public static UIImage ResizeImageWithAspectRatio(this UIImage imageSource, float scale)
{
if (scale > 1.0f)
{
return(imageSource);
}
using (CIContext c = CIContext.Create())
{
var sourceImage = CIImage.FromCGImage(imageSource.CGImage);
var f = new CILanczosScaleTransform
{
Scale = scale,
Image = sourceImage,
AspectRatio = 1.0f
};
var output = f.OutputImage;
var cgi = c.CreateCGImage(output, output.Extent);
return(UIImage.FromImage(cgi, 1.0f, imageSource.Orientation));
}
}
public void CreateRefCount()
{
// Bug #7117
CIImage img = new CIImage(CIColor.FromRgb(0.5f, 0.5f, 0.5f));
Selector retainCount = new Selector("retainCount");
#if MONOMAC
using (var ctx = new CIContext(null)) {
#else
using (var ctx = CIContext.Create()) {
#endif
using (var v = ctx.CreateCGImage(img, new RectangleF(0, 0, 5, 5))) {
int rc = Messaging.int_objc_msgSend(v.Handle, retainCount.Handle);
Assert.AreEqual(1, rc, "CreateCGImage #a1");
}
using (var v = ctx.CreateCGImage(img, new RectangleF(0, 0, 32, 32), CIImage.FormatARGB8, null)) {
int rc = Messaging.int_objc_msgSend(v.Handle, retainCount.Handle);
Assert.AreEqual(1, rc, "CreateCGImage #b1");
}
#if !MONOMAC // CreateCGImage returning null on mac
using (var v = ctx.CreateCGImage(img, new RectangleF(0, 0, 5, 5), CIFormat.ARGB8, null)) {
int rc = Messaging.int_objc_msgSend(v.Handle, retainCount.Handle);
Assert.AreEqual(1, rc, "CreateCGImage #c1");
}
#endif
}
}
public static UIImage FilteredImage(UIImage image)
{
var progress = NSProgress.FromTotalUnitCount(-1);
progress.Cancellable = false;
progress.Pausable = false;
UIImage outputImage;
var filter = new CIPhotoEffectTransfer();
var cgImage = image.CGImage;
var ciImage = CIImage.FromCGImage(cgImage);
filter.SetValueForKey(ciImage, new NSString("inputImage"));
var outputCIImage = filter.OutputImage;
var ciContext = CIContext.Create();
var outputCGImage = ciContext.CreateCGImage(outputCIImage, outputCIImage.Extent);
outputImage = UIImage.FromImage(outputCGImage);
outputCGImage.Dispose();
ciContext.Dispose();
outputCIImage.Dispose();
ciImage.Dispose();
cgImage.Dispose();
filter.Dispose();
progress.CompletedUnitCount = 1;
progress.TotalUnitCount = 1;
return(outputImage);
}
private void setupImage(ImageSource source, UIImageView target)
{
IImageSourceHandler handler = null;
if (source is UriImageSource)
{
handler = new ImageLoaderSourceHandler();
}
else if (source is FileImageSource)
{
handler = new FileImageSourceHandler();
}
else if (source is StreamImageSource)
{
handler = new StreamImagesourceHandler();
}
if (handler != null)
{
UIImage image = target.Image;
if (image != null)
{
using (var context = CIContext.Create())
using (var inputImage = CIImage.FromCGImage(image.CGImage))
using (var filter = new CIGaussianBlur()
{
Image = inputImage, Radius = 15
})
using (var resultImage = context.CreateCGImage(filter.OutputImage, inputImage.Extent))
target.Image = new UIImage(resultImage);
}
}
}
void BlurImage(UIImageView imageView, UIImage image, float radius, float transitionDuration)
{
Task.Run(() =>
{
using (var context = CIContext.Create())
using (var inputImage = CIImage.FromCGImage(image.CGImage))
using (var filter = new CIGaussianBlur()
{
Image = inputImage, Radius = radius
})
using (var resultImage = context.CreateCGImage(filter.OutputImage, inputImage.Extent))
{
var blurimage = new UIImage(resultImage);
Device.BeginInvokeOnMainThread(() =>
{
imageView.Hidden = false;
if (transitionDuration > 0.0f)
{
UIView.Transition(imageView, transitionDuration, UIViewAnimationOptions.TransitionCrossDissolve, animation: () =>
{
imageView.Image = blurimage;
}, completion: null);
}
else
{
imageView.Image = blurimage;
}
});
}
});
}
/// <summary>
/// Resize image maintain aspect ratio
/// </summary>
/// <param name="imageSource"></param>
