In .net application when the image is processed & merged with another image then its colours are affected.
Image image ---------> Uploaded image
Bitmap xy = new Bitmap(image, image.Width, image.Height); -----> Conversion into Bitmap to perform various operations like resize or merge with another image.
So the “image” object has few “PropertyItems” and when we convert image to Bitmap type of object then these “PropertyItems” array is empty, which means these “PropertyItems” were not moved in this conversion.
Now after this image is moved into Bitmap object for merging with another image, then “PropertyItems” array is empty
Due to loss of these propertyitems, color of the image is changed.
For merging, I'm using below code
public string MergeImages(List<BlockPositionDetailsWithSize> blockPositionDetailsWithSize, int layoutWidth, int layoutHeight)
{
var bitmap = new Bitmap(layoutWidth-75, layoutHeight);
float width = 0, height = 0;
using (var g = Graphics.FromImage(bitmap))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.SmoothingMode = SmoothingMode.HighQuality;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
var bitmapImg = blockPositionDetailsWithSize.Where(b => b.BlockId.Contains("fImageBlock")).FirstOrDefault();
// This loop is placing two images in graphic object
foreach (var block in blockPositionDetailsWithSize)
{
width = block.Width;
height = block.Height;
g.DrawImage(block.BlockImage, block.PosX, block.PosY, block.Width, block.Height);
}
}
ImageCodecInfo jpgEncoder = GetEncoder(ImageFormat.Jpeg); // change image format
System.IO.MemoryStream ms = new System.IO.MemoryStream();
bitmap.SetResolution(288, 288);
System.Drawing.Imaging.Encoder imgEncoder = System.Drawing.Imaging.Encoder.Quality;
EncoderParameters imgEncoderParameters = new EncoderParameters(1);
EncoderParameter imgEncoderParameter = new EncoderParameter(imgEncoder, 95L); //A quality level of 0 corresponds to the greatest compression, and a quality level of 100 corresponds to the least compression.
imgEncoderParameters.Param[0] = imgEncoderParameter;
bitmap.Save(ms, jpgEncoder, imgEncoderParameters);
byte[] byteImage = ms.ToArray();
string base64String = string.Empty;
base64String = Convert.ToBase64String(byteImage); ////Get Base64
return base64String;
}
Image's color quality can be maintained by following code
foreach (System.Drawing.Imaging.PropertyItem item in bitmapImg.BlockImage.PropertyItems)
{
try
{
bitmap.SetPropertyItem(item);
}
catch
{
}
}
Now the issue is I cannot apply one image's property item on the final image(produced after merging). Because when I apply one image's property items onto another image then the second image's color quality is affected but if I don't apply then the first Image's color quality is affected.
So I am looking for the way to merge two images without loosing of any it's property items.
I need to export a Canvas to multiple PNG files. Trying to export the whole canvas to an image and then crop the image failed due to the size of the resulting image (something like 20.000px x 5.000px).
Now the strategy is to split the main canvas into smaller parts and then export each individual part to an image. The resulting image though, doesn't show the image from the main canvas below it.
Any ideas? Here is the code used to test the splitting of the Canvas (the real one is much larger than 1024x1024):
public void TestPrintPartOfCanvas()
{
//the main canvas
var main = new Canvas();
main.Width = 1024;
main.Height = 1024;
main.Background = Brushes.Blue;
//place something inside the canvas
var redRect = new System.Windows.Shapes.Rectangle();
redRect.Fill = Brushes.OrangeRed;
redRect.Width = 128;
redRect.Height = 128;
main.Children.Add(redRect);
// reset current transform (in case it is scaled or rotated)
var transform = main.LayoutTransform;
main.LayoutTransform = null;
// Get the size of canvas
var size = new Size(main.Width, main.Height);
//representing the first part of the main canvas
var part = new Canvas();
part.Width = 256;
part.Height = 256;
part.Background = Brushes.Transparent;
main.Children.Add(part);
// Measure and arrange the surface
main.Measure(size);
main.Arrange(new Rect(size));
// Create a render bitmap and push the part to it
var renderBitmap = new RenderTargetBitmap((int)part.Width, (int)part.Height, 96d, 96d, PixelFormats.Pbgra32);
renderBitmap.Render(part);
// Create a file stream for saving image
using (var outStream = new FileStream("p:/part.png", FileMode.Create))
{
// Use png encoder for our data
var encoder = new PngBitmapEncoder();
// push the rendered bitmap to it
encoder.Frames.Add(BitmapFrame.Create(renderBitmap));
// save the data to the stream
encoder.Save(outStream);
}
// Restore previously saved layout
main.LayoutTransform = transform;
}
You may easily crop a part of the Canvas by adjusting the Arrange rectangle:
var size = new Size(main.Width, main.Height);
main.Measure(size);
var cropOffset = new Point(-256, -256);
main.Arrange(new Rect(cropOffset, size));
var renderBitmap = new RenderTargetBitmap(256, 256, 96d, 96d, PixelFormats.Pbgra32);
renderBitmap.Render(main);
The above crops a 256x256 rectangle at position 256,256.
