I want to vectorize the array : final
I made this code to make red the pixels of the array I
bw : black and white array
I : the original image
final : the array i want to store the values
for i = 1:sz1
for j = 1:sz2
if (bw(i,j)==1)
final(i,j,1)=255;
final(i,j,2)=0;
final(i,j,3)=0;
else
final(i,j,1)=I(i,j,1);
final(i,j,2)=I(i,j,2);
final(i,j,3)=I(i,j,3);
end
end
end
I don't want to have any for/loops.
Have anyone an idea?
Thanks
Thanks! Solved it:
final=I;
final(bw==1)=255;
Related
I'm trying to learn how to segment an image using Normalization Cut. My problem is that I would use superpixel and then NCUT, but the cut_normalized method gives me a single value, and so if I plot it, I have a single color, as follows:
This is my code:
def normcut_segmentations(img):
labels, superpixels = get_super_pixels(img)
g = graph.rag_mean_color(img, labels, mode='similarity')
ncuts_labels = graph.cut_normalized(labels, g)
print("Segmentation label: ", np.unique(labels))
print("NCUTs Label:",np.unique(ncuts_labels))
ncuts_result = color.label2rgb(ncuts_labels, img, kind='avg')
return ncuts_labels,ncuts_result
To read the image (that is a bitmap), I use skimage.io.imread(img_filename).
What would be the problem?
Thanks!
I'm new to ImageJ and ImageJ macro. I started to make a macro that apply the "Find Maxima" function on an image. Then I would like to test each pixel spotted as maxima to filter them by value. How can I loop through all the points of the selection into my macro ?
Thanks
Finally I found an answer :
threshold = 254;
getSelectionCoordinates(x, y);
for (i=0; i<x.length; i++){
if(getPixel(x[i], y[i]) < threshold){
setKeyDown("alt");
makePoint(x[i], y[i]);
}
When I try to use fraxel's answer on
http://stackoverflow.com/questions/10269099/pil-convert-gif-frames-to-jpg
on the image http://24.media.tumblr.com/fffcc2d8e980fbba4f87d51ed4916b87/tumblr_mh8uaqMo2I1rkp3avo2_250.gif
I get ok data for some, but then for some I get missing data it looks like, e.g.
Correct
Missing
To display these I use imagemagick's display foo* and then use space to move through the images ... is it possible imagemagick is reading them wrong?
Edit:
Even when using convert and then displaying via display foo* I get the following
Could this be a characteristic of the gif then?
If you can stick to ImageMagick then it is very simple to solve this:
convert input.gif -coalesce output.png
Otherwise, you will have to consider the different forms of how each GIF frame can be constructed. For this specific type of GIF, and also the other one shown in your other question, the following code works (note that in your earlier question, the accepted answer doesn't actually make all the split parts transparent -- at least with the latest released PIL):
import sys
from PIL import Image, ImageSequence
img = Image.open(sys.argv[1])
pal = img.getpalette()
prev = img.convert('RGBA')
prev_dispose = True
for i, frame in enumerate(ImageSequence.Iterator(img)):
dispose = frame.dispose
if frame.tile:
x0, y0, x1, y1 = frame.tile[0][1]
if not frame.palette.dirty:
frame.putpalette(pal)
frame = frame.crop((x0, y0, x1, y1))
bbox = (x0, y0, x1, y1)
else:
bbox = None
if dispose is None:
prev.paste(frame, bbox, frame.convert('RGBA'))
prev.save('foo%02d.png' % i)
prev_dispose = False
else:
if prev_dispose:
prev = Image.new('RGBA', img.size, (0, 0, 0, 0))
out = prev.copy()
out.paste(frame, bbox, frame.convert('RGBA'))
out.save('foo%02d.png' % i)
Ultimately you will have to recreate what -coalesce does, since it is likely that the code above may not work with certain GIF images.
