The following code behaves very oddly. It adds some extra spacing at the bottom of the image, and I can not see why. Result of code:
And this is the code that I am working with:
public static Image ReDraw(this Image main, int w, int h,
CompositingQuality quality = CompositingQuality.Default, //linear?
SmoothingMode smoothing_mode = SmoothingMode.None,
InterpolationMode ip_mode = InterpolationMode.NearestNeighbor)
{
//size
double dbl = (double)main.Width / (double)main.Height;
//preserve size ratio
if ((int)((double)h * dbl) <= w)
w = (int)((double)h * dbl);
else
h = (int)((double)w / dbl);
//draw
Image newImage = new System.Drawing.Bitmap(w, h);
Graphics thumbGraph = Graphics.FromImage(newImage);
thumbGraph.CompositingQuality = quality;
thumbGraph.SmoothingMode = smoothing_mode;
thumbGraph.InterpolationMode = ip_mode;
thumbGraph.Clear(Color.Transparent);
thumbGraph.DrawImage(main, 0, 0, w, h);
thumbGraph.DrawImage(main,
new System.Drawing.Rectangle(0, 0, w, h),
new System.Drawing.Rectangle(0, 0, main.Width, main.Height),
System.Drawing.GraphicsUnit.Pixel);
return newImage;
}
thumbGraph.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
Related
I want to resize the image coming through file uploader. For that I was referred to the following:
How to set Bitmap.Width and Bitmap.height
(Javed Akram's Answer)
Made following code:
Dim imgSmall As Bitmap = New Bitmap(FUpload.PostedFile.InputStream, False)
imgSmall.Size = New Size(250, 300)
But giving me error:
Size is read-only property.
How can I resize the image in this case?
It is read-only; you'll have to create a new bitmap from it. Try this: -
internal static Image ScaleByPercent(Image image, Size size, float percent)
{
int sourceWidth = image.Width,
sourceHeight = image.Height;
int destWidth = (int)(sourceWidth * percent),
destHeight = (int)(sourceHeight * percent);
if (destWidth <= 0)
{
destWidth = 1;
}
if (destHeight <= 0)
{
destHeight = 1;
}
var resizedImage = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
resizedImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
// get handle to new bitmap
using (var graphics = Graphics.FromImage(resizedImage))
{
InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
// create a rect covering the destination area
var destRect = new Rectangle(0, 0, destWidth, destHeight);
var brush = new SolidBrush(drawing.Color.White);
graphics.FillRectangle(brush, destRect);
// draw the source image to the destination rect
graphics.DrawImage(image,
destRect,
new Rectangle(0, 0, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
}
return resizedImage;
}
This is from a site I have in production; if you want I can send you the code that works out how to keep the correct aspect ratio when resizing (i.e. what gets passed in the 'size' parameter)
Hope that helps
I have a big image in good quality (for my needs), i need resize to small size (30 x 30px), I resize it with graphic.DrawImage. But when i resize it become blurred and little lighter.
also I have try CompositingQuality and InterpolationMode, but it all was bad.
Example, that quality i'm trying get.
My result
Edited
Image of icon i draw myself, maybe it will be better draw it small without resizing?
Edit2
Resizeing code:
Bitmap tbmp;
//drawing all my features in tbmp with graphics
bmp = new Bitmap(width + 5, height + 5);
bmp.MakeTransparent(Color.Black);
using (var gg = Graphics.FromImage(bmp))
{
gg.CompositingQuality = CompositingQuality.HighQuality;
// gg.SmoothingMode = SmoothingMode.HighQuality;
gg.InterpolationMode = InterpolationMode.HighQualityBicubic;
gg.DrawImage(tbmp, new Rectangle(0, 0, width, height), new Rectangle(GXMin, GYMin, GXMax + 20, GYMax + 20), GraphicsUnit.Pixel);
gg.Dispose();
}
I use this method as a way to get a thumbnail image (of any size) from an original (of any size). Note that there are inherent issues when you ask for a size ratio that varies greatly from that of the original. Best to ask for sizes that are in scale to one another:
public static Image GetThumbnailImage(Image OriginalImage, Size ThumbSize)
{
Int32 thWidth = ThumbSize.Width;
Int32 thHeight = ThumbSize.Height;
Image i = OriginalImage;
Int32 w = i.Width;
Int32 h = i.Height;
Int32 th = thWidth;
Int32 tw = thWidth;
if (h > w)
{
Double ratio = (Double)w / (Double)h;
th = thHeight < h ? thHeight : h;
tw = thWidth < w ? (Int32)(ratio * thWidth) : w;
}
else
{
Double ratio = (Double)h / (Double)w;
th = thHeight < h ? (Int32)(ratio * thHeight) : h;
tw = thWidth < w ? thWidth : w;
}
Bitmap target = new Bitmap(tw, th);
Graphics g = Graphics.FromImage(target);
g.SmoothingMode = SmoothingMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
g.InterpolationMode = InterpolationMode.High;
Rectangle rect = new Rectangle(0, 0, tw, th);
g.DrawImage(i, rect, 0, 0, w, h, GraphicsUnit.Pixel);
return (Image)target;
}
I have to display image in photo gallery # width=200 height=180, but while uploading images I have to resize it , but the problem is every image have different resolution. How can I resize the images with different resolution so that images remain intact.
