This how I add an image:
UIImageView *imageHolder = [[UIImageView alloc] initWithFrame:
CGRectMake((self.view.frame.size.width/2) - (290/2),(self.view.frame.size.height) - (140 * 1.8), 290, 140)];
UIImage *image = [UIImage imageNamed:#"no-pins.png"];
imageHolder.image = image;
imageHolder.contentMode = UIViewContentModeScaleAspectFit;
// optional:
// [imageHolder sizeToFit];
[self.view addSubview:imageHolder];
The size of the image (retina version) is exactly the same size as in CGRectMake above. However the image is a little blurred. I only can reduce the blur when I edit the image and give it a higher resolution in photoshop.
But images that I add through storyboard are all fine in quality. Any ideas what might be wrong?
For retina graphics, the image size should be twice the size of the frame of the image view. This allows the image to use a scale of 2 to take advantage of the retina screen capability. So, you should have one image of size 290x140 (if you are supporting non-retina devices) and one image of size 580x280 (this is the #2x image).
The frame of the view is the description of the position and size of the view within the view hierarchy (in terms of the superview coordinate system). If you have fractional values in the frame size or position you can get 'blurring' effects.
Related
I added a uiview as a subview on a view controller programmatically (called contentView). I also added an image on that uiview programmatically. Every time I run the app on the iPad the image is stretched! How do I fix the image so that it fits the iPad screen but doesn't stretch the image? I know the drawInRect is what is stretching the image. So how do I fix that?
Here is my code:
UIGraphicsBeginImageContextWithOptions(self.contentView.bounds.size, self.contentView.opaque, 0.0);
[[UIImage imageNamed:#"menu image 2.JPG"] drawInRect:self.contentView.bounds];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
[self.contentView addSubview:imageView];
UIImageView has a property called contentMode which determines how the image layout is handled in the view context. contentMode is of type UIViewContentMode.
The default value is UIViewContentModeScaleToFill which stretches the image without respecting the aspect ratio. I am assuming it is the changing aspect ratio that is causing the issue.
If you wish to scale the image, but keep the aspect ratio, you have two options:
UIViewContentModeScaleAspectFit: This will show the image scaled to fill the view, but not clip any contents (if the aspect ratio doesn't match view size, it will show either horizontal or vertical bands)
UIViewContentModeScaleAspectFill: This will scale the image to fill the view entirely, without any bands - this will result in content being clipped if the image ratio doesn't match the view ratio.
To set the contentMode on the image view in Objective-C, use the following syntax:
UIImage *image = [UIImage imageNamed:#"menu image 2.JPG"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
imageView.contentMode = UIViewContentModeScaleAspectFill;
...
You should not need to use the custom context drawing for this to work anymore (thanks to Losiowaty for asking me about this).
Change code as below
UIImage *image = [UIImage imageNamed:#"menu image 2.JPG"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
imageView.contentMode = UIViewContentModeScaleAspectFit;
[self.contentView addSubview:imageView];
I guess your self.contentView.bounds is not having the same aspect ratio as your menu image 2.JPG . For an experiment, please try looking at the menu image 2.JPG's resolution. For example if it is 300x150, it's aspect ratio is (300/150 = 2:1). Set your self.contentView.bounds to this aspect ratio and draw the image and check the results. It will not stretch.
Please add this Single Line of code in your project
yourImage .contentMode = UIViewContentModeScaleAspectFit;
I am using an imageView and it contains different images, but some images are stretched. How do I display the images without any stretch? I have set the contentMode to aspect fit. However, the images are not in the size of the imageView, and it is in different sizes. I want to show the images as the same size without stretching.
