quartz-graphics

I'm using the method described at How do I draw a shadow under a UIView? to draw shadow behind a view's content. The shadow is clipped to the view's bounds, although I disabled "Clip Subviews" in Interface Builder for the view. Is it possible to draw a shadow around a view and not only in a view? I don't want to draw the shadow inside the view because the view would receive touch events for the shadow area, which really belongs to the background. It is not encouraged to draw outside view bounds. Maybe you can include the shadow directly in your background... Regards, Instead of manual drawing

Still an iphone dev starter but trying. I would like to have the user touch the screen at which point a pin (dot) will be placed on the view. I have accomplished this (yey) but i would like to have snap to grip effect, and can not come up with a solution. This is how i am placing that dot: CGPoint drawPoint = CGPointMake(lastTouch.x - horizontalOffset, lastTouch.y - >verticalOffset); [drawImage drawAtPoint:drawPoint]; //Tell the image to draw itself I have a grid as a background on a Viewcontroller, overlapping that grid i have a UIView with custom drawing that displays a pin every time the

I'm developing an iPhone app with 3.1.3 SDK. I'm trying to draw a triangle with transparent fill an 1px black stroke with this code: CGContextMoveToPoint(ctx, position.X, position.Y - (size.height / 2)); CGContextAddLineToPoint(ctx, position.X - (size.width / 2), position.Y + (size.height / 2)); CGContextAddLineToPoint(ctx, position.X + (size.width / 2), position.Y + (size.height / 2)); CGContextFillPath(ctx); CGContextSetLineWidth(ctx, 1.0); CGContextStrokePath(ctx); CGContextSetFillColorWithColor(ctx, [[UIColor clearColor] CGColor]); But I get a black filled triangle. What am I doing wrong?

I'm able to crop a view with this code - (UIImage *)captureScreenInRect:(CGRect)captureFrame { CALayer *layer; layer = self.view.layer; UIGraphicsBeginImageContext(self.view.bounds.size); CGContextClipToRect (UIGraphicsGetCurrentContext(),captureFrame); [layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *screenImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return screenImage; } But I have an imageview zoomed in with transform and it isn't shown to scale. How do I capture EXACTLY what the user sees on the screen Aaron Brager The Stack Overflow

I am writing an iOS as and I need to be able to do edge detection in the image. I actually want something similar to Photoshop's trace contour. Since I basically need to get the simplest set of lines to work with.. Thing is I cannot seem to figure out how to do it and frankly I have 0 interest in OpenCV since I spent 5 hours today trying to get any of the 10 or so zips of it I downloaded to compile, in any way shape or form. So I was hoping maybe some one could point me the right way to do it with what's built in to the os.. or maybe an example If haven't used it myself, but are you looking

I am working on an OCR project. My first task is to take an image from iPhone camera and then locate a specific word on the image. Below is a sample image taken by my device, now I want to find the position of word "STATIONERY" and highlight it with a yellow rectangle on image. How can I do that? Do I need to first use an OCR SDK for that (like ABBYY) or can I do this otherwise? If you need to get the coordinates of a specific word, of course you need to perform OCR first. Keep in mind you'll probable have some difficulties with that paticullar image you've attached because of its bottom part.

I want to draw an image using an additive blend mode. But I don't want to use OpenGL. I can't find anything to do this, maybe there's something in Quartz2D? Can anyone point me in the right direction? Cheers, Rich Krzysztof Zabłocki Sure there is enum CGBlendMode which you can use to specify blending operation. use method: CGContextSetBlendMode() or [image drawInRect:CGRectMake(0, 0, width, height) blendMode:mode alpha:1]; more at developer site: link text 来源： https://stackoverflow.com/questions/3908160/draw-an-image-in-additive-blend-mode-without-using-opengl