Here is my code :
private void ResizeImage()
{
System.Drawing.Image ImageToUpload = System.Drawing.Image.FromStream(FileUpload1.PostedFile.InputStream);
byte[] image = null;
int h = ImageToUpload.Height;
int w = ImageToUpload.Width;
int r = int.Parse(ImageToUpload.VerticalResolution.ToString());
int NewWidth = 200;//constant
int NewHeight = 180;//constant
byte[] imagesize = FileUpload1.FileBytes;
System.Drawing.Bitmap BitMapImage = new System.Drawing.Bitmap(ImageToUpload, NewWidth, NewHeight);//this line gives horrible output
MemoryStream Memory = new MemoryStream();
BitMapImage.Save(Memory, System.Drawing.Imaging.ImageFormat.Jpeg);
Memory.Position = 0;
image = new byte[Memory.Length + 1];
Memory.Read(image, 0, image.Length);
}
if resolution is 96 and if I set maxwidth=200 then its height would be 150 then only the image looks small and accurate. Can't we resize image in desired way so that it looks exact?
The function will resize the image maintaining aspect ratio.
public static Image Resize(Image originalImage, int w, int h)
{
//Original Image attributes
int originalWidth = originalImage.Width;
int originalHeight = originalImage.Height;
// Figure out the ratio
double ratioX = (double)w / (double)originalWidth;
double ratioY = (double)h / (double)originalHeight;
// use whichever multiplier is smaller
double ratio = ratioX < ratioY ? ratioX : ratioY;
// now we can get the new height and width
int newHeight = Convert.ToInt32(originalHeight * ratio);
int newWidth = Convert.ToInt32(originalWidth * ratio);
Image thumbnail = new Bitmap(newWidth, newHeight);
Graphics graphic = Graphics.FromImage(thumbnail);
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;
graphic.Clear(Color.Transparent);
graphic.DrawImage(originalImage, 0, 0, newWidth, newHeight);
return thumbnail;
}
Usage
Image BitMapImage = Resize(ImageToUpload, NewWidth, NewHeight);
Here i keep height fixed to 180 to maintain aspect ratio. It will resize the image and save to disk. The return value is the percentage value which i use in 'background-size' css.
public float ResizePhoto(string filepath, string filename)
{
var path = Path.Combine(filepath, filename);
var newPath = Path.Combine(filepath, "sml_" + filename);
Image orgImage = Image.FromFile(path);
float fixedHt = 180f;
int destHeight, destWidth;
float reqScale;
if(orgImage.Height > fixedHt)
{
destHeight = (int)fixedHt;
destWidth = (int)(fixedHt / orgImage.Height * orgImage.Width);
reqScale = destWidth / destHeight * 100;
}
else
{
destHeight = orgImage.Height;
destWidth = orgImage.Width;
reqScale = fixedHt / destHeight * 100;
}
Bitmap bmp = new Bitmap(destWidth, destHeight);
bmp.SetResolution(orgImage.HorizontalResolution,orgImage.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmp);
grPhoto.DrawImage(orgImage,
new Rectangle(0, 0, destWidth, destHeight),
new Rectangle(0, 0, orgImage.Width, orgImage.Height),
GraphicsUnit.Pixel);
bmp.Save(newPath);
return reqScale;
}
How would you resize a JPEG image, to a fixed width whilst keeping aspect ratio? In a simple way, whilst preserving quality.
This will scale in the vertical axis only:
public static Image ResizeImageFixedWidth(Image imgToResize, int width)
{
int sourceWidth = imgToResize.Width;
int sourceHeight = imgToResize.Height;
float nPercent = ((float)width / (float)sourceWidth);
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap b = new Bitmap(destWidth, destHeight);
Graphics g = Graphics.FromImage((Image)b);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
g.Dispose();
return (Image)b;
}
If you are reducing the width by 25 percent to a fixed value, you must reduce the height by 25 percent.
