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));
}
}
/// <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));
}
}
}
/// <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));
}
CIImage LanczosScaleTransform ()
{
var lanczos_scale_transform = new CILanczosScaleTransform () {
Image = heron
};
return lanczos_scale_transform.OutputImage;
}