imageview1 = [[UIImageView alloc]initWithFrame:CGRectMake(30, 10, 190, 190)];
imageview1.contentMode = UIViewContentModeScaleAspectFit;
imageview1.clipsToBounds = YES;
Please try setting content mode before setting frame like below
imageview1.contentMode = UIViewContentModeScaleAspectFit;
imageview1 = [[UIImageView alloc]initWithFrame:CGRectMake(30, 10, 190, 190)];
imageview1.clipsToBounds = YES;
If you want to display each image without stretching and of same size, than set contentMode property of UIImageView's instance to UIViewContentModeScaleAspectFill. For instance-
imageview1 = [[UIImageView alloc]initWithFrame:CGRectMake(30, 10, 190, 190)];
imageview1.contentMode = UIViewContentModeScaleAspectFill;
imageview1.clipsToBounds = YES;
UIViewContentModeScaleAspectFill, will fill the entire area of image view, keeping the aspect ratio intact. In the process of filling entire image view, either vertical or horizontal length will be fully covered and the filling will continue till the time other dimension is fully filled. In the process, your content(either across vertical or horizontal) will be visible outside the frame. To clip this extra content we have set clipsToBounds property of image view to YES.
UIViewContentModeScaleAspectFit, will fill the image view's area till the time any one length either vertical or horizontal is fully filled keeping the aspect ratio intact. Its useful, if you are not required to show each image as same size as the other direction (if vertical is fully filled than horizontal or vice versa), is not fully covered. Since this will show blank spaces in the direction which is not fully covered.
In my application, i need the user to take a snap of only a 10 letter word (using overlay, which should be right in the centre of the screen of the UIImagePicker), and then in need to show him that image (only the part of the image covered by that rectangle). So, I need to crop that image according to the overlay.
Here, i have taken a picture using UIImagePickerControl. Now, i want to see the dimensions of the image that i have taken..
UIImage *imageToprocess = [info objectForKey:UIImagePickerControllerOriginalImage];
NSLog(#"image width %f", imageToprocess.size.width);
NSLog(#"image height %f", imageToprocess.size.height);
I see the following result on console.. But how is this possible. the dimensions of the image is exceeding the dimension of the iPhone screen size.. (which is 320, 568)
UsingTesseractOCR[524:60b] image width 2448.000000
2013-12-17 16:02:18.962 UsingTesseractOCR[524:60b] image height 3264.000000
Can anybody help me out here?? I have gone through several questions here, but did not understand how to do it.
Please help..
Refer this sample code for image capturing and cropping.
https://github.com/kishikawakatsumi/CropImageSample
For creating overlay, first create a custom view (of full dimensions of camera preview) and add an transparent image with just a rectangle in its background. use this view as overlay view.
myview =[[UIImageView alloc]init];
myview.frame=CGRectMake(0, 0, 320, 431);
// why 431? bcoz height = height of device - height of tabbar present in the
bottom for camera controls of picker
//for iphone 4 ,480-49
myview.backgroundColor =[UIColor clearColor];
myview.opaque = NO;
myview.image =[UIImage imageNamed:#"A45Box.png"];
myview.userInteractionEnabled =YES;
note that you create a background image appropriately (means dimensions). You can also draw rectangle programmatically but this is much easy way.
Secondly, talking about your cropping issue, you have to get your hands dirty....Try these links for help
https://github.com/iosdeveloper/ImageCropper
https://github.com/barrettj/BJImageCropper
https://github.com/ardalahmet/SSPhotoCropperViewController
I have an UIView that contains a UIImageView. The UIImageViews works like the branding logo of the app. When I rotate the device, the containing UIView resizes itself to correspond to the landscape or portrait proportions of the screen.
What I'm trying to achieve is to have the UIImageView scaled accordingly, keeping proportions also on the left margin.
This is the actual code for the top white "banner":
UIView *topBanner = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, height_topBanner)];
[topBanner setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleBottomMargin)];
[topBanner setBackgroundColor:[UIColor whiteColor]];
topBanner.autoresizesSubviews = YES;
// the logo
UIImage *topBanner_logo = [UIImage imageNamed:#"logo.png"];
float logoAspectRatio = topBanner_logo.size.width/topBanner_logo.size.height;
topBanner_logoView = [[UIImageView alloc] initWithFrame:CGRectMake(topBanner.frame.size.width/100*3, topBanner.frame.size.height/100*7, (topBanner.frame.size.height/100*86)*logoAspectRatio, topBanner.frame.size.height/100*86)];
[topBanner_logoView setImage:topBanner_logo];
topBanner_logoView.backgroundColor = [UIColor blueColor];
topBanner_logoView.contentMode = UIViewContentModeScaleAspectFit;
[topBanner_logoView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleBottomMargin|UIViewAutoresizingFlexibleRightMargin)];
[topBanner addSubview:topBanner_logoView];
[self.view addSubview:topBanner];
This is my starting point: portrait iPad on startup:
This is what happens when I rotate it in landscape:
As you can see, the proportions of the UIImage are ok, but I'm getting extra borders (I set the background color of the UIImageView to highlight it) because the UIImageView stretches itself to follow the change of the size of its container, and the UIImage is fit into the UIImageView and put on its center.
The same - reversed - happens when I start the app directly in landscape mode:
Then I rotate it:
... and I get the logo with extra borders on top and bottom.
I do see that I can write a function to recalculate every size on each rotation change, but I'm asking to myself if is there a way to set the UIImageView and the UIImage to make it works without hacking the autorotate/resize procedures of iOS. It sounds so simple!
You can solve this by not using UIViewContentModeScaleAspectFit, and instead calculating the aspect ratio of the image and using that to explicitly the width or height based on the other (width or height).
e.g. I rotate to landscape, and so I want the height to be 80% of the view.
CGFloat w = logo.image.size.width;
CGFloat h = logo.image.size.height;
CGFloat a = w / h;
CGFloat h_use = self.view.height *0.8;
CGFloat w_use = h_use*a;
Furthermore, set the content mode to UIViewContentModeScaleAspectFill instead now that you've explicitly set the aspect ratio.
You have set the auto resizing mask to flexible height and width:
[topBanner_logoView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleBottomMargin|UIViewAutoresizingFlexibleRightMargin)];
If you do not do that, the default is that the view will not chance size, and therefore, the image will not either.
I think it is because of topBanner_logoView.contentMode = UIViewContentModeScaleAspectFit;
Try topBanner_logoView.contentMode = UIViewContentModeCenter or topBanner_logoView.contentMode = UIViewContentModeLeft to prevent the UIImageView's image from resizing (and getting padding).
If the UIImageView is resizing, remove the autoresizing mask.
Say there is cool.png file with dimension 200 X 100 pixels and I'd like to use it for both retina and normal devices.
I need to get size of UIImageView 100 X 50 points.
I tried to decrease the size of UIImageView according to image dimensions and visually I don't see any difference whether I prepare two file with and without scale modifier #2x or use UIImageView to scale it by contentMode property.
BOOL retina = [[UIScreen mainScreen] scale] == 2.0 ? YES : NO;
UIImage *img = [UIImage imageNamed:#"cool.png"];
UIImageView *imgView = [[UIImageView alloc] initWithImage:img];
imgView.contentMode = UIViewContentModeScaleToFill;
CGFloat width = img.size.width;
CGFloat height = img.size.height;
if (!retina) {
width = width/2.0;
height = height/2.0;
}
imgView.frame = CGRectMake (somePoint.x, somePoint.y, width, height);
Is there something wrong in the approach?
You are taking the wrong approach here..
CGRect,Point and Size aren't measured in pixels.. They are points.. Points are iOSes coordinate system and will be scaled to the device... So for example if you make a UIView 320 points wide then it will fill the width on both a retina iPhone or iPad...
so if you want your cool.png to display at 100x50 points on all devices then you can simply set the frame to be 100x50, set the image to cool.png then set the imgView.contentView to UIViewContentModeScaleAspectFit... This will then rescale the 200x100 image to fit of its a non retina device... Then if it was a retina device it would be at full resolution (200x100) but in the 100x50 points...
However the #2x system was made for a reason as having to scale the images down increases loading times as it has to be scaled but if you can't use #2x images then you can still do the above