(y,'k')
After the first filled contouring of x, the colors span the "jet"
color scale. Once I overlay the line contours of y, the colors of
the "x" filled contours all change and reflect a very nar...

**Dividing an image into 8x8 blocks and applying svd on each block**can any one plz tell me how should i divide an image into 8x8 subblocks and apply svd on each sub block for image watermaking
...

**Dividing an image into 8X8 block and find histogram of each block**Hi,
Can somebody help me with a code snippets to divide an image of size 352*288 to 8x8 blocks and to find histogram of each block? blkproc is not helping me as i need to access each block separately to find the histogram. A working code snippets will really help me. Thnaks in advance.
Regards,
Ayan
"Ayan " <a.chaki@lycos.com> wrote in message <htnkf8$j1j$1@fred.mathworks.com>...
> Hi,
> Can somebody help me with a code snippets to divide an image of size 352*288 to 8x8 blocks and to find histogram of each block? blkproc is not helping me as i need to access ...

**Image contour**I have a matrix of 0-1. I want to estract the contour and to obtain a
matrix (2 x N) with the ordinated values.
I've tried with the function "contour" but it gives me not ordered
matrix.
thanks,
Pietro
In message ef18335.-1@webx.raydaftYaTP, Pietro Mancosu burbled:
> I have a matrix of 0-1. I want to estract the contour and to obtain a
> matrix (2 x N) with the ordinated values.
> I've tried with the function "contour" but it gives me not ordered
> matrix.
Contourc will return a matrix with the vertices of the calculated contours.
You can then parse t...

**image contouring**Hi friends can someone help me to get the contour of an image?
Have you seen the contour() and the surf() functions? Is that what
you mean?
Thank you for that.But here first i've to binarize the image by otsu thresholding and asked to get the contour of that by subtracting the eroded image from this black n white image.plz do help.
The perhaps you're thinking of the bwboundaries() function, as used in
my demo:
http://www.mathworks.com/matlabcentral/fileexchange/25157
Personally I'd call this "outlining" or 'finding the boundary of"
rather than contour...

**Contour an image**Hi all,
I'm trying to figure out how can I put a contour in my image. I'll try to explain it. I have one image generated from a matrix and I'm using the imagesc function to show it.
After that I'm using contour function and it give me an image of contours from my initial image. At this point I have two images, the original and the contours image.
What I want to do is merge those two images. But from the contours image I want just the 'edges'. I don't know if this's the best way or if matlab already have a function to simplify my life.
...

**image into blocks**i've to segment characters in a numberplate.after doing
vertical and horizontal projection plate should be
converted into vertical as wellas horizontal blocks.how
could i convert plate image into horizontal and vertical
block.i'm using matlab6.5.kindly help me
...

**Image block**hello everyone ..
I am having an image of 512*512 in .jpg format. i want to convert this image into blocks using MATLAB. Anyone could help me to find the procedure for it.
thnks....
On Nov 24, 11:03=A0pm, "amitesh kumar" <amiteshkuma...@gmail.com> wrote:
> hello everyone ..
>
> I am having an image of 512*512 in .jpg format. i want to convert this im=
age into blocks using MATLAB. Anyone could help me to find the procedure fo=
r it.
>
> thnks....
---------------------------------------------
You mean like extracting out sub regions into separa...

**Convert 4096 (8 X 8) image blocks into an image**Dear all, I'm working on watermarking of digital image. A portion of the code is shown here:
clc;
clear all;
close all;
start_time = cputime; %Starting Time of Execution
I = imread('lena.jpg');
[r, c]=size(I);
bs=8; % Block Size (8x8)
nob=(r/bs)*(c/bs); % Total number of 8x8 Blocks
% Dividing the Cover image into 8x8 Blocks
for i=1:(r/bs)
for j=1:(c/bs)
dctimg(:,:,kk+j)=dct2(I((bs*(i-1)+1:bs*(i-1)+bs),(bs*(j-1)+1:bs*(j-1)+bs)));
end
kk=kk+(r/bs);
end
size(dctimg) = 8 8 4096.
How can I get size(dctimg) = 512 X 512;
Please Help. thanks in ...

**image blocks**Dear all,
I am new to Matlab and I would like to ask a simple question about
WPT.
I have the original image which has 512x512 size and it was
transformed with WP (e.g. 4 levels). I would like to know how to find
the rows and columns of any of the WP blocks. Not the reconstructed
entire image. Only the rows and columns of the last level (e.g. level
4) of the blocks.
Please let me know the code for this.
Thank you very much for your time.
SIncerely,
charles
...

**A contour of an image**when i use contour command in matlab
m = imcontour(Image, 1) what i got is a 2-dimensional array with only
two values in the y-axes.. but what i need is
if i have a m*n image i need an m*n array which contains the bit
representation of the contour image.. i urgantly need this function.
Thank you in advance
On Sun, 11 Apr 2004 17:52:32 +0000 (UTC), Muna_khy@yahoo.com (Muna)
wrote:
>when i use contour command in matlab
>m = imcontour(Image, 1) what i got is a 2-dimensional array with only
>two values in the y-axes.. but what i need is
>if i have a m*n image i need an m*n array ...

**Dividing an image into 8x8 blocks and applying svd on each block #2**can any one plz tell me how should i divide an image into 8x8 subblocks and apply svd on each sub block for image watermaking
On 2/15/2012 2:13 AM, sreenath reddy wrote:
> can any one plz tell me how should i divide an image into 8x8 subblocks
>and apply svd on each sub block for image watermaking
may be blockproc() is you have the image processing toolbox:
http://www.mathworks.com/help/toolbox/images/ref/blockproc.html
for the handler then, try svd on it. see if that works.
--Nasser
"sreenath reddy" <rsrnthr@gmail.com> wrote in message <jhfpeq$lbn$1@newscl01...

**contours on image**Hi all
i am trying to plot contours on a jpg file which I read into Matlab. I tried using contourf but that is filling the contours using other colors than the pic. As i am new to this software could any one help me how I could plot contours on the image?? Any help will be greatly appreciated.
Regards
On Oct 20, 12:31=A0pm, "A D" <nshauka...@yahoo.com> wrote:
> Hi all
> i am trying to plot contours on a jpg file which I read into Matlab. I tr=
ied using contourf but that is filling the contours using other colors than=
the pic. As i am new to this software could any one...

**block image**how to make images into 8x8 block using the function for-next. don't use syntax 'blkproc'
...

**How to copy non-integral sized blocks for block matching during image correlation?**Hi guys,
In my current implementaion of image correlation, I want to compare the intensity difference of two blocks with non integral size. Could you please help me compting the intensity difference of matching blocks?
For example, the start and end postions in row and column for 2 matching blocks blk1 and blk2 in 2 images respectively are defined as the following,
blk1 = [1 1.5; 2.5 3];
blk2 = [2 2.5; 3.6 4.1];
and our purpose is to computer intensity difference of these 2 blocks. I use grayed image to represented intensity.
I don't know how to extract such blocks out fo...

**help on image processing, image segmentation, pattern recognition and contour tracking**Dear all,
I have to process a stack of 5000 images and locate droplets as well as cloud structures in these images. I did a lot of image processing with Matlab but all the techniques I applied are not very reliable to extract the features I am interested in out of the images. I put two sample images of my measurements on a website so that you get an idea of what I am talking about. Feel free to download the images if you like. I also created some movies of the images that can be found on the same website.
Link to website:
-------------------
http://wwwuser.gwdg.de/~fwinkel/images.html
...

**Block Change Tracking, Incrementally Updated Image Backup and Block Corruption Detection**(Posted this per GoogleGroups few days ago but never found it back in
the group.)
Hi,
We were discussing new RMAN features and touched the topic Block
Change Tracking (BCT).
A theoretical drawback of BCT could be of that not all blocks are
checked daily for corruption in a BCT setup.
If I combine BCT with Incrementally Updated image copies, in such I
way that I will only take incremental backups, how will I find my
corrupt blocks?
1 - is there indeed a risk of not being early warned for a bad block
when switching to BCT+Incremenally Updated
2 - what would be a wise mitigation of this risk?
...

**dividing images into blocks**I'm using matlab7.8.I want to divide images into blocks .I know that it can be done using blkpoc but I have to do it using for loop.Please help me!!!!!!!!!!!!!!!!!!!!
Soumya,
I am not sure why would you need a for loop while the blkproc is available and faster? But here is a version of the solution, you can also reshape the image into a 1D vector and process blocks of size 1xn with only one for loop.
image=zeros(100,100);
[M N]=size(image);
n=3; % a 3x3 block
m=3; %
for i=1:n:(N-n)
for j=1:m:(M-m)
%Your process, here I choose to assign a random value to each block
image(i:(i+n-1)...

**dividing the image into block**I can't understand how i divide the image of fingerprint into block?
Please help me . Plz give me the MATLAB code of it.
Thanks
Please give me a better definition of "block." And of "divide."
Do you simply mean something like
subImage = fullImage(row1:row2, column1:column2);
...

**decomposition of image into Blocks**Hello everyone
i am trying to decompose a 512*512 .jpeg image into four blocks using some row and column concept.but i am unable to code this. if any can help me in coding part plz help me. Basically i am doint this decomposition for finding the corner points. i tried quadtree concept also . but i was unable to do this . here the coding part which exactly i am doing...
I = imread ('C:\Documents and Settings\admin\My Documents\Downloads\lena2.jpg');
I = I(1:512 ,1:512);
subplot (1,3,1);
imshow (I);
C = cornermetric (I);
C_adjusted = imadjust (C);
subplot (1,3,2);
imshow (C...