image-processing

Noise Estimation / Noise Measurement in Image

Hello. I want to estimate the noise in an image. Let's assume the model of an Image + White Noise. Now I want to estimate the Noise Variance. My method is to calculate the Local Variance (3*3 up to 21*21 Blocks) of the image and then find areas where the Local Variance is fairly constant (By calculating the Local Variance of the Local ...

Basic image resizing in Ruby on Rails

I'm creating a little photo sharing site for our home's intranet, and I have an upload feature, which uploads the photo at original size into the database. However, I also want to save the photo in four other sizes: W=1024, W=512, W=256 and W=128, but only the sizes smaller than the original size (e.g. if the original width is 511, only ...

What scripting language would you use to put text over a generated image ?

I got this question from my cousin: "What will be the best way to create a similar working website just like: http://www.plakletters.nl". I have looked into the website and think that to start of with i'm gonna help my cousin write a script that loads all fonts installed on the system into a dropdownlist. This dropdownlist will post a...

Skewing an image using Perspective Transforms

I'm trying to perform a skew on an image, like one shown here . I have an array of pixels representing my image and am unsure of what to do with them. ...

programmatically trimming (automatically cropping out transparent boundaries) an image in objective-c / cocoa

Does anyone know how to trim an image (uiimage or cgimage). By trim I mean programatically cropping to the non-transparent bounds of an image. So if I have the image below: 00111000 00010000 01011110 00000000 it would yield: 011100 001000 101111 ...

find the colour name from a hexadecimal colour code

Hi , i want to find the name of a colour from the hexadecimal colour code. When i get a hex colour code i want to find the most matching colour name. for example for the code #c06040 , how to find out if it is a shade of brown, blue or yellow ?. so that i can find the colour of an object in the image without human intervention. Is the...

wordpress image uploads

I have created my own upload function for forms on my sites frontend. the images upload correctly, but in some cases a blank reference to the image with this as its path: /USR/WWW/USERS//WP-CONTENT/BLOGS.DIR/2/FILES/ occurs in the media library. its seems as though the form uploads images but where there is no image to upload a blank re...

Android Image Problem and threshold

Hey Guys, Long time reader never posted until now. Im having some trouble with Android, im implementing a library called JJIL its an open source imaging library. My problem is this i need to run some analysis on an image and to do so i need to have it in jjil.core.image format and once those processes are complete i need to convert th...

MATLAB: image corner coordinates & referncing to cell arrays

I am having some problems comparing the elements in different cell arrays. The context of this problem is that I am using the bwboundaries function in MATLAB to trace the outline of an image. The image is of a structural cross section and I am trying to find if there is continuity throughout the section (i.e. there is only one outline ...

Dynamically create and save image with Django and PIL/Django-Photologue

I want to generate a page of html with dynamic content and then save the result as an image as well as display the page to the user. So, user signs up to attend conference and gives their name and org. That data is combined with html/css elements to show what their id badge for the conference will look like (their name and org on top of ...

Implemeting "drawing modes" in a graphics library?

i would like to implement 'drawing modes' (in my own graphics library). That is drawing with AND, OR, etc However i am storing colors using floats, each channel between 0 and 1.0 Do i have to first convert each color channel to 0-255 before i can use the AND, OR, etc drawing modes? and then convert back to float (0.0-1.0) ? Or is there...

How to store thumbnail image into the database?

I created an .png image from a video using ffmpeg tool and i want to how to insert that image into the db which has a blob field and also i want to know how can i recollect that image from the db to display as a image again? ...

How to find one image inside of another?

I have 2 bmp images. ImageA is a screenshot (example) ImageB is a subset of that. Say for example, an icon. I want to find the X,Y coordinates of ImageB within ImageA (if it exists). Any idea how I would do that? ...

Resizing Images with ASP.NET and saving to Database

I need to take an uploaded image, resize it, and save it to the database. Simple enough, except I don't have access to save any temp files to the server. I'm taking the image, resizing it as a Bitmap, and need to save it to a database field as the original image type (JPG for example). How can I get the FileBytes() like this, so I can...

Copy Small Bitmaps on to Large Bitmap with Transparency Blend: What is faster than graphics.DrawImage(smallBitmap, x , y) ?

I have identified this call as a bottleneck in a high pressure function. graphics.DrawImage(smallBitmap, x , y); Is there a faster way to blend small semi transparent bitmaps into a larger semi transparent one? Example Usage: XY[] locations = GetLocs(); Bitmap[] bitmaps = GetBmps(); //small images sizes vary approx 30px x 30px...

Scaling larger Image problem.

Hi, I m developing flex application, in which I want to Draw Image from User local hard-drive to the canvas of size 640x360. User can choose Image of bigger resolution & is scaled to Canvas size. But if user selected images of larger resolution like 3000x2000, the scaling take lot time & freezes the application until scale done. Is t...

Java: Line appears when using AffineTransform to scale image

Hi, I'm having a problem with image scaling. When I use the following code to scale an image it ends up with a line either at the bottom or on the right side of the image. double scale = 1; if (scaleHeight >= scaleWidth) { scale = scaleWidth; } else { scale = scaleHeight; } AffineTransform af = new AffineTransform(); af.scale(s...

uneven illuminated images

How to get rid of uneven illumination from images, that contain text data, usually printed but may be handwritten? It can have some spots of lights because the light reflected while making picture. I've seen the Halcon program's segment_characters function that is doing this work perfectly, but it is not open source. I wish to convert a...

Detect Rotation of a scanned image in C#

We want a c# solution to correct the scanned image because it is rotated. To solve this problem we must detect the rotation angle first and then rotate the image. This was our first thought for our problem. But then we thought image warping would be more accurate as I think it would make the scanned image like our template. Then we can p...

How can I overlay one image onto another?

I would like to display an image composed of two images. I want image rectangle.png to show with image sticker.png on top of it with its left-hand corner at pixel 10, 10. Here is as far as I got, but how do I combine the images? Image image = new Image(); image.Source = new BitmapImage(new Uri(@"c:\test\rectangle.png")); image.Stretch...