You should try keeping the whole history of frames in "background", instead of :
background = Image.new("RGB", size, (255,255,255))
background.paste( lastframe )
background.paste( im2 )
Just create the "background" once before the loop, then only paste() frame on it, it should work.
in a school project i would like to do the following step to have a watermaked image in matlab
extract the edges from an image
insert a mark on this edge
reconstruct the image
extract the mark
could some one give me a link to have a good idea how to do it or help me to do that?
thank you in advance
You want to add a watermark to an image? Why not just overlay the whole thing.
if you have an image
img = imread('myimage.jpg')
wm = imread('watermark.jpg')
You can just resize the watermark to the size of the image
wm_rs = imresize(wm, [size(img,1) size(img,2)], 'lanczos2');
img_wm(wm_rs ~= 0) = wm_rs; %This sets non-black pixels to be the watermark. (You'll have to slightly modify this for color images)
If you want to put it on the edges of the image, you can extract them like this
edges = edge(rgb2gray(img),'canny')
Then you can set the pixels where the edges exist to be watermark pixels
img_wm = img;
img_wm(edges ~= 0) = wm_rs(edges~=0);
Instead of direct assignment you can play around with using a mix of the img and wm_rs pixel values if you want transparency.
You'll probably have to adjust some of what I said to color images, but most should be the same.
Here, is a nice and simple example how you can embed watermarks using MATLAB (in the spatial domain): http://imageprocessingblog.com/digital-watermarking/
see example below(R2017b or later release):
% your params
img = imread('printedtext.png');
Transparency = 0.6;
fontColor = [1,1,1]; % RGB,range [0,1]
position = [700,200];
%% add watermark
mask = zeros(size(img),'like',img);
outimg = insertText(mask,position,'china', ...
'BoxOpacity',0,...
'FontSize',200,...
'TextColor', 'white');
bwMask = imbinarize(rgb2gray(outimg));
finalImg = labeloverlay(img,bwMask,...
'Transparency',Transparency,...
'Colormap',fontColor);
imshow(finalImg)
I would like to extract the most used colors inside an image, or at least the primary tones
Could you recommend me how can I start with this task? or point me to a similar code? I have being looking for it but no success.
You can get very good results using an Octree Color Quantization algorithm. Other quantization algorithms can be found on Wikipedia.
I agree with the comments - a programming solution would definitely need more information. But till then, assuming you'll obtain the RGB values of each pixel in your image, you should consider the HSV colorspace where the Hue can be said to represent the "tone" of each pixel. You can then use a histogram to identify the most used tones in your image.
Well, I assume you can access to each pixel RGB color. There are two ways you can so depending on how you want it.
First you may simply create some of all pixel's R, G and B. Like this.
A pseudo code.
int Red = 0;
int Green = 0;
int Blue = 0;
foreach (Pixels as aPixel) {
Red += aPixel.getRed();
Green += aPixel.getGreen();
Blue += aPixel.getBlue();
}
Then see which is more.
This give you only the picture is more red, green or blue.
Another way will give you static of combined color too (like orange) by simply create histogram of each RGB combination.
A pseudo code.
Map ColorCounts = new();
foreach (Pixels as aPixel) {
const aRGB = aPixel.getRGB();
var aCount = ColorCounts.get(aRGB);
aCount++;
ColorCounts.put(aRGB, aCount);
}
Then see which one has more count.
You may also reduce the color-resolution as a regular RGB coloring will give you up to 6.7 million colors.
This can be done easily by given the RGB to ranges of color. For example, let say, RGB is 8 step not 256.
A pseudo code.
function Reduce(Color) {
return (Color/32)*32; // 32 is 256/8 as for 8 ranges.
}
function ReduceRGB(RGB) {
return new RGB(Reduce(RGB.getRed()),Reduce(RGB.getGreen() Reduce(RGB.getBlue()));
}
Map ColorCounts = new();
foreach (Pixels as aPixel) {
const aRGB = ReduceRGB(aPixel.getRGB());
var aCount = ColorCounts.get(aRGB);
aCount++;
ColorCounts.put(aRGB, aCount);
}
Then you can see which range have the most count.
I hope these technique makes sense to you.