Develop Reference

c# How to resize any image to specific kilobytes while retaining image type

I've seen a ton of stackoverflow articles for reducing image size, but none of them maintain the original image type (or so I've found). They usually have steps to reduce pixel dimensions, reduce image quality, and convert to a specific type of image (usually jpeg).
I have a group of images that I need to resize. They have various image types, and the filenames are all stored in a database, which makes converting from one image type to another somewhat problematic. I can't just change the filename from png to jpg because then the database won't point at a real file.
Doe anyone have an example of how to resize / reduce images to '256 kilobytes' and maintain the original image type?
For examples, here is the code I'm currently fiddling with.
public static byte[] ResizeImageFile(Image oldImage, int targetSize) // Set targetSize to 1024
{
Size newSize = CalculateDimensions(oldImage.Size, targetSize);
using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format24bppRgb))
{
using (Graphics canvas = Graphics.FromImage(newImage))
{
canvas.SmoothingMode = SmoothingMode.AntiAlias;
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));
MemoryStream m = new MemoryStream();
newImage.Save(m, ImageFormat.Jpeg);
return m.GetBuffer();
}
}
}
Maybe there is a way I can get file fileinfo or mime type first and then switch on the .Save for the type of image?

Here is what I came up with (based on some examples that I found online that weren't 100% complete.
private void EnsureImageRequirements(string filePath)
{
try
{
if (File.Exists(filePath))
{
// If images are larger than 300 kilobytes
FileInfo fInfo = new FileInfo(filePath);
if (fInfo.Length > 300000)
{
Image oldImage = Image.FromFile(filePath);
ImageFormat originalFormat = oldImage.RawFormat;
// manipulate the image / Resize
Image tempImage = RefactorImage(oldImage, 1200); ;
// Dispose before deleting the file
oldImage.Dispose();
// Delete the existing file and copy the image to it
File.Delete(filePath);
// Ensure encoding quality is set to an acceptable level
ImageCodecInfo[] encoders = ImageCodecInfo.GetImageEncoders();
// Set encoder to fifty percent compression
EncoderParameters eps = new EncoderParameters
{
Param = { [0] = new EncoderParameter(Encoder.Quality, 50L) }
};
ImageCodecInfo ici = (from codec in encoders where codec.FormatID == originalFormat.Guid select codec).FirstOrDefault();
// Save the reformatted image and use original file format (jpeg / png / etc) and encoding
tempImage.Save(filePath, ici, eps);
// Clean up RAM
tempImage.Dispose();
}
}
}
catch (Exception ex)
{
this._logger.Error("Could not resize oversized image " + filePath, ex);
}
}
private static Image RefactorImage(Image imgToResize, int maxPixels)
{
int sourceWidth = imgToResize.Width;
int sourceHeight = imgToResize.Height;
int destWidth = sourceWidth;
int destHeight = sourceHeight;
// Resize if needed
if (sourceWidth > maxPixels || sourceHeight > maxPixels)
{
float thePercent = 0;
float thePercentW = 0;
float thePercentH = 0;
thePercentW = maxPixels / (float) sourceWidth;
thePercentH = maxPixels / (float) sourceHeight;
if (thePercentH < thePercentW)
{
thePercent = thePercentH;
}
else
{
thePercent = thePercentW;
}
destWidth = (int)(sourceWidth * thePercent);
destHeight = (int)(sourceHeight * thePercent);
}
Bitmap tmpImage = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(tmpImage);
g.InterpolationMode = InterpolationMode.HighQualityBilinear;
g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
g.Dispose();
return tmpImage;
}

My image is not compressing

Loading code from filesystem:
System.Drawing.Image image = System.Drawing.Image.FromFile(<location of original image>););
Loading code from browser request:
var memoryStream = new MemoryStream();
using (memoryStream)
{
System.Web.HttpContext.Current.Request.Files[upload].InputStream.CopyTo(memoryStream);
memoryStream.ToArray();
}
byte[] bytes = memoryStream.GetBuffer();
// Get the image from the server
System.Drawing.Image image = new System.Drawing.Bitmap( System.Web.HttpContext.Current.Request.Files[upload].InputStream );
Resize image call:
System.Drawing.Image image = this.ResizeImage(
image,
originalImagePath,
ImageSizeType.Original,
null,
null)
Save image call:
image.Save(<location to save>);
The code that doesn't compress the image:
private System.Drawing.Image ResizeImage(System.Drawing.Image image, string filePath, string sizeType, int? _width, int? height )
{
...
System.Drawing.Bitmap b = new System.Drawing.Bitmap(width, resizeHeight);
b.SetResolution(72, 72);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage((System.Drawing.Image)b);
g.CompositingQuality = CompositingQuality.HighSpeed;
//g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.InterpolationMode = InterpolationMode.Low;
g.SmoothingMode = SmoothingMode.HighSpeed;
g.DrawImage(image, 0, 0, width, resizeHeight);
g.Dispose();
return (System.Drawing.Image)b;
}
No matter what I do to this image, when it saves, it saves at a really high kb.
For example... a jpg of 1024 x 768 # 300kb becomes 600 x 400 # 800kb
What am I doing wrong?