I have a FrameworkElement and I want to save it as a Height-Resolution Image (Jpeg). I tried the following code, but the results are not what I had hoped. I got an image with bad resolution when I print it with A4 as the paper size.
// ...
FrameworkElement element = this.Content;
element.Measure(new System.Windows.Size(double.PositiveInfinity, double.PositiveInfinity));
element.Arrange(new Rect(element.DesiredSize));
element.UpdateLayout();
// i used element.ActulaHeight and ActualWidth but not works.
RenderTargetBitmap bitmap = new RenderTargetBitmap((int)element.Width, (int)element.Height, GPFReporstPageSizeExtension.DPI, GPFReporstPageSizeExtension.DPI, System.Windows.Media.PixelFormats.Pbgra32);
bitmap.Render(element);
// ....
Finally i solved my problem, i posted the full solution in my blog "gamadev web site":
Saving FrameworkElement as Image
FrameworkElement element = myControl.Content;
// you can set the size as you need.
Size theTargetSize = new Size(1500,2000)
element.Measure(new System.Windows.Size(double.PositiveInfinity, double.PositiveInfinity));
element.Arrange(new Rect(theTargetSize ));
// to affect the changes in the UI, you must call this method at the end to apply the new changes
element.UpdateLayout();
double dpiScale = 300.0 / 96;
double dpiX = 300.0;
double dpiY = 300.0;
RenderTargetBitmap bmp = new RenderTargetBitmap(Convert.ToInt32(
(theTargetSize .Width) * dpiScale),
Convert.ToInt32((theTargetSize .Height) * dpiScale),
dpiX, dpiY, PixelFormats.Pbgra32);
bmp.Render(element);
element.Measure(new System.Windows.Size());
element.Arrange(new Rect());
element.UpdateLayout();
System.Windows.Media.Imaging.BitmapEncoder encoder = new System.Windows.Media.Imaging.PngBitmapEncoder();
MemoryStream myStream = new MemoryStream();
encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(this.CreateRenderTargetBitmap()));
encoder.Save(myStream);
var img = System.Drawing.Bitmap.FromStream(myStream);
Bitmap bmp = new Bitmap((int)theTargetSize .Width, (int)theTargetSize .Height);
var g = Graphics.FromImage(bmp);
g.Clear(System.Drawing.Color.White);
g.DrawImage(this.GetPageAsImage(), (int)this.Margin.Left, (int)this.Margin.Top);
fileName = #”D:\myImage.png”;
bmp.Save(fileName);
I am trying to resize image to width=100 height=100
public ActionResult RegisterUser(userAuthModel user, HttpPostedFileBase userimage)
{
if (userimage.ContentLength > 0 && userimage != null)
{
string fname = userimage.FileName;
var path = Server.MapPath("~/Images/User_DP/" + userimage.FileName);
var image_100 = new System.Drawing.Bitmap(userimage, new Size(100, 100));
userimage.SaveAs(path);
}
.
.
.
.
.
}
Here I am using bitmap approach to resize imgae to some specific width and height.
But this shows me error in line-
var image_100 = new System.Drawing.Bitmap(userimage, new Size(100, 100));
of invalid arguments. How Do Ii resize image with using bitmap?
The System.Drawing.Bitmap class asks for two parameters in the constructor your are using:
System.Drawing.Image
System.Drawing.Size
In your code, you are passing the size correctly, but not the image. HttpPostedFileBase does not extend the Image class.
You will need to change that part of your code. If you are using the HttpPostedFileBase as a stream, then keep in mind that System.Drawing.Bitmap has no constructor asking for a Stream and a Size.
References:
System.Drawing.Image
System.Web.HttpPostedFileBase
you have to use mentioned method it may help you
private static BitmapFrame CreateResizedImage(ImageSource source, int width, int height, int margin)
{
var rect = new Rect(margin, margin, width - margin * 2, height - margin * 2);
var group = new DrawingGroup();
RenderOptions.SetBitmapScalingMode(group, BitmapScalingMode.HighQuality);
group.Children.Add(new ImageDrawing(source, rect));
var drawingVisual = new DrawingVisual();
using (var drawingContext = drawingVisual.RenderOpen())
drawingContext.DrawDrawing(group);
var resizedImage = new RenderTargetBitmap(
width, height, // Resized dimensions
96, 96, // Default DPI values
PixelFormats.Default); // Default pixel format
resizedImage.Render(drawingVisual);
return BitmapFrame.Create(resizedImage);
}
I've got to following function which is called to change the resolution of an image. I want to do this so uploaded image with for example 300dpi will be modified to 72dpi (for web). This question is related to another question here on SO where i'm working on.