If you are increasing the width by 25 percent to a fixed value, you must increasing the height by 25 percent.
It's really straight forward.
Assuming there is a (double width) variable:
Image imgOriginal = Bitmap.FromFile(path);
double height = (imgOriginal.Height * width) / imgOriginal.Width;
Image imgnew = new Bitmap((int)width, (int)height, PixelFormat.Format32bppArgb);
Graphics g = Graphics.FromImage(imgnew);
g.DrawImage(imgOriginal, new Point[]{new Point(0,0), new Point(width, 0), new Point(0, height)}, new Rectangle(0,0,imgOriginal.Width, imgOriginal.Height), GraphicsUnit.Pixel);
In the end you´ll have a new image with widthxheight, then, you´ll need to flush the graphics e save the imgnew.
I think there are plenty of samples of this if you search for them. Here's the one I commonly use...
public static Stream ResizeGdi(Stream stream, System.Drawing.Size size)
{
Image image = Image.FromStream(stream);
int width = image.Width;
int height = image.Height;
int sourceX = 0, sourceY = 0, destX = 0, destY = 0;
float percent = 0, percentWidth = 0, percentHeight = 0;
percentWidth = ((float)size.Width / (float)width);
percentHeight = ((float)size.Height / (float)height);
int destW = 0;
int destH = 0;
if (percentHeight < percentWidth)
{
percent = percentHeight;
}
else
{
percent = percentWidth;
}
destW = (int)(width * percent);
destH = (int)(height * percent);
MemoryStream mStream = new MemoryStream();
if (destW == 0
&& destH == 0)
{
image.Save(mStream, System.Drawing.Imaging.ImageFormat.Jpeg);
return mStream;
}
using (Bitmap bitmap = new Bitmap(destW, destH, System.Drawing.Imaging.PixelFormat.Format48bppRgb))
{
using (System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(bitmap))
{
//graphics.Clear(Color.Red);
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.DrawImage(image,
new Rectangle(destX, destY, destW, destH),
new Rectangle(sourceX, sourceY, width, height),
GraphicsUnit.Pixel);
}
bitmap.Save(mStream, System.Drawing.Imaging.ImageFormat.Jpeg);
}
mStream.Position = 0;
return mStream as Stream;
}
Example of the calling code...
Stream stream = File.Open(filePath, FileMode.Open, FileAccess.Read, FileShare.None);
resizedStream = ImageUtility.ResizeGdi(stream, new System.Drawing.Size(resizeWidth, resizeHeight));
A quick search on code project has found the following article. It allows for resizing of images which accepts a boolean to restrain the new image to keep the originals aspect ratio. I'm unsure of what the quality is like as no screenshots were provided. See the article here
I am trying to print my form using GDI ,but when I print it ,the quality of the print is not that good(donknow whether Image getting aliased?) ,form size is 700x700 ,also there is one parameter which dint understood -raster op code-,here is code am using...
private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
{
Graphics g1 = this.CreateGraphics();
System.Drawing.Image MyImage = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height, g1);
Graphics g2 = Graphics.FromImage(MyImage);
IntPtr dc1 = g1.GetHdc();
IntPtr dc2 = g2.GetHdc();
BitBlt(dc2, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height, dc1, 0, 0, 13369376);
g1.ReleaseHdc(dc1);
g2.ReleaseHdc(dc2);
Bitmap bmp = new Bitmap(MyImage);
int x = e.MarginBounds.X;
int y = e.MarginBounds.Y;
int width = bmp.Width;
int height = bmp.Height;
if ((width / e.MarginBounds.Width) > (height / e.MarginBounds.Height))
{
width = e.MarginBounds.Width;
height = bmp.Height * e.MarginBounds.Width / bmp.Width;
}
else
{
height = e.MarginBounds.Height;
width = bmp.Width * e.MarginBounds.Height / bmp.Height;
}
System.Drawing.Rectangle destRect = new System.Drawing.Rectangle(x, y, width, height);
e.Graphics.DrawImage(bmp, destRect, 0, 0, bmp.Width, bmp.Height, System.Drawing.GraphicsUnit.Pixel);
}
Maybe you have a problem with the original image. Give me a link to an image. Check the image size.
Try insert line
g2.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
Good luck!
It is normal that the result will be scaled and aliased. The source has too few pixels compared to the resolution of a modern printer.
Consider using WPF, that uses a vector based rendering thus there's no loss/distortion when scaling.
Cheers