How resize image without losing quality - c#

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;
}

Related

Issue with horizontally resizing BMP Image (C#)

Link to Project: https://github.com/FFladenmuller/resize-bmp
Code works for a resize with a factor of 1. However, if trying a larger factor and I open the image, Photos says: "It looks like we don't support this file format".
I have not added in padding yet but I have only worked with images whose width is divisible by 4.
For loop to add BGR bytes to new Image:
for (int i = 54; i < oldBMP.Info.Count - 2; i += 3)
{
for(int j = 0; j < sizeMultiplier; j++)
{
newBMP.Info.Add(oldBMP.Info[i]);
newBMP.Info.Add(oldBMP.Info[i + 1]);
newBMP.Info.Add(oldBMP.Info[i + 2]);
}
}
First for loop to increment through BGR triples, second for loop to add each pixel sizeMultiplier amount of times.
Define the following method:
public static Bitmap ResizeImage(Bitmap image, Size size)
{
try
{
Bitmap result = new Bitmap(size.Width, size.Height);
using (Graphics g = Graphics.FromImage((Image)result))
{
g.CompositingQuality = CompositingQuality.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.DrawImage(image, 0, 0, size.Width, size.Height);
}
return result;
}
catch
{
return image;
}
}
Then, within your code, whenever a resize is needed:
Bitmap image = new Bitmap(#"C:\Path\MyImage.bmp");
Single scaleWidth = 1.2f;
Int32 targetWidth = (Int32)((Single)image.Width * scaleWidth);
Single scaleHeight = 1.0f;
Int32 targetHeight = (Int32)((Single)image.Height * scaleHeight);
Size size = new Size(targetWidth, targetHeight);
Bitmap imageResized = ResizeImage(image, size);
An alternative (that has the drawback of reducing the output quality) is the following:
Bitmap image = new Bitmap(#"C:\Path\MyImage.bmp");
Single scaleWidth = 1.2f;
Int32 targetWidth = (Int32)((Single)image.Width * scaleWidth);
Single scaleHeight = 1.0f;
Int32 targetHeight = (Int32)((Single)image.Height * scaleHeight);
Bitmap imageResized = new Bitmap(image, targetWidth, targetHeight);

c# Image resizing adding extra pixels

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;

Re size image not working C# [duplicate]

This question already has answers here:
Resize image proportionally with MaxHeight and MaxWidth constraints
(3 answers)
Closed 9 years ago.
Am re sizing an image with the following code
using (Image thumbnail = new Bitmap(100, 50))
{
using (Bitmap source = new Bitmap(imageFile))
{
using (Graphics g = Graphics.FromImage(thumbnail))
{
g.CompositingQuality = CompositingQuality.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.SmoothingMode = SmoothingMode.HighQuality;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(source, 0, 0, 100, 50);
}
}
using (MemoryStream ms = new MemoryStream())
{
thumbnail.Save(ms, ImageFormat.Png);
thumbnail.Save(dest, ImageFormat.Png);
}
}
but it is not giving an image of any quality. pixelation is making the image wired.
i have also tried the code
image re size in stack
but am getting a black screen as the result instead of jpg am using png is the only difference.
any suggestion for improving the image quality. i have to re size the transparent image to a size 100by50.
Thanks in advance.
Try this, Assuming you can use it
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;
}

Resize JPEG image to fixed width, while keeping aspect ratio as it is

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

how to improve quality of print when I print Win Form in C#

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

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