I want to generate shapes like the one following (image file e.g. PNG):
I'm looking for a c / c++ library which will allow me to realize the following algorithm:
The basic algorithm would be:
Make circle
Partition Circle randomly
Fill in one segement
Twirl whole shape (see link)
Save Image as PNG
Link: Twirl filter in Photoshop
I will accept the first answer which lists and links one library or more which is will enable me to implement the above algorithm with ease. The library should be light weight if possible.
The 'easiest' solution I can think of is to use the GraphicsMagick library - specifically, the Magick++ API. With a Magick::Image, you can use Drawable objects, flood-fills, and even a Image::swirl method. Saving as a PNG can be as simple as a call to Image::write("filename.png")
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I am trying to perform text image restoration and I can find no proper documentation on how to perform OMP or K-SVD in C++ using opencv.
I have over 1000 training images of different sizes so do I divide images into equal sized patches or resize all images? How do I construct the signal matrix X?
What other pre-processing steps are required for sparse coding? How to actually perform K-SVD on color images?
What data type is available in OpenCV for an image dictionary and how do I initialize the Dictionary D?
I have these very basic questions and have tried to use various libraries but they don't make the working very clear.
I found this code useful. This is the only implementation in opencv I have come across so far. I guess it uses a single image for dictionary learning whereas I have to use at least 1000 images. But it certainly provides a good guideline.
Im looking for a way to warp an image similar to how the liquify/IWarp tool works in Photoshop/Gimp.
I would like to use it to move a few points on an image to make it look wider than it was originally.
Anyone have any ideas on libraries that could be used to do this? I'm currently using OpenCV in the same project so if theres a way using that it would be easiest but I'm open to anything really
Thanks.
EDIT: Heres an example of what im looking to do http://i.imgur.com/wMOzq.png
All I've done there is pulled a few points out sideways and thats what im looking to do from inside my application
From this search 'image warp operator source c++' i get:
..... Added function 'CImg ::[get_]warp()' that can warp an image using a deformation .... Added function 'CImg ::save_cpp()' allowing to save an image directly as a C/C++ source code. ...
then CImg could do well for you.
OpenCV's remap can accomplish this. You only have to provide x and y displacement maps. I would suggest you can create the displacement map directly if you are clever, and this would be good for brush-stroke manipulation similar to Photoshop's liquify. The mesh warp and sparse point map approach is another option, but essentially computes the displacement map based on interpolation.
You may want to take a look at http://code.google.com/p/imgwarp-opencv/. This library seems to be exactly what you need: image warping based on a sparse grid.
Another option is, of course, generate displacements yourself and use cv::Remap() function of OpenCV.
I'd like to render a video (can be any format as long as it works) on top of a marker, but I am not sure how to do this. I am using Artoolkit for desktop-based AR and QCAR for mobile AR. Eventually I want to get it done for both systems, therefore I am preferably looking for a video-library that I could use on both platforms.
Basically I know the steps that have to be done:
- load video file
- extract image according to current time
- use image as texture
- apply marker's transformation matrix to textured rectangle
Which libraries could I use to achieve the first two steps?
Which libraries could I use to achieve the first two steps?
Take a look into the libavcodec library (you can start here), but take into account that it is quite complex.
I want to create a SVG image programmatically using preferably c++ from some image points. Can anyone help me with that?
simple-svg is a header only svg lib easy to use:
simple_svg_1.0.0
Here is an example how to use it: main_1.0.0.cpp
It is also hosted on GitHub.
You could check out LibBoard. I have no experience with it myself, so I can't vouch for its usefulness, but it does appear to be what you're looking for. I'm not sure how complicated your target image is going to be, but the website states:
For now, LibBoard can handle primitives like lines, rectangles,
triangles, polylines, circles, ellipses and text.
In future releases, bitmap insertion should be supported.
See the TODO file for a list of features that should be added in future releases.
So you'll have basic functionality from it, and you can probably mess around with the basic list of shapes to create some pretty complicated images.
I used GraphViz to do that, using 'dot' language, check it out.
I am looking for a method, software or library for simple image analysis.
The input image will be a white-colored background, and some random small black dots on it.
I need to generate a .txt file that represents these dots' coordinates. That is, if there are three dots in the image the output will be a text file that includes somehow a representation of three coordinates, (x1,y1), (x2,y2), and (x3,y3).
I have searched the web for hours and didn't find something appropriate, all I found was complex programs for image processing.
I've been told that it's easy to write code for this mission in MATLAB, but I'm unfamiliar with MATLAB.
Can this be done easily with C++, Java or C#?
Any good libraries?
It is quite simple in any language. Depending on the form of your input, you probably need to go over all of it (assuming it is a simple matrix - simply have two nested loops, one for the x coordinate and one for the y coordinate), whenever you encounter a black dot - simply output the current indexes which would be the x and y coordinates for the dot.
As to libraries, anything other than something to decode your input to the form of such a matrix (e.g. a JPEG decoder) would be overkill.
I don't think you would need image processing libraries for this kind of problem (somebody correct me if I am wrong) since these libraries may focus on image manipulation and not recognition. What you will need is a knowledge of the image format that you are supporting (how are they stored, how are they interpreted, etc) and basic C file system functions.
For example, if you are expecting a JPG file format you will simply calculate the padding for each scanline and reach each scan line one by one, and each pixel in the line one by one. You'd have to use two counters, one for the row and one for the column. If the pixel is simply not white, then you have your coordinate
This is something which should be very easy for you to do without any external software; something like
for(y in [0..height]) {
for(x in [0..width]) {
if(pixels[y][x].color == BLACK)
print("(%d, %d)", x, y);
}
}
would work.
The bitmap file format is quite easy to read.
http://en.wikipedia.org/wiki/BMP_file_format
You could just stream the bytes into an array using this info. I've written a few BMP readers; it is a trivial matter.
Also, although I cannot vouch for its ease of use as I've never used it before, I've heard that EasyBMP works fine too.
CImg library shold help you. From CImg FAQ:
1.1. What is the CImg Library ?
The CImg Library is an open-source C++ toolkit for image processing.
It mainly consists in a (big) single header file CImg.h providing a
set of C++ classes and functions that can be used in your own sources,
to load/save, manage/process and display generic images. It's actually
a very simple and pleasant toolkit for coding image processing stuffs
in C++ : Just include the header file CImg.h, and you are ready to
handle images in your C++ programs.