I'm creation an extension method for this to be able to use this function on more places in my application, instead of only when uploading new files. (See above mentioned question)
public static byte[] SetDpiTo72(this byte[] imageToFit, string mimeType, Size newSize)
{
using (MemoryStream memoryStream = new MemoryStream(), newMemoryStream = new MemoryStream())
{
memoryStream.Write(imageToFit, 0, imageToFit.Length);
var originalImage = new Bitmap(memoryStream);
using (var canvas = Graphics.FromImage(originalImage))
{
canvas.SmoothingMode = SmoothingMode.AntiAlias;
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
canvas.DrawImage((Image)originalImage,0,0, newSize.Width, newSize.Height);
newBitmap.SetResolution(72, 72);
newBitmap.Save(newMemoryStream, ImageFunctions.GetEncoderInfo(mimeType), null);
}
return newMemoryStream.ToArray();
}
}
The mentioned extension methode is being called in a function similar to the situation below;
if (newSize.Width > originalImage.Width && newSize.Height > originalImage.Height)
{
newSize.Width = originalImage.Width;
newSize.Height = originalImage.Height;
uploadedFileBuffer = uploadedFileBuffer.SetDpiTo72(uploadedFile.ContentType, newSize);
return CreateFile(newSize, uploadedFile, uploadedFileBuffer);
}
The bytearray coming in is the file as an bytearray. It already has the correct size, but I want to change the resolution to 72dpi. However after exectution and saving the image the resolution is still the originale entered resolution, which is 300dpi. How can I do this?
UPDATE AFTER SEVERAL ANSWERS:
public static byte[] SetDpiTo72(this byte[] imageToFit, string mimeType, Size newSize)
{
using (MemoryStream memoryStream = new MemoryStream(), newMemoryStream = new MemoryStream())
{
memoryStream.Write(imageToFit, 0, imageToFit.Length);
var originalImage = new Bitmap(memoryStream);
using (var canvas = Graphics.FromImage(originalImage))
{
canvas.SmoothingMode = SmoothingMode.AntiAlias;
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
canvas.DrawImage((Image)originalImage,0,0, newSize.Width, newSize.Height);
originalImage.SetResolution(72, 72);
var epQuality = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 75);
var epParameters = new EncoderParameters(1);
epParameters.Param[0] = epQuality;
Image newimg = Image.FromStream(memoryStream);
//Getting an GDI+ exception after the execution of this line.
newimg.Save("C:\\test1234.jpg", ImageFunctions.GetEncoderInfo(mimeType), epParameters);
originalImage.Save("test.jpg", ImageFormat.Jpeg);
//This line give me an Argumentexception - Parameter is not valid.
//originalImage.Save(newMemoryStream, ImageFunctions.GetEncoderInfo(mimeType), epParameters);
//newMemoryStream.Close();
}
return newMemoryStream.ToArray();
}
}
The stackstrace which comes with the exception is telling me the following;
at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
at Extensions.ByteArrayExtensions.SetDpiTo72(Byte[] imageToFit, String mimeType, Size newSize) in C:\Website\Project\Extensions\ByteArrayExtensions.cs:line 356
at CMS.Presentation.FileFunctions.CreateFullsizeImage(HttpPostedFileBase uploadedFile, Size newSize, Byte[] uploadedFileBuffer) in C:\Website\Project\CMS.Presentation\FileFunctions.cs:line 197
at CMS.Presentation.FileFunctions.CreateFile(HttpPostedFileBase uploadedFile, INodeService nodeservice, Guid userId, Node parentNode) in C:\Website\Project\CMS.Presentation\FileFunctions.cs:line 53
In the mean time I've also developed another function (see below) resizing just a bitmap. And this seem to work correctly. I can't use this function with my current implementation though because it returns just an Bitmap. Or should i change everything to work with bitmaps?
private static Bitmap ResizeImage(Image image, int width, int height)
{
var frameCount = image.GetFrameCount(new FrameDimension(image.FrameDimensionsList[0]));
var newDimensions = ImageFunctions.GenerateImageDimensions(image.Width, image.Height, width, height);
Bitmap resizedImage;
if (frameCount > 1)
{
//we have a animated GIF
resizedImage = ResizeAnimatedGifImage(image, width, height);
}
else
{
resizedImage = (Bitmap)image.GetThumbnailImage(newDimensions.Width, newDimensions.Height, null, IntPtr.Zero);
}
resizedImage.SetResolution(72,72);
return resizedImage;
}
Ok, I tried it only on files on harddrive, but it should work with streams too.
