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Resize Image But Wrong Border Color (Black 'Auto')

public Image resizeImage(int newWidth, int newHeight, string stPhotoPath)
{
Image imgPhoto = Image.FromFile(stPhotoPath);
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
if (sourceWidth < sourceHeight)
{
int buff = newWidth;
newWidth = newHeight;
newHeight = buff;
}
int sourceX = 0, sourceY = 0, destX = 0, destY = 0;
float nPercent = 0, nPercentW = 0, nPercentH = 0;
nPercentW = ((float)newWidth / (float)sourceWidth);
nPercentH = ((float)newHeight / (float)sourceHeight);
if (nPercentH < nPercentW)
{
nPercent = nPercentH;
destX = System.Convert.ToInt16((newWidth -
(sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = System.Convert.ToInt16((newHeight -
(sourceHeight * nPercent)) / 2);
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(newWidth, newHeight,
PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.Black);
grPhoto.InterpolationMode =
System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
imgPhoto.Dispose();
return bmPhoto;
}
I use such a code to scale down images, but there is a problem that after the images are scaled down, the remaining spaces remain black. Something that should definitely not happen. What is the solution? The background color must be white.

public static class ResizeImage
{
/// <summary>
/// Return new resized size to display the image
/// </summary>
/// <param name="srcrectanle">source rectangle of image or you can pass the
bitmap and set the size accrodingly</param>
/// <param name="initSize">initial size of the page to draw image</param>
/// <returns></returns>
public static SizeF getResizedRectangle(RectangleF srcrectanle, SizeF initSize)
{
float sw = srcrectanle.Width;
float sh = srcrectanle.Height;
float dw = initSize.Width;
float dh = initSize.Height;
float finalHeight, finalWidth;
float Sourceratio = sw / sh;
if (Sourceratio >= 1)
{
finalWidth = (int)dw;
float ratio = sw / dw;
finalHeight = (sh / ratio);
}
else
{
finalHeight = (int)dh;
float ratio = sh / dh;
finalWidth = (sw / ratio);
}
return new SizeF(finalHeight, finalHeight);
}
}
Use this function to resize your image. Hope you have the knowledge of source rectangle and destination rectangle.

Image Getting Stretched when trying to Resize It keeping the aspect Ratio

Im using the following code to resize an image preserving the aspect ratio
public Bitmap resizeImage(System.Drawing.Image imgToResize, SizeF size)
{
int sourceWidth = imgToResize.Width;
int sourceHeight = imgToResize.Height;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)size.Width / (float)sourceWidth);
nPercentH = ((float)size.Height / (float)sourceHeight);
if (nPercentH < nPercentW)
nPercent = nPercentH;
else
nPercent = nPercentW;
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap b = new Bitmap(destWidth, destHeight);
Graphics g = Graphics.FromImage((System.Drawing.Image)b);
// Used to Prevent White Line Border
// g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
g.Dispose();
return b;
}
But images with large width gets compressed and the contents seem packed up into a small space.What im trying to achieve is this : Resize the Large Size/Large Resolution image because processing this will take huge time,So when the image width or height exceeds say 1000 i want to resize the image to a Smaller size eg:1000 Width or Height which ever is larger,so that i can save computation time.But it seems the above code is forcibly trying to fit the image into the 1000X1000 Box when i do
if (y.Width > 1000 || y.Height > 1000)
{
y = new Bitmap( resizeImage(y, new Size(1000, 1000)));
}

Try this, its a bit neater
public static Bitmap ResizeImage(Bitmap source, Size size)
{
var scale = Math.Min(size.Width / (double)source.Width, size.Height / (double)source.Height);
var bmp = new Bitmap((int)(source.Width * scale), (int)(source.Height * scale));
using (var graph = Graphics.FromImage(bmp))
{
graph.InterpolationMode = InterpolationMode.High;
graph.CompositingQuality = CompositingQuality.HighQuality;
graph.SmoothingMode = SmoothingMode.AntiAlias;
graph.DrawImage(source, 0, 0, bmp.Width, bmp.Height);
}
return bmp;
}

Resize Image Keep Aspect Ratio White Line Border

Im using the following code (adapted from Example #2 here ) to Resize an Image keeping the aspect ratio.But i keep getting a white border around the resized images.What im i doing wrong.
Bitmap ResizekeepAspectRatio(Bitmap imgPhoto, int Width, int Height)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
{
nPercent = nPercentH;
destX = System.Convert.ToInt16((Width -
(sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = System.Convert.ToInt16((Height -
(sourceHeight * nPercent)) / 2);
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(Width, Height,
PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.InterpolationMode =
InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
UPDATE:
Sample Resized Image
Zooming in Corner Reveals White Border

Try to change the line
Bitmap bmPhoto = new Bitmap(Width, Height,
PixelFormat.Format24bppRgb);
To
Bitmap bmPhoto = new Bitmap(destWidth, destHeight,
PixelFormat.Format24bppRgb);
Since you want to keep the aspect ratio most of the time you will end up having extra space around the image so if you don't need that extra space then make the new picture size fit to the new destination size
Edit:
Try to comment out the line grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic

Resizing image get damage in pixel

My requirement is to resize an image if it is bigger than 800 X 600 pixels. I have to resize it to 800 X 600 resolution as per aspect ratio.
I am using below code to re-size it:
public string ResizeUserImage(string fullFileName, int maxHeight, int maxWidth, string newFileName)
{
string savepath = System.Web.HttpContext.Current.Server.MapPath("//InitiativeImage//");
try
{
using (Image originalImage = Image.FromFile(fullFileName))
{
int height = originalImage.Height;
int width = originalImage.Width;
int newHeight = maxHeight;
int newWidth = maxWidth;
if (height > maxHeight || width > maxWidth)
{
if (height > maxHeight)
{
newHeight = maxHeight;
float temp = ((float)width / (float)height) * (float)maxHeight;
newWidth = Convert.ToInt32(temp);
height = newHeight;
width = newWidth;
}
if (width > maxWidth)
{
newWidth = maxWidth;
float temp = ((float)height / (float)width) * (float)maxWidth;
newHeight = Convert.ToInt32(temp);
}
Image.GetThumbnailImageAbort abort = new Image.GetThumbnailImageAbort(ThumbnailCallback);
using (Image resizedImage = originalImage.GetThumbnailImage(newWidth, newHeight, abort, System.IntPtr.Zero))
{
//When image is compress then store the image
var guid = Guid.NewGuid().ToString();
string latestFileName = guid + Path.GetExtension(newFileName);
resizedImage.Save(savepath + #"\" + latestFileName);
string finalPath = AppSettings.Domain + "InitiativeImage/" + latestFileName;
return finalPath;
}
}
else if (fullFileName != newFileName)
{
//var guid = Guid.NewGuid().ToString();
//newFileName = guid + Path.GetExtension(newFileName);
//// no resizing necessary, but need to create new file
//originalImage.Save(savepath + #"\" + newFileName);
//string finalPath = AppSettings.Domain + "UserImage/" + newFileName;
return newFileName;
}
return fullFileName;
}
}
catch (Exception)
{
throw;
}
}
It works perfect but resizing image gets damaged in pixel.
See below original image which I am uploading to the server:
After re-sizing it, it is damages like below image:
Hope you got my question. The resized image get damage in pixel. Please let me know where I am wrong or where is the issue.

Pls try out below function.
public void FixedSize(string oldImageFile, int Width, int Height,string finalpath)
{
Bitmap imgPhoto = new Bitmap(oldImageFile);
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
{
nPercent = nPercentH;
destX = System.Convert.ToInt16((Width -
(sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = System.Convert.ToInt16((Height -
(sourceHeight * nPercent)) / 2);
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(destWidth, destHeight,
PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.InterpolationMode =
InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(0, 0, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
bmPhoto.Save(finalpath);
}

From the documentation on Image.GetThumbnailImage method:
The GetThumbnailImage method works well when the requested thumbnail image has a size of about 120 x 120 pixels. If you request a large thumbnail image (for example, 300 x 300) from an Image that has an embedded thumbnail, there could be a noticeable loss of quality in the thumbnail image. It might be better to scale the main image (instead of scaling the embedded thumbnail) by calling the DrawImage method.
But your objective size is around 800x600 pixels, which is way above the indented use.
Thus, I recommend you to take a look at this answer about image resizing.

Resizing images in C#

I have the below method which I found online,which resizes an image to an approximate size, while keeping the aspect ratio.
public Image ResizeImage(Size size)
{
int sourceWidth = _Image.Width;
int sourceHeight = _Image.Height;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)size.Width / (float)sourceWidth);
nPercentH = ((float)size.Height / (float)sourceHeight);
if (nPercentH > nPercentW)
nPercent = nPercentH;
else
nPercent = nPercentW;
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(_Image, 0, 0, destWidth, destHeight);
g.Dispose();
return (Image)b;
}
I usually pass in a size with a width of 100px and a height of 100px - as part of my requirements I can't have any single dimension (height or width) being under 100px, so if the aspect ratio isn't square the other dimension would be higher.
What I'm finding with this method is occasionally one of the dimensions will be under 100px - such as 96px or 99px. How can I change this method to ensure this doesn't happen?

The code is just inappropriate. It doesn't score points for using floating point math, that has a knack for rounding the wrong way so you can easily end up with 99 pixels instead of 100. Always favor integer math so you can control the rounding. And it just doesn't do anything to ensure that one of the dimensions is large enough, the way to end up with 96 pixels. Just write better code. Like:
public static Image ResizeImage(Image img, int minsize) {
var size = img.Size;
if (size.Width >= size.Height) {
// Could be: if (size.Height < minsize) size.Height = minsize;
size.Height = minsize;
size.Width = (size.Height * img.Width + img.Height - 1) / img.Height;
}
else {
size.Width = minsize;
size.Height = (size.Width * img.Height + img.Width - 1) / img.Width;
}
return new Bitmap(img, size);
}
I left a comment to show what you do if you are only want to make sure the image is large enough and accept larger images. It wasn't clear from the question. If that's the case then replicate that if statement in the else clause as well.