Create Uiimage With Solid Color in Swift

Create UIImage with solid color in Swift

Another nice solution,
Swift 3.0

    public extension UIImage {
      convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
        let rect = CGRect(origin: .zero, size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        color.setFill()
        UIRectFill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        guard let cgImage = image?.cgImage else { return nil }
        self.init(cgImage: cgImage)
      }
    }

Swift 2.2 compatible, is to create another constructor in UIImage, in this way:

    public extension UIImage {
        public convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
            let rect = CGRect(origin: .zero, size: size)
            UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
            color.setFill()
            UIRectFill(rect)
            let image = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
        
            guard let cgImage = image?.CGImage else { return nil }
            self.init(CGImage: cgImage)
        }  
    }

In this way you can create the custom colored-image in this way:

    let redImage = UIImage(color: .redColor())

Or, optionally, create the image with a custom size:

    let redImage200x200 = UIImage(color: .redColor(), size: CGSize(width: 200, height: 200))

Create UIImage of a specific size

Here is an answer for you stitch picture in iphone

And base on my experience, I can give you some note:

Propotional scale

- (UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize
{
 UIGraphicsBeginImageContext(CGSizeMake(image.size.width*scaleSize,image.size.height*scaleSize);
 [image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height *scaleSize)];
 UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 return scaledImage;
}

Resize

- (UIImage *)reSizeImage:(UIImage *)image toSize:(CGSize)reSize
{
 UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height));
 [image drawInRect:CGRectMake(0, 0, reSize.width, reSize.height)];
 UIImage *reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 return reSizeImage;
}

Handle specific view

You hava to import QuzrtzCore.framework first

-(UIImage*)captureView:(UIView *)theView
{
 CGRect rect = theView.frame; 
 UIGraphicsBeginImageContext(rect.size); 
 CGContextRef context = UIGraphicsGetCurrentContext(); 
 [theView.layer renderInContext:context]; 
 UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); 
 UIGraphicsEndImageContext(); 
 return img;
}

Handle a range form image

CGRect captureRect = yourRect
CGRect viewRect = self.view.frame;
UIImage *viewImg;
UIImage *captureImg;

UIGraphicsBeginImageContext(viewRect.size); 
CGContextRef context = UIGraphicsGetCurrentContext(); 
[self.view.layer renderInContext:context]; 
viewImg = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext();

captureImg = [UIImage imageWithCGImage:CGImageCreateWithImageInRect(viewImg.CGImage, captureRect)];

Save the image

Save in app

NSString *path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"image.png"];
[UIImagePNGRepresentation(image) writeToFile:path atomically:YES];

Save in album

CGImageRef screen = UIGetScreenImage();
UIImage* image = [UIImage imageWithCGImage:screen];
CGImageRelease(screen);
UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);

How to create a black UIImage?

Depending on your situation, you could probably just use a UIView with its backgroundColor set to [UIColor blackColor]. Also, if the image is solidly-colored, you don't need an image that's actually the dimensions you want to display it at; you can just scale a 1x1 pixel image to fill the necessary space (e.g., by setting the contentMode of a UIImageView to UIViewContentModeScaleToFill).

Having said that, it may be instructive to see how to actually generate such an image:

Objective-C

CGSize imageSize = CGSizeMake(64, 64);
UIColor *fillColor = [UIColor blackColor];
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
[fillColor setFill];
CGContextFillRect(context, CGRectMake(0, 0, imageSize.width, imageSize.height));
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

Swift

let imageSize = CGSize(width: 420, height: 120)
let color: UIColor = .black
UIGraphicsBeginImageContextWithOptions(imageSize, true, 0)
let context = UIGraphicsGetCurrentContext()!
color.setFill()
context.fill(CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height))
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()

Set UIImage color

withTintColor(_:) say: The new image uses the same rendering mode as the original image.

So if original image's rendering mode is .alwaysTemplate, means image will ignoring its color information. you need set mode to .alwaysOriginal:

defaultImage?.withTintColor(.gray, renderingMode: .alwaysOriginal)

How to create a colored 1x1 UIImage on the iPhone dynamically?

You can use CGContextSetFillColorWithColor and CGContextFillRect for this:

Swift

extension UIImage {
    class func image(with color: UIColor) -> UIImage {
        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()

        CGContextSetFillColorWithColor(context, color.CGColor)
        CGContextFillRect(context, rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image
    }
}

Swift3

extension UIImage {
    class func image(with color: UIColor) -> UIImage {
        let rect = CGRect(origin: CGPoint(x: 0, y:0), size: CGSize(width: 1, height: 1))
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()!

        context.setFillColor(color.cgColor)
        context.fill(rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image!
    }
}

Objective-C

+ (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

---

Related Topics