Imagine I have a rectangle say 400px x 300px. Then let’s say I want to load an image in that. All of this is very easy using Sytem.Drawing.DrawImage.
Rectangle http://img576.imageshack.us/img576/2363/rectangle.gif
But then I want to leave the left hand side as 300px but change the right hand side to 250 px. I can draw the box using 4 DrawLines but I don’t know how to squash the image into the new shape. I want the right hand side of the shape to be 250, the left size 300 and the top and bottom 400px.
Resized http://img85.imageshack.us/img85/3479/rectangle2.gif
I can’t use DrawImage as it expects the left and right sizes to be the same. Is there a way to manipulate the image into the new shape?
I've looked at other questions, but they only apply where the left and right hand side is equal.
Any thoughts on how to squash an image into a shape which did not have parallel sides?
(If it helps, I'm happy to sacrifice image quality to fit the right shape.)
Disclaimer: I work for Atalasoft.
Our DotImage product has a command called QuadrilateralWarpCommand that can do this. It's in DotImage Photo.
What you want to do is non-trivial (but also very powerful).
#Heinzi is correct, the general class is called warp transformations. What you're trying to do is specifically a perspective transformation. At a high level, it involves running the individual coordinates through a transformation matrix to get their new positions, and then doing interpolation between pixel values based on the old and new locations.
This article talks about some transformations, one of them being a sheer, so it might be helpful overall. I'm not sure, I haven't read it closely. In general, you want to google for something approximately like "c# image transformation" or "c# image perspective transform".
Depending on what you're planning on using it for, buying a library might be the best way to go about it, although there is a lot to learn about image manipulation by doing it yourself.
I did not find a solution to your problem, but I have some information which might help you along:
What you want is called a warp transformation.
As far as I know, the .net framework natively supports this kind of transformation only for a GraphicsPath, namely, the GraphicsPath.Warp method. Unfortunately, I don't think that this will help you, unless you are willing to redraw your image using a .net GraphicsPath object.
If you need the transformation directly in the UI layer, your UI library might help: Silverlight, for example, includes the PlaneProjection class, which can be used for such effects; in WPF, the 3D engine might be useful for this (requiring more programming effort, through).
Related
Is there any way to build an image map with qml (qt quick) components directly without importing html code?And I want to it's coordinates be same as html imagemap's coordinates(I dont want to recalculate my image map coords).
and
my shape is rectangular.tnx
No, there is no way. MouseAreas are always rectangular.
You would need to provide a some kind of collision detection function, to check whether your click happened inside of your object, described by the coordinates.
For this you can implement any of the algorithmns out there, in a way, that it supports your coordinate format. The right choice depends on the characteristics of your objects, like:
Is it a circle?
Is it a regular shape?
Is it convex?
Is it concave?
There are many good pages on collision detection, though a performant implementation might be tricky - especially in QtQuicks JS, so you probably want to do it in C++.
Another shot you might take, is dropping your coordinates, and produce masks that can be used with the solution provided here: https://stackoverflow.com/a/38177820/2056452 (coming from an official example)
I am working with kinect in openframework using the ofxKinect addon, which is great and plenty fun!
Anyway I am looking for some pointers or a direction when dealing with multiple bodies on the screen. I was thinking of making a rect around each detected body and when the rects intersect something could happen, an effect or anything.
So what I am looking for are ideas or something that could point me to the right direction of detecting multiple bodies when using a kinect.
Right now based on the depth image I get from the kinect I go through each pixel and create a bunch of smaller rectangles with a padding and group them in a larger rectangle bound if they are separate from another rectangle group. This is not ideal as it only deals with the pixel values and is not really seperating bodies from eachother and is not giving me the results I am looking for.
So any ideas would be greatly appreciated!
If you want to use ofxKinect a quick solution would be to threshold on depth and assume bodies and no other objects will be within a depth range. This should make it easy to use the OpenCV's contour finder to isolate the outlines of the bodies and get the bounding rectangles. If the rectangles intersect(and ofRectangle already does the math you), trigger the reaction you need. Also don't forget to do that once if the effect isn't showing already, otherwise you will trigger the effect multiple times per second while the two bodies' bounding rectangles intersect.
You could try something a bit more hardcore and using ofxCv(not just ofxOpenCV) to tap into the HoG functionality. This is slow in itself and not ideal with the depth map, but hopefully you can run in every few seconds just to detect a person and the depth, then keep tracking that movement.
Personally, if you want to track people with the Kinect I recommend using ofxOpenNI as if already provides the scene segmentation feature and even if you don't track the skeletons you can still get useful information like the pixels pertaining to each body and they're centre of mass. I'm guessing Microsoft KinectSDK has a similar feature and there should be an oF addon, but it's windows only.
ofxKinect/libfreenect does not offer any people detection features, so you will need to roll your own.
In iOS, I'd like to have a series of items in "space" similar to the way Time Machine works. The "space" would be navigated by a scroll bar like feature on the side of the page. So if the person scrolls up, it would essentially zoom in in the space and objects that were further away will be closer to the reference point. If one zooms out, then those objects will fade into the back and whatever is behind the frame of refrence will come into view. Kind of like this.
I'm open to a variety of solutions. I imagine there's a relatively easy solution within openGL, I just don't know where to begin.
Check out Nick Lockwood's iCarousel on github. It's a very good component. The example code he provides uses a custom carousel style very much like what you describe. You should get there with just a few tweaks.
