I want to generate some QR Code with a bigger background view, does somebody know is there an open source project can directly generate this image or can add background view to my completed QR code. Thanks a lot!
Libraries generate a matrix, not an image. Some do make JPEGs, but I don't think you can specifiy the size of the background.
The border you're talking about is the quietzone, it should be 4 modules wide. Denso Wave used to indicate that in its website but I can't find much more that this: https://www.denso-wave.com/en/adcd/QRdeCODE/product.html. Yet, the specifications are clear about it.
You could use a library such as ZXing or QrCode.net and make the image yourself.
You can find many more information on this QR Code White Book.
Related
I'm trying to create an objective C classe for my iPad application which can convert a powerpoint file to a jpeg file.
Accordingly i've to read into the pptx format to see how the file is structured and create an image, from scratch, in which i can say this element goes there, this one here, this text there.
But actually i've no idea how to do this, if the best way is to use a already existing framework in iOS or an additional library?
Thanks to everyone ;)
Bye
The fastest way to visualize elements is, to me, OpenGL ES. You can use mobile GPU to visualize then there is CIImage for managing image.
Take a look at Quartz 2D, the drawing engine used as the main workhorse for 2D graphics on iOS. It gives you all the primitives for drawing shapes, fills, text and other objects you need to render the presentation.
I'm following this guide: http://www.aishack.in/2010/08/sudoku-grabber-with-opencv/2/
and modifying to iOS 5.0.
I managed to find the largest contour (the sudoku "board"), however, it only locates the surrounding square, without the lines inside, as in the tutorial. can this be easily solved?
I'll try and find a way around it, but still would like to know. thanks!
I assume that you are using the camera right now. Try to load the image what is used in the tutorial and check if your implementation works on that image. Then you can continue with nice sudoku images from the web. You may also change the camera angle and distance from the sudoku when taking pictures to get a better, clearer view.
I'm basically trying to work out how to take a slice of an image, say a screenshot of an iPhone home screen, slice out the first icon and compare it to a set array of images in a library. Any help on where to start?
I'm no iPhone programmer, but I might be able to suggest a few things:
The SURF feature detection implemented in OpenCV should help you with this
There is a nice article on using OpenCV in Objective-C code.
A quick & dirty way might be to use the difference blend mode which should return the difference between the 1st image(top) and the 2nd image(bottom). If there is no difference the result will be completely black. So, the more black pixels in the difference result, potentially, the more similarities between the compared images.
I'm not an iOS developer, so I don't know if there is an image library that ships with sdk or if there's a free/opensource library for basic image processing. Still this should be trivial to implement:
e.g.
- (int)difference((int)topPixel,(int)bottomPixel)
{
return abs(topPixel-bottomPixel);
}
Note: Syntax might not be correct :)
HTH
This may not help you with taking a screenshot of the iOS home screen... But these articles show how to take snapshots from within a UIKit application:
https://developer.apple.com/library/prerelease/ios/#qa/qa1703/_index.html
https://developer.apple.com/library/prerelease/ios/#qa/qa1714/_index.html
Perhaps you would instruct the user to press home-power (buttons) to take a snapshot and store in the photo roll, then load that screenshot into an app to process the screenshot.
Hope this helps!
I have a one spritesheet image with all sprites, I downloaded this image from Interent. My question: Is there a tool that help me to get the coordinates of each sprite? would I have to search coordinates manually ?
I've been reading several tutorials like:http://www.raywenderlich.com/1271/how-to-use-animations-and-sprite-sheets-in-cocos2d and http://indiedevstories.com/2011/04/10/using-sprite-sheets-in-cocos2d-and-tiled-part-1/, but all them use multiple images to create one spritesheet and generate automatically the .plist, but this is not my case.
In my case I have only one .png and no .plist
Help me please!!!
Apologies for the self-promotion but I have created a tool for working with single spritesheet images and outputting the coordinates. It even has automatic sprite selection :)
http://www.darkfunction.com/editor
You can crop the images using some editor (photoshop for example) and then use the exiting tool to generate the texture and the plist. I think it will be the fastest and the easiest way because in case you would want to generate only plist you will do the same operation - selecting the rectangle.
Use preview to crop out all the images separately. Then use zwoptex or texture packer to combine them all and generate the spritesheet with .png and .plist
Other than that it is difficult to figure out what is the rect of each image. If you are a good programmer you can write a tool to analyze the png and extract out the information which can be used to identify the rectangles, but my advice is to do it manually.
Divide your image using an image editor. Then add it to a spritesheet generator (like Sprite Master). Then you are free to make your output as you want by just changing the parameters.
Sprite Master will have a feature like parsing prepared spritesheet to individual images in following versions.
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