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I am desperately searching for a good cropping tool. There are a bunch out there, for example:
Croppic
Cropit
Jcrop
The most important thing that I am trying to find is a cropping tool, that crops images without making the cropped image low in resolution. You can hack this by using the canvas tag by resizing the image. This way the image itself stays native, only the representation is smaller.
DarkroomJS was also something near the solution, but, unfortunately, the downloaded demo did not work. I'll try to figure out whats wrong. Does someone know some great alternatives, or how to get the cropped images in...let's say "native" resolution?
Thanks in advance!
You are relying on the cropping tool to provide an interface for the users. the problem is that the image returned is sized to the interface and not the original image. Rather than me sifting through the various API's to see if they provide some way of controlling this behaviour (I assume at least some of them would) and because it is such a simple procedure I will show how to crop the image manually.
To use JCrop as an example
Jcrop provides various events for cropstart, cropmove, cropend... You can add a listener to listen to these events and keep a copy of the current cropping interface state
var currentCrop;
jQuery('#target').on('cropstart cropmove cropend',function(e,s,crop){
currentCrop = crop;
}
I don't know where you have set the interface size and I am assuming the events return the crop details at the interface scale
var interfaceSize = { //you will have to work this out
w : ?,
h : ?.
}
Your original image
var myImage = new Image(); // Assume you know how to load
So when the crop button is clicked you can create the new image by scaling the crop details back to the original image size, creating a canvas at the cropped size, drawing the image so that the cropped area is corectly positioned and returning the canvas as is or as a new image.
// image = image to crop
// crop = the current cropping region
// interfaceSize = the size of the full image in the interface
// returns a new cropped image at full res
function myCrop(image,crop,interfaceSize){
var scaleX = image.width / interfaceSize.w; // get x scale
var scaleY = image.height / interfaceSize.h; // get y scale
// get full res crop region. rounding to pixels
var x = Math.round(crop.x * scaleX);
var y = Math.round(crop.y * scaleY);
var w = Math.round(crop.w * scaleX);
var h = Math.round(crop.h * scaleY);
// Assume crop will never pad
// create an drawable image
var croppedImage = document.createElement("canvas");
croppedImage.width = w;
croppedImage.height = h;
var ctx = croppedImage.getContext("2d");
// draw the image offset so the it is correctly cropped
ctx.drawImage(image,-x,-y);
return croppedImage
}
You then only need to call this function when the crop button is clicked
var croppedImage;
myButtonElement.onclick = function(){
if(currentCrop !== undefined){ // ensure that there is a selected crop
croppedImage = myCrop(myImage,currentCrop,interfaceSize);
}
}
You can convert the image to a dataURL for download, and upload via
imageData = croppedImage.toDataURL(mimeType,quality) // quality is optional and only for "image/jpeg" images
I have a 3 dimension matrix of data (a stack of images across a dimension, time for example.
I want to display an image, and have a slider below to navigate across the images.
I wrote a piece of code which works, but it's bulky and kinda ugly I think...I want to write a clean function and so I would like to know if anyone know of a cleaner, nicer way to do it.
Here is my code:
interv = [min max]; % interval for image visualization
imagesc(Temps_visu,X*100,squeeze(X,Y,MyMatrix(:,:,1)),interv);
title('My Title');
xlabel('X (cm)');
ylabel('Y (cm)');
pos = get(gca,'position');
% slider position
Newpos = [pos(1) pos(2)-0.1 pos(3) 0.05];
pp = 1;
% callback slider
S = ['pp=floor(get(gcbo,''value''));imagesc(Temps_visu,X*100,squeeze(X,Y,MyMatrix(:,:,1)),interv));' ...
'set_axes_elasto;title(''My Title'');disp(pp);'];
Mz = size(MyMatrix,3);
% Creating Uicontrol
h = uicontrol('style','slider',...
'units','normalized',...
'position',Newpos,...
'callback',S,...
'min',1,'max',Mz,...
'value',pp,...
'sliderstep',[1/(Mz-1) 10/(Mz-1)]);
Here is a way to do it using a listener object for smooth visualization of your stack. I made up a dummy stack using grayscale variations of the same image (i.e. only 4 frames) but the principle will be the same for your application. Notice that I use imshow to display the images, but using imagesc as you do won't cause any problem.