Bitmap bitmap = new Bitmap(loadFrom);
Bitmap newBitmap = new Bitmap(bitmap);
newBitmap.SetResolution(72, 72);
newBitmap.Save(saveTo);
Took me a while, but I finally found the problem!
The problem lied in the ResizeImage function I used. In the 'GetThumbnailImage' to be specific. I ran into another problem with blurry images, which was explainable because GetThumbnailImage would stretch up the created ThumbNail to the desired size. And the resolution off the thumbnail never changes.
private static Bitmap ResizeImage(Image image, int width, int height)
{
var frameCount = image.GetFrameCount(new FrameDimension(image.FrameDimensionsList[0]));
var newDimensions = ImageFunctions.GenerateImageDimensions(image.Width, image.Height, width, height);
Bitmap resizedImage;
if (frameCount > 1)
{
//we have a animated GIF
resizedImage = ResizeAnimatedGifImage(image, width, height);
}
else
{
resizedImage = (Bitmap)image.GetThumbnailImage(newDimensions.Width, newDimensions.Height, null, IntPtr.Zero);
}
resizedImage.SetResolution(72,72);
return resizedImage;
}
By modifying the function above to the function below I was able to solve the problem using Graphics.DrawImage to redraw the new image before rendering it. Also the GenerateImageDimensions was slightly modified. This taken together the problem was solved.
private static Bitmap ResizeImage(Image image, int width, int height)
{
var frameCount = image.GetFrameCount(new FrameDimension(image.FrameDimensionsList[0]));
var newDimensions = ImageFunctions.GenerateImageDimensions(image.Width, image.Height, width, height);
var resizedImage = new Bitmap(newDimensions.Width, newDimensions.Height);
if (frameCount > 1)
{
//we have a animated GIF
resizedImage = ResizeAnimatedGifImage(image, width, height);
}
else
{
//we have a normal image
using (var gfx = Graphics.FromImage(resizedImage))
{
gfx.SmoothingMode = SmoothingMode.HighQuality;
gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;
gfx.PixelOffsetMode = PixelOffsetMode.HighQuality;
var targRectangle = new Rectangle(0, 0, newDimensions.Width, newDimensions.Height);
var srcRectangle = new Rectangle(0, 0, image.Width, image.Height);
gfx.DrawImage(image, targRectangle, srcRectangle, GraphicsUnit.Pixel);
}
}
return resizedImage;
}
By "changing the resolution", do you actually mean you want to reduce the number of pixels in the image by 72/300? I.e. change a 4000x3000 image to 960x720?
If so, I can't see where your code actually does that. The overload of DrawImage() you're using does this:
Draws the specified image, using its original physical size, at the location specified by a coordinate pair.
Which is exactly what is happening.
Try one of the other overloads such as this one:
Draws the specified Image at the specified location and with the specified size.
for example:
// Create image.
Image newImage = Image.FromFile("SampImag.jpg");
// Create coordinates for upper-left corner of image and for size of image.
int x = 0;
int y = 0;
int width = 450;
int height = 150;
// Draw image to screen.
e.Graphics.DrawImage(newImage, x, y, width, height);
EDIT: per the comments, I understand the OP wants to reduce file size without reducing pixel count. Therefore the files must be recompressed.
I've borrowed some sample code from here:
ImageCodecInfo iciJpegCodec = null;
// This will specify the image quality to the encoder. Change the value of 75 from 0 to 100, where 100 is best quality, but highest file size.
EncoderParameter epQuality = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 75);
// Get all image codecs that are available
ImageCodecInfo[] iciCodecs = ImageCodecInfo.GetImageEncoders();
// Store the quality parameter in the list of encoder parameters
EncoderParameters epParameters = new EncoderParameters(1);
epParameters.Param[0] = epQuality;
// Loop through all the image codecs
for (int i = 0; i < iciCodecs.Length; i++)
{
// Until the one that we are interested in is found, which is image/jpeg
if (iciCodecs[i].MimeType == "image/jpeg")
{
iciJpegCodec = iciCodecs[i];
break;
}
}
// Create a new Image object from the current file
Image newImage = Image.FromFile(strFile);
// Get the file information again, this time we want to find out the extension
FileInfo fiPicture = new FileInfo(strFile);
// Save the new file at the selected path with the specified encoder parameters, and reuse the same file name
newImage.Save(outputPath + "\\" + fiPicture.Name, iciJpegCodec, epParameters);
Rob, I believe that issue with your code is at saving the image - the actual digital image data would be certain number of dots/pixels i.e. (m x n) and setting resolution at bitmap wouldn't/shouldn't change the number dots (and hence physical byte size of image). The resolution information will be stored in the image header (to be used by programs while printing/editing images) - what happens if you store the new bitmap to file instead of mem stream
newBitmap.Save("c:\test.png", ImageFormat.Png);
Check dpi for above file from file -> properties -> summary (advanced). It should be 72 dpi.