I successfully managed to shrink all uploaded images to widths of 700px. Good right? Wrong, because the new shrunken files are now much larger than the original files. My test case took 1600px wide image with a file size of 264KB and turned it into a 700
px wide image with a file size of 457KB.
How is it possible to shrink the width of a file by 50% and have the end result be larger?
The code I used is as follows:
FileUpload FileUpload = (FileUpload)FormView1.FindControl("imageFileUpload");
if (FileUpload.HasFile)
{
const string PictureDirectory = "~/uploads/images/";
string Picture = PictureDirectory + FileUpload.FileName;
string fileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(FileUpload.FileName);
int iteration = 1;
while (System.IO.File.Exists(Server.MapPath(Picture)))
{
Picture = string.Concat(PictureDirectory, fileNameWithoutExtension, "-", iteration, System.IO.Path.GetExtension(FileUpload.FileName).ToLower());
iteration += 1;
}
Bitmap originalBMP = new Bitmap(FileUpload.FileContent);
// Calculate the new image dimensions
int origWidth = originalBMP.Width;
int origHeight = originalBMP.Height;
int sngRatio = origWidth / origHeight;
int newWidth = 700;
int newHeight = newWidth / sngRatio;
// 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(Server.MapPath(Picture));
// Once finished with the bitmap objects, we deallocate them.
originalBMP.Dispose();
newBMP.Dispose();
oGraphics.Dispose();
e.Values["image"] = Picture;
}
Now a new problem seems to be that the values are all being rounded down to the nearest integer. I would just change every int to decimal but Microsoft uses int in their examples. Why does Microsoft use int for ratios?
See the Microsoft example where int is used for ratios. Is it possible for integers to support decimal values without being converted to a decimal?
Member
4 Points
204 Posts
Shrunken Images Create Larger Files After Resizing
May 08, 2020 03:23 AM|CopBlaster|LINK
Hi,
I successfully managed to shrink all uploaded images to widths of 700px. Good right? Wrong, because the new shrunken files are now much larger than the original files. My test case took 1600px wide image with a file size of 264KB and turned it into a 700 px wide image with a file size of 457KB.
How is it possible to shrink the width of a file by 50% and have the end result be larger?
The code I used is as follows:
FileUpload FileUpload = (FileUpload)FormView1.FindControl("imageFileUpload"); if (FileUpload.HasFile) { const string PictureDirectory = "~/uploads/images/"; string Picture = PictureDirectory + FileUpload.FileName; string fileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(FileUpload.FileName); int iteration = 1; while (System.IO.File.Exists(Server.MapPath(Picture))) { Picture = string.Concat(PictureDirectory, fileNameWithoutExtension, "-", iteration, System.IO.Path.GetExtension(FileUpload.FileName).ToLower()); iteration += 1; } Bitmap originalBMP = new Bitmap(FileUpload.FileContent); // Calculate the new image dimensions int origWidth = originalBMP.Width; int origHeight = originalBMP.Height; int sngRatio = origWidth / origHeight; int newWidth = 700; int newHeight = newWidth / sngRatio; // 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(Server.MapPath(Picture)); // Once finished with the bitmap objects, we deallocate them. originalBMP.Dispose(); newBMP.Dispose(); oGraphics.Dispose(); e.Values["image"] = Picture; }Member
4 Points
204 Posts
Re: Shrunken Images Create Larger Files After Resizing
May 08, 2020 08:00 AM|CopBlaster|LINK
Now a new problem seems to be that the values are all being rounded down to the nearest integer. I would just change every int to decimal but Microsoft uses int in their examples. Why does Microsoft use int for ratios?
See the Microsoft example where int is used for ratios. Is it possible for integers to support decimal values without being converted to a decimal?
https://docs.microsoft.com/en-us/dotnet/framework/winforms/advanced/how-to-crop-and-scale-images