I am simply using this code to transform imageView to scale double or triple.
imageView.transform = CGAffineTransformScale(CGAffineTransformIdentity, scale, scale);
I am drawing lines on this imageView in drawRect,after scaling everything got scaled. What i want is those lines which i am drawing should remain of same size or width after scaling.In order to do that ,i am redrawing lines on scaled imageView with proportional less height and width but result is like lines got blurred/shady.I think on transforming the pixels size also got increase of imageView..I want to know is there any way to draw proper lines without any blurred effect on transformed imageView etc..
Draw the lines AFTER you scale the image. Just change the width of the line to be the same scale (ie image is 4x, line width is 4x).
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I have to resize image i.e if its dimension is 3456x5184 to 700X700 as my code needs image with less number of pixels otherwise it takes too much time to give results.So, when I use imresize command it changes the dimensions of image but at the same time it changes the shape of image i.e the circle in image which I also need to detect looks like oval instead of being cirle. I need your suggestions to resolve this problem. I am really grateful to you people.
Resizing images is done by either subsampling (to get smaller images) or some kind of interpolation (to get larger images)
Input is either a factor or a final dimension for width and height.
The only way to fit a rectangle into a square by simply resizing it is to use different scales for width and height. Which of course will yield in a distorted image.
To achieve what you want you can either crop a 700x700 region from your image or resize image using the same factor for with and height. Then you can fit the larger dimension into 700 and fill the rest around the other dimension with black or whatever you prefer.
I have a UIImageView with a frame of (0, 0, 568, 300) containing a UIImage with a native size of 512x384 pixels. The contentmode is set to Aspect fit.
If the user double-Taps on the view I change the size of the UIImageView with the following code:
self.imageViewerViewController.imageView.frame = CGRectMake(0, -63, 568, 426);
the result is that the right edge of the image is distorted, it does not properly scale to the new size.
Attached is an image with a black and white matrix, the distortion is on the right.
It seems that the right column of pixels is repeated to the right edge of the view.
Can anyone help?
I have changed the creation of the affected UIImageView from a xib file to creating it in code and using the method - (id)initWithFrame:(CGRect)aRect: with the maximum size of the scaled image for aRect. Now the image is properly scaled.
Obviously the UIImageView in the xib file has been inited with a 512x384 pixel frame.
I am making a custom View where I am plotting a curve. Now I want the background of that curve to be like a graph paper.
shall I use a vertical and horizontal lines Or draw a series of rectangles Or use background image?
currently I am using vertical and horizontal lines but the problem is even when I am setting the thickness of the line to be 1 pixel, It still seems to be thicker and If I reduce the thickness to say 0.5 then the color becomes lighter than what I have set it to.
For this kind of thing, if you don't expect to have to make many, many dynamic changes to the background image, you could just use a carefully-crafted .png. You can even make the thing a single square and then use
view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"template"]];
Although, if you're doing plot work, then you may want to draw the lines manually as you are. The answer to your question then is to make the stroke width 1.0 but to draw the lines at the halves: so to draw a vertical line down the 100th x pixel column, move the cursor to (99.5, 0.0) and stroke to (99.5, 480.0). CoreGraphics drawing routines draw your stroke centered on the theoretical line you create, and will antialias to physical pixels as necessary.
I came across issue where I need to animate height change of UILabel frame or its enclosing view's frame. Label is multiline.
The issue is that given with large text which does not fit initially into label(say it takes 3 lines), then animating the label's height to increase, immediately changing 3 line to 4 and then animating the frame increase.
Opposite effect is when the text fully fit into label(4 lines), then I animate height decrease, 4 lines are instantly becoming 3 and only then I see animating frame size decrease.
This is of course not good for an eye.
What I expect is something like keep the label's origin.y intact and then as frame is increasing the more text is revealing from the bottom. The ellipsis may convert to missing word instantly, that is not a problem.
If you want to keep origin.y intact then you have to animate it with CoreAnimation stuff.
Set once:
label.layer.anchorPoint = CGPointMake(0,0); //I believe 0,0 is the upper left or it was 0,1?
after doing this you just need to change the size accordinly:
I would measure the text first (With NSString's methods)and see if the label needs to be resized.
In case it needs to then adjust label.numberOfLines and label.layer.bounds = CGRectMake(label.layer.bounds.origin.x,label.layer.bounds.origin.y,
label.layer.size.width, newHeight);
This should work
I hope this helps.
I use a full screen imageView to display the image, as follows:
UIImageView*imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0,0,320,480)]
imageView.contentMode=UIViewContentModeScaleAspectFit;
imageView.image=srcImage;
As the srcImage size differs, its position (frame) in the imageView differs, how can I
get the position of the image in imageView?
thanks a lot.
You have to do the math yourself. Calculate the aspect ratio of your image and compare with the aspect ratio of the image view's bounds.