As you said, in OpenGL(ES) is relatively easy to accomplish what you ask, however it may not be equally easy to explain it to someone that is not confident with OpenGL :)
First of all, I may suggest you to take a look at The Red Book, the reference guide to OpenGL, or at the OpenGL Wiki.
To begin, you may do some practice using GLUT; it will help you taking confidence with OpenGL, providing some high-level API that will let you skip the boring side of setting up an OpenGL context, letting you go directly to the drawing part.
OpenGL ES is a subset of OpenGL, so essentially has the same structure. Once you understood how to use OpenGL shouldn't be so difficult to use OpenGL ES. Of course Apple documentation is a very important resource.
Now that you know a lot of stuff about OpenGL you should be able to easily understand how your program should be structured.
You may, for example, keep your view point fixed and translate the world (or viceversa). There is not (of course) a universal solution, especially because the only thing that matters is the final result.
Another solution (maybe equally good, it depends on your needs), may be to simply scale up and down images (representing the objects of your world) to simulate the movement through the object itself.
For example you may use an array to store all of your images and use a slider to set (increase/decrease) the dimension of your image. Once the image becomes too large for the display you may gradually decrease alpha, so that the image behind will slowly appear. Take a look at UIImageView reference, it contains all the API's you need for it.
This may lead you to the loss of 3-dimensionality, but it's probably a simpler/faster solution than learn OpenGL.
I'm completely new to ArcGIS and ArcMap, but someone suggested this program to me for a project I'm working on.
I would like to animate individual entities on a map, and was wondering if it is possible to do so in ArcMap. I asked this earlier here and a member directed me to a tutorial on animating in ArcGIS. The animation in the guide was over a map spread (ie. each pixel on the map displays, say, a different color to indicate population data in the area). However I realized that if I zoom in a lot, eventually the image will degenerate into pixels, which is why I need an actual object to mark a certain point. I checked some online tutorials and it seems like we can place markers on the map. Can someone tell me if it is possible to animate these markers (for example via a for-loop)? And if so, could you point me in a direction where to start?
Thanks in advance!
You can animate layers in ArcMap is the short answer. Its not as simple as using the timeline feature in Google Earth for example though. But then ArcMap is much more than just a visualization tool.
This help page on the ESRI web help looks like a good place to start.
I'm not 100% sure what you mean by the image degenerates into pixels. Are you saying that the markers were single points in the layer. Unlike Google Earth you are not confined to simply plotting points on the map. You can draw completely arbitrary shapes in ArcMap, which can be defined to cover actual areas of the map, so when you zoom-in the shape gets larger.
The way you need to load data into ArcMap to produce an animation isn't too simple. There might be other ways to do this, but the way I know of is to generate a NetCDF file. This file contains a 3D matrix of layer data, where each layer is separated through time. Because you generate a matrix, you are effectively placing a raster image over the map. Thus if you want to cover a large area, each matrix becomes large, and you multiply that by the number of time slices you wish to animate over.
Once you have a NetCDF file with your data in however, getting ArcMap to animate it and produce say a .avi file is pretty simple.
You could try just loading some of the example NetCDF datasets into ArcMap to see how/if they will work to get you started.
Hope that helps.
The upcoming v10 will have better time-aware capabilities, which will allow for animation.
If i wanted to crop an image in VB.net, how would I go about doing it? I am trying to let the user drag out the box they want (system.drawing.rectangle), and it will automatically remove the edges surrounding the box.
My first problem is primarily the fact that I cannot make the system.drawing.rectangle visible. It is not displaying at all, I am setting its location and height programmatically, but nothing is showing up. I know there is probably something fairly obvious I am missing...but I cannot seem to find it.
My larger issue, however, lies with the cropping itself. I cannot find any crop methods, at all. Is there a hidden one I am missing? Or must I code it myself? How would I go about doing this? It ought to be able to output to a bitmap image object.
Thanks for the help, I am surprised this hasn't been asked on here before....
Regarding your first problem: a Rectangle isn't by itself visible. You have to draw it on your canvas using the Graphics object's DrawRectangle(...) method. For drawing a selection tool, you'll want to set your Pen object's DashCap and DashPattern properties.
To "crop" an image, you basically want to take the portion of a larger image delineated by a smaller Rectangle, and turn it into a new Bitmap. This can be done using one of the 30 overloads of the Graphics object's DrawImage(...) method. You can either keep the cropped portion in its original dimensions (resulting in a smaller Bitmap than your original), or you can "blow it up" to something like the original image's size. If you do the latter approach, it is usually a good idea to set your Graphics object's InterpolationMode property to HighQualityBicubic (I think that's the one, anyway), since the default InterpolationMode is pretty crappy.
There are a number of different ways of rendering images in .Net - it might help if you posted some of your code, along with an explanation of the exact problems you're running into.
Here is another answer with a link to a sample app (and source code in C#, sorry) that may help you get started.
There are a number of articles on these topics on CodeProject:
Pick your favorite flavor (though I encourage you to check out the C# projects - it shouldn't be too hard to convert).
VB
Image Cropping with Image Resizing Using vb.net
C#
Cropping Images
An Easy to Use Image Resizing and Cropping Control
Image Processing using C# (see the Cropping section - I was able to use this code in one of my projects)
WPF/C#
WPF Interactive Image Cropping Control
A Photoshop-like Cropping Adorner for WPF