/// <param name="scale"></param>
/// <returns></returns>
public static UIImage ResizeImageWithAspectRatio(this UIImage imageSource, float scale)
{
if (scale > 1.0f)
{
return(imageSource);
}
using (var c = CIContext.Create())
{
var sourceImage = CIImage.FromCGImage(imageSource.CGImage);
var orientation = imageSource.Orientation;
imageSource?.Dispose();
var transform = new CILanczosScaleTransform
{
Scale = scale,
Image = sourceImage,
AspectRatio = 1.0f
};
var output = transform.OutputImage;
using (var cgi = c.CreateCGImage(output, output.Extent))
{
transform?.Dispose();
output?.Dispose();
sourceImage?.Dispose();
return(UIImage.FromImage(cgi, 1.0f, orientation));
}
}
}
public static UIImage MakeUIImageFromCIImage(this CIImage ciImage)
{
CIContext context = CIContext.Create();
CGImage cgImage = context.CreateCGImage(ciImage, ciImage.Extent);//[context createCGImage: ciImage fromRect:[ciImage extent]];
UIImage uiImage = new UIImage(cgImage);
cgImage.Dispose();
return(uiImage);
}
/// <summary>
/// Resize image maintain aspect ratio
/// </summary>
/// <param name="imageSource"></param>
/// <param name="scale"></param>
/// <returns></returns>
public static UIImage ResizeImageWithAspectRatio(this UIImage imageSource, float scale)
{
if (scale > 1.0f)
{
return(imageSource);
}
using (var c = CIContext.Create())
{
var sourceImage = CIImage.FromCGImage(imageSource.CGImage);
var orientation = imageSource.Orientation;
imageSource?.Dispose();
CILanczosScaleTransform transform = null;
/*if(UIDevice.CurrentDevice.CheckSystemVersion(13, 0))
* {
* transform = new CILanczosScaleTransform
* {
* Scale = scale,
* InputImage = sourceImage,
* AspectRatio = 1.0f
* };
* }
* else*/
//{
transform = new CILanczosScaleTransform
{
Scale = scale,
Image = sourceImage,
AspectRatio = 1.0f
};
//}
var output = transform.OutputImage;
using (var cgi = c.CreateCGImage(output, output.Extent))
{
transform?.Dispose();
output?.Dispose();
sourceImage?.Dispose();
return(UIImage.FromImage(cgi, 1.0f, orientation));
}
}
}
/// <summary>
/// Resize image maintain aspect ratio
/// </summary>
/// <param name="imageSource"></param>
/// <param name="scale"></param>
/// <returns></returns>
public static UIImage ResizeImageWithAspectRatio(this UIImage imageSource, float scale)
{
if (scale > 1.0f)
{
return(imageSource);
}
using var c = CIContext.Create();
var sourceImage = CIImage.FromCGImage(imageSource.CGImage);
var orientation = imageSource.Orientation;
imageSource?.Dispose();
CILanczosScaleTransform transform = null;
if (UIDevice.CurrentDevice.CheckSystemVersion(13, 0))
{
transform = new CILanczosScaleTransform
{
Scale = scale,
InputImage = sourceImage,
AspectRatio = 1.0f
};
}
else
{
transform = new CILanczosScaleTransform
{
Scale = scale,
#pragma warning disable CS0618 // Type or member is obsolete
Image = sourceImage,
#pragma warning restore CS0618 // Type or member is obsolete
AspectRatio = 1.0f
};
}
var output = transform.OutputImage;
using var cgi = c.CreateCGImage(output, output.Extent);
transform?.Dispose();
output?.Dispose();
sourceImage?.Dispose();
return(UIImage.FromImage(cgi, 1.0f, orientation));
}
public async void Sample3Png()
{
await _api.Init("eng");
using (var stream = LoadSample("sample3.png"))
using (var image = new CIImage(NSData.FromStream(stream)))
using (var blur = new CIGaussianBlur())
using (var context = CIContext.Create()) {
blur.SetDefaults();
blur.Image = image;
blur.Radius = 0;
using (var outputCiImage = context.CreateCGImage(blur.OutputImage, image.Extent))
using (var newImage = new UIImage(outputCiImage)) {
var result = await((TesseractApi)_api).Recognise(newImage);
Assert.IsTrue(result);
Assert.AreEqual(
"the quick brown fox\njumps over the lazy dog-\n\nTHE QUICK BROlLIN FOX\nJUMPS OVER THE LAZY DOG.\n\n",
_api.Text);
}
}
}