As Magnus rightly said, the drawing to the canvas makes no difference to size... of file...
It was the save file part that was being all noob... This is what it should be:
private ImageCodecInfo GetEncoderInfo(string mimeType)
{
// Get image codecs for all image formats
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
// Find the correct image codec
for (int i = 0; i < codecs.Length; i++)
if (codecs[i].MimeType == mimeType)
return codecs[i];
return null;
}
...
if( mimeType.ToLower() == "image/jpeg")
{
ImageCodecInfo jpgEncoder = this.GetEncoderInfo("image/jpeg")
System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality;
EncoderParameters myEncoderParameters = new EncoderParameters(1);
EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 80L);
myEncoderParameters.Param[0] = myEncoderParameter;
image.Save(systemFilePath, jpgEncoder, myEncoderParameters);
}
else
{
image.Save(systemFilePath);
}

How To split a big image into smaller A4 size pieces using DrawImage method of Graphics class

DrawImage method of Graphics class is not creating high quality images. In this method I am splitting a master image into multiple image but the code generating first image in very low quality. But it is generating full black images for remaining height.
public static Bitmap[] Split(byte[] ByteImage)
{
// MasterImage: there is no problem in master image. it is saving it in good quality.
MemoryStream ms = new MemoryStream(ByteImage);
System.Drawing.Image MasterImage = System.Drawing.Image.FromStream(ms);
MasterImage.Save(HttpContext.Current.Server.MapPath("../../../App_Shared/Reports/Temp/MasterImage.Bmp"), ImageFormat.Bmp);
//Split master image into multiple image according to height / 1000
Int32 ImageHeight = 1000, ImageWidth = MasterImage.Width, MasterImageHeight = MasterImage.Height;
int PageCount = 0;
Int32 TotalPages = MasterImage.Height / 1000;
Bitmap[] imgs = new Bitmap[TotalPages];
for (int y = 0; y + 1000 < MasterImageHeight; y += 1000, PageCount++)
{
imgs[PageCount] = new Bitmap(ImageWidth, ImageHeight, PixelFormat.Format32bppPArgb);
using (Graphics gr = Graphics.FromImage(imgs[PageCount]))
{
gr.CompositingQuality = CompositingQuality.HighQuality;
gr.InterpolationMode = InterpolationMode.HighQualityBicubic;
gr.SmoothingMode = SmoothingMode.HighQuality;
//First image now working with this code line
gr.DrawImage(MasterImage, new System.Drawing.Rectangle(0, y, ImageWidth, ImageHeight),new System.Drawing.Rectangle(0, 0, ImageWidth, ImageHeight), GraphicsUnit.Pixel); //new System.Drawing.Rectangle(new Point(0, y), new Size(ImageWidth, ImageHeight)));
//gr.DrawImage(MasterImage, new System.Drawing.Rectangle(0, y, ImageWidth, ImageHeight)); //new System.Drawing.Rectangle(new Point(0, y), new Size(ImageWidth, ImageHeight)));
string FilePath = HttpContext.Current.Server.MapPath("../../../App_Shared/Reports/Temp/Image" + PageCount.ToString() + ".bmp");
imgs[PageCount].Save(FilePath, System.Drawing.Imaging.ImageFormat.Bmp);
//Here it is saving images. I got first image with very poor quality but remaining in total balck color.
gr.Dispose();
}
}
return imgs;
}

As #HansPassant mentioned the source and target rectangle are reversed.
You could also change the structure of your splitting a bit so it could work a bit more flexible, and it might have a better readability at a later time.
class Program
{
static IList<Bitmap> SplitImage(Bitmap sourceBitmap, int splitHeight)
{
Size dimension = sourceBitmap.Size;
Rectangle sourceRectangle = new Rectangle(0, 0, dimension.Width, splitHeight);
Rectangle targetRectangle = new Rectangle(0, 0, dimension.Width, splitHeight);
IList<Bitmap> results = new List<Bitmap>();
while (sourceRectangle.Top < dimension.Height)
{
Bitmap pageBitmap = new Bitmap(targetRectangle.Size.Width, sourceRectangle.Bottom < dimension.Height ?
targetRectangle.Size.Height
:
dimension.Height - sourceRectangle.Top, PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(pageBitmap))
{
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;
g.DrawImage(sourceBitmap, targetRectangle, sourceRectangle, GraphicsUnit.Pixel);
}
sourceRectangle.Y += sourceRectangle.Height;
results.Add(pageBitmap);
}
return results;
}
static void Main(string[] args)
{
string sourceFilename = Environment.CurrentDirectory + #"\testimage.jpg";
Bitmap sourceBitmap = (Bitmap)Image.FromFile(sourceFilename);
var images = SplitImage(sourceBitmap, 79);
int len = images.Count;
for (int x = len; --x >= 0; )
{
var bmp = images[x];
string filename = "Images-" + x + ".bmp";
bmp.Save(Environment.CurrentDirectory + #"\" + filename, ImageFormat.Bmp);
images.RemoveAt(x);
bmp.Dispose();
Console.WriteLine("Saved " + filename);
}
Console.WriteLine("Done with the resizing");
}
}
This would also dynamically size the last image in case the page is less than your specified bitmap height at the end :)

Getting error when try to save file in Asp.net Using c#

This is the error i am getting right now
System.Runtime.InteropServices.ExternalException (0x80004005): A generic error occurred in GDI+. at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
i am using this same code on other website in same machine and there is no problem i really don't know what's going on please give me solution
here is my code
double newHeight = 0;
double newWidth = 0;
double scale = 0;
//create new image object
Bitmap curImage = new Bitmap(filePath);
//Determine image scaling
if (curImage.Height > curImage.Width)
{
scale = Convert.ToSingle(size) / curImage.Height;
}
else
{
scale = Convert.ToSingle(size) / curImage.Width;
}
if (scale < 0 || scale > 1) { scale = 1; }
//New image dimension
newHeight = Math.Floor(Convert.ToSingle(curImage.Height) * scale);
newWidth = Math.Floor(Convert.ToSingle(curImage.Width) * scale);
//Create new object image
Bitmap newImage = new Bitmap(curImage, Convert.ToInt32(newWidth), Convert.ToInt32(newHeight));
Graphics imgDest = Graphics.FromImage(newImage);
imgDest.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
imgDest.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
imgDest.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
imgDest.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
ImageCodecInfo[] info = ImageCodecInfo.GetImageEncoders();
EncoderParameters param = new EncoderParameters(1);
param.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
//Draw the object image
imgDest.DrawImage(curImage, 0, 0, newImage.Width, newImage.Height);
//Save image file
newImage.Save(saveFilePath, info[1], param);
//Dispose the image objects
curImage.Dispose();
newImage.Dispose();
imgDest.Dispose();
}

You will get a GDI error message if the account you're running under cannot save to the path at saveFilePath on this line:
newImage.Save(saveFilePath, info[1], param);

A generic error occurred in GDI+

Hi frnds can anyone help me to solve this problem because i am new for .net world..
The below code is working fine in local server but whenever i try to upload in server it's
getting
"A generic error occurred in GDI+."
if (FileUpload2.PostedFile.ContentType == "image/pjpeg" || FileUpload2.PostedFile.ContentType == "image/jpg" || FileUpload2.PostedFile.ContentType == "image/gif" || FileUpload2.PostedFile.ContentType == "image/jpeg" || FileUpload2.PostedFile.ContentType == "image/png")
{
string filename = FileUpload2.FileName;
// Specify a upload directory
string directory = Server.MapPath(#"datalistimg\");
// Create a bitmap in memory of the content of the fileUpload control
Bitmap originalBMP = new Bitmap(FileUpload2.FileContent);
// Calculate the new image dimensions
int origWidth = originalBMP.Width;
int origHeight = originalBMP.Height;
int sngRatio = origWidth / origHeight;
int newWidth = 218;
int newHeight = (newWidth * origHeight) / origWidth;
// Create a new bitmap which will hold the previous resized bitmap
Bitmap newBMP = new Bitmap(originalBMP, newWidth, newHeight);
// Create a graphic based on the new bitmap
Graphics oGraphics = Graphics.FromImage(newBMP);
// Set the properties for the new graphic file
oGraphics.SmoothingMode = SmoothingMode.AntiAlias;
oGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Draw the new graphic based on the resized bitmap
oGraphics.DrawImage(originalBMP, 0, 0, newWidth, newHeight);
// Save the new graphic file to the server
newBMP.Save(directory + filename);
dfn2 = #"datalistimg/" + filename;
originalBMP = null;
newBMP = null;
oGraphics = null;
fn2 = System.IO.Path.GetFileName(FileUpload2.PostedFile.FileName);
string SaveLocation = Server.MapPath("event") + "\\" + fn2;
fn2 = "event/" + fn2;
FileUpload2.PostedFile.SaveAs(SaveLocation);