The code is commented so hopefully this is clear enough. If not please don't hesitate to ask for help!
Code:
function SliderDemo
clc
clear all
NumFrames = 4; %// Check below for dummy 4D matrix/image sequence
hFig = figure('Position',[100 100 500 500],'Units','normalized');
handles.axes1 = axes('Units','normalized','Position',[.2 .2 .6 .6]);
%// Create slider and listener object for smooth visualization
handles.SliderFrame = uicontrol('Style','slider','Position',[60 20 400 50],'Min',1,'Max',NumFrames,'Value',1,'SliderStep',[1/NumFrames 2/NumFrames],'Callback',#XSliderCallback);
handles.SliderxListener = addlistener(handles.SliderFrame,'Value','PostSet',#(s,e) XListenerCallBack);
handles.Text1 = uicontrol('Style','Text','Position',[180 420 60 30],'String','Current frame');
handles.Edit1 = uicontrol('Style','Edit','Position',[250 420 100 30],'String','1');
%// Create dummy image sequence, here 4D sequence of grayscale images.
MyImage = imread('peppers.png');
MyMatrix = cat(4,rgb2gray(MyImage),MyImage(:,:,1),MyImage(:,:,2),MyImage(:,:,3));
%// Use setappdata to store the image stack and in callbacks, use getappdata to retrieve it and use it. Check the docs for the calling syntax.
setappdata(hFig,'MyMatrix',MyMatrix); %// You could use %//setappdata(0,'MyMatrix',MyMatrix) to store in the base workspace.
%// Display 1st frame
imshow(MyMatrix(:,:,:,1))
%// IMPORTANT. Update handles structure.
guidata(hFig,handles);
%// Listener callback, executed when you drag the slider.
function XListenerCallBack
%// Retrieve handles structure. Used to let MATLAB recognize the
%// edit box, slider and all UI components.
handles = guidata(gcf);
%// Here retrieve MyMatrix using getappdata.
MyMatrix = getappdata(hFig,'MyMatrix');
%// Get current frame
CurrentFrame = round((get(handles.SliderFrame,'Value')));
set(handles.Edit1,'String',num2str(CurrentFrame));
%// Display appropriate frame.
imshow(MyMatrix(:,:,:,CurrentFrame),'Parent',handles.axes1);
guidata(hFig,handles);
end
%// Slider callback; executed when the slider is release or you press
%// the arrows.
function XSliderCallback(~,~)
handles = guidata(gcf);
%// Here retrieve MyMatrix using getappdata.
MyMatrix = getappdata(hFig,'MyMatrix');
CurrentFrame = round((get(handles.SliderFrame,'Value')));
set(handles.Edit1,'String',num2str(CurrentFrame));
imshow(MyMatrix(:,:,:,CurrentFrame),'Parent',handles.axes1);
guidata(hFig,handles);
end
end
The figure looks like this:
Hope that helps!
from PIL import Image
import sys
image = Image.open(sys.argv[1])
basewidth = 1200
img = image
wpercent = (basewidth / float(img.size[0]))
hsize = int((float(img.size[1]) * float(wpercent)))
img = img.resize((basewidth, hsize), Image.BICUBIC)
img.save('sompic1.jpg')
print "image to %s" % (str(img.size))
i want to resize 1200xauto and this without losing any ratio so the image must keep its shartness etc etc.
but resized images are somehow destroyed in sharpness. I used ANTIALIAS also, but no change. how is it possible not to lose the sharpness?
original image: (600x450)
new one (1200x630):
You are trying to resize an image to a larger size than the original, it is normal that you loose quality.
To resize you image to a smaller size, you may have a look at this module I created: python-image-resize
I am writing a function that generates a movie mimicking a particle in a fluid. The movie is coloured and I would like to generate a grayscaled movie for the start. Right now I am using avifile instead of videowriter. Any help on changing this code to get grayscale movie? Thanks in advance.
close all;
clear variables;
colormap('gray');
vidObj=avifile('movie.avi');
for i=1:N
[nx,ny]=coordinates(Lx,Ly,Nx,Ny,[x(i),-y(i)]);
[xf,yf]=ndgrid(nx,ny);
zf=zeros(size(xf))+z(i);
% generate a frame here
[E,H]=nfmie(an,bn,xf,yf,zf,rad,ns,nm,lambda,tf_flag,cc_flag);
Ecc=sqrt(real(E(:,:,1)).^2+real(E(:,:,2)).^2+real(E(:,:,3)).^2+imag(E(:,:,1)).^2+imag(E(:,:,2)).^2+imag(E(:,:,3)).^2);
clf
imagesc(nx/rad,ny/rad,Ecc);
writetif(Ecc,i);
if i==1
cl=caxis;
else
caxis(cl)
end
axis image;
axis off;
frame=getframe(gca);
cdata_size = size(frame.cdata);
data = uint8(zeros(ceil(cdata_size(1)/4)*4,ceil(cdata_size(2)/4)*4,3));
data(1:cdata_size(1),1:cdata_size(2),1:cdata_size(3)) = [frame.cdata];
frame.cdata = data;
vidObj = addframe(vidObj,frame);
end
vidObj = close(vidObj);
For your frame data, use rgb2gray to convert a colour frame into its grayscale counterpart. As such, change this line:
data(1:cdata_size(1),1:cdata_size(2),1:cdata_size(3)) = [frame.cdata];
To these two lines:
frameGray = rgb2gray(frame.cdata);
data(1:cdata_size(1),1:cdata_size(2),1:cdata_size(3)) = ...
cat(3,frameGray,frameGray,frameGray);
The first line of the new code will convert your colour frame into a single channel grayscale image. In colour, grayscale images have all of the same values for all of the channels, which is why for the second line, cat(3,frameGray,frameGray,frameGray); is being called. This stacks three copies of the grayscale image on top of each other as a 3D matrix and you can then write this frame to your file.
You need to do this stacking because when writing a frame to file using VideoWriter, the frame must be colour (a.k.a. a 3D matrix). As such, the only workaround you have if you want to write a grayscale frame to the file is to replicate the grayscale image into each of the red, green and blue channels to create its colour equivalent.
BTW, cdata_size(3) will always be 3, as getframe's cdata structure always returns a 3D matrix.
Good luck!
I'm looking for how can I display an image in my GUI in a specific region of my interface.
In GUIDE, you can draw axes into the GUI. Then, in a callback function, you can plot an image into the axes.
Personally, I would rather not have the image inside the GUI, because it makes it harder to resize everything properly, and if you want to have a closer look at the image, or capture it to paste into another application, having the figure as part of the GUI can be inconvenient. Thus, I prefer to have the image open in a separate figure window.
Try the following code:
function movingimage
%# Plotting a figure
fig1=figure('Name','Plotting an image',...
'Unit','normalized', 'Position',[.1 .1 .8 .8]);
uicontrol(fig1,'Style','text','Unit','Normalized',...
'Position',[.9 .85 .1 .07],'String','Press the button below to move the image location.');
uicontrol(fig1,'Style','pushbutton','Unit','Normalized',...
'Position',[.9 .8 .05 .05],'String','Move','Callback',{#action_Callback});
%# Say, you wish to plot an image of relative dimension (.3 x .3) to the figure.
xdim=.3; ydim=.3;
%# Image's movable range in x is (1 - xdim)
dx=1-xdim;
%# Image's Movable range in y is (1 - ydim)
dy=1-ydim;
%# considering the size of the image...
pos = [.5*dx .5*dy xdim ydim]; %# Initial location of the image is at the center of the figure.
ax1 = axes('position',pos);
img = load('mandrill');
image(img.X)
colormap(img.map);axis off;axis equal;
function action_Callback(hObj,eventdata)
pos=[rand(1)*dx rand(1)*dy xdim ydim];
set(ax1,'position',pos);
end
end
The most direct and easy way I find to do this is to use the Axis component as shown in this tutorial:
http://www.aboutcodes.com/2012/06/how-to-display-image-in-gui-using.html