image-processing

How do you composite an image onto another image with PIL in Python?

I need to take an image and place it onto a new, generated white background in order for it to be converted into a downloadable desktop wallpaper. So the process would go: 1) Generate new, all white image with 1440x900 dimensions 2) Place existing image on top, centered 3) Save as single image In PIL, I see the ImageDraw object, but no...

What's the significant difference between these two image processing libs of c/c++?

OpenCV GIL Is there some experienced user can share it? I need to know the difference to decide which to choose. ...

matrix image processing in OpenGL CE

im trying to create an image filter in OpenGL CE. currently I am trying to create a series of 4x4 matrices and multiply them together. then use glColorMask and glColor4f to adjust the image accordingly. I've been able to integrate hue rotation, saturation, and brightness. but i am having trouble adding contrast. thus far google hasn't be...

GD! Converting a png image to jpeg and making the alpha by default white and not black.

I tried something like this but it just makes the background of the image white, not necessarily the alpha of the image. I wanted to just upload everything as jpg's so if i could somehow "flatten" a png image with some transparently to default it to just be white so i can use it as a jpg instead. Appreciate any help. Thanks. $old = imag...

Serverside image processing

I am designing a web application that does server side image processing in real time. Processing tasks include applying different effects like grayscale, blur, oil paint, pencil sketch etc on images in various formats. I want to build it using java/servlets which I am already familiar with. I found 3 options, 1) Use pure java imaging li...

Image Recognition (Shape recognition)

I want to recognize the shapes in the picture by template matching.Is the "ExhaustiveTemplateMatching" is the right option given in Aforge.Net for this purpose.Had anyone tried this class and find it working correctly.How accurate and right choice this class is for achieving my purpose.Suggest any other methods or Alogrithms as well for ...

image processing problem

i'm working on detecting shape of any object.i've a binary image where background is white pixels and foreground/object is black pixel. now i need to detect the shape of the area where there are black pixels.how can i do it?the shape may be of a man/car/box etc. plz help ...

Question on multi-probe Local Sensitive Hashing

Hey guys sorry to be asking this kind noob question, but because I really need some guidance on how to use Multi probe LSH pretty urgently, so I did not do much research myself. I realize there is a lib call LSHKIT available that implemented that algorithm, but I have trouble trying to figure out how to use it. Right now, I have a few ...

Why can fourier transform be used for image recognization while being sensitive to noises?

As we know Fourier Transform is sensitive to noises(like salt and peppers), how can it still be used for image recognization? Is there a FT expert here? ...

Bandpass filter of FFT applied image. (Like ImageJ bandpass filter algorithm)

There is a good function that I need, which is implemented in Java program: ImageJ I need to understand the algorithm used there. The function has several parameters: link text And before using FFT it converts image to a special one: The Bandpass Filter uses a special algorithm to reduce edge artifacts (before the Fourier transform, th...

3D effect to distort paper

This may be a little hard to describe since I don't have a sample. I'm trying to find a math function or full 3d function in php or a similar language that can help me with the following effect: imagine if you were to take a flat sheet or paper and glue it on a glass of water. It wouldn't be flat any more. It would have a curve, and on...

How do I use graythresh on an indexed image in MATLAB?

I = imread('coins.png'); level = graythresh(I); BW = im2bw(I,level); imshow(BW) The above is an example from the MATLAB documentation using a grayscale image. How can I make it work with an indexed image like in this post? ...

Why does this code read all ' ' for the anything after the 4th character?

#define fileSize 100000 int main(int argc, char *argv[]){ char *name=argv[1]; char ret[fileSize]; FILE *fl = fopen(name, "rb"); fseek(fl, 0, SEEK_END); long len = fileSize; fseek(fl, 0, SEEK_SET); //fread(ret, 1, len, fl); int i; *(ret+fileSize) = '\0'; ...

How can I implement this visual effect in MATLAB?

One can use Google's logo for a try: BTW, what's the term for it? ...

Aligning multiple images into one image?

What is a good method to align images together that may have different rotations, exposures, etc, but have the same background or other fixed reference? Adobe Photoshop can do this with its "Photomerge" feature. How can I do this programatically? Is there an Open Source application that does it? ...

How can I create a JAI PlanarImage from a byte array raster?

I have an application that uses JAI to process images. It takes TIFF files, reads them, wraps the content into a SeekableStream then uses JAI.create to create the PlanarImage. What I want to do is change the source from TIFF files to a component, which already exists, and which serves me the image data in the form of a raster stored in ...

Text detection of image

I got grayscale images made by cheap camera and I need to make a program OCR. The main problem is noise or objects that are not text but they present in binary image. Now I think of text extraction from image. I need some good algorithm for that. Can you suggest any really good one? For example if image contains black color text and so...

Image processing with barehands-ruby

I want to know how to open and manipulate a simple image file in Ruby language. I don't need to do any advanced stuff, just things like open(), get_pixel() and put_pixel() and I don't wanna use any gem for doing that, but just to know the barehands-ruby way. ...

Is there any super fast algorithm for finding LINES on picture?

So I have Image like this I want to get something like this (I hevent drawn all lines I want but I hope you can get my idea) I need some super fast algorithm for finding all straight lines on it. I want to give to algorithm parameters like min length and max line distortion. I want to get relative to picture pixel coords start and...

How to do a fadein of an image on an Android Activity screen?

I'd like to display a photo on an Android Activity screen with doing gradual and continual fade-in from pale monotone sepia to the final full color. I know how to do it on a Java Image/BufferedImage for the Graphic object but unfortunately I know nothing for the Android programming environment. Could anyone help? ...