ImageOptimizer Class (original) (raw)
Summary
Provides methods to optimize one image or a directory of images in one of the supported formats.
Syntax
public class ImageOptimizer public ref class ImageOptimizer Example
This example will optimize a PNG image file and then save it to a separate folder
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageOptimization;
public void TestPngImageOptimizer()
{
// Initialize the RasterCodecs class
RasterCodecs codecs = new RasterCodecs();
// The input and output location
string inputFileName = Path.Combine(LEAD_VARS.ImagesDir, "LittleGFlyingAlpha.png");
string outputFolder = Path.Combine(LEAD_VARS.ImagesDir, "OptimizedImages");
// Initialize a new Optimizer object
ImageOptimizer optimizer = new ImageOptimizer();
// Optimization Options
ImageOptimizerOptions options = ImageOptimizerOptions.Default;
// Set custom optimization options
options.Distance = 20;
options.Percent = 15;
options.PngQualityFactor = 4;
IntPtr bufferPtr;
int bufferSize = 0;
LoadFileIntoPointer(inputFileName, out bufferPtr, out bufferSize);
if (IntPtr.Zero != bufferPtr && bufferSize > 0)
{
RasterNativeBuffer optBuffer = optimizer.OptimizeBuffer(codecs, bufferPtr, bufferSize, options, null);
// Free orgBuffer.PointerBuffer, since it won't be needed anymore.
Marshal.FreeHGlobal(bufferPtr);
// Save this image into the output folder
// Make sure the output folder exists
if (!Directory.Exists(outputFolder))
Directory.CreateDirectory(outputFolder);
// Get the name of the output file from the input file
string outputFileName = Path.Combine(outputFolder, Path.GetFileName(inputFileName));
// Save the optimized buffer to the output file
using (FileStream fs = File.Create(outputFileName))
{
byte[] optArray = new byte[optBuffer.Length];
Marshal.Copy(optBuffer.Data, optArray, 0, optArray.Length);
fs.Write(optArray, 0, optArray.Length);
}
// Free optBuffer.PointerBuffer, since it won't be needed anymore.
Marshal.FreeHGlobal(optBuffer.Data);
// Compare the original image size with the optimized size.
long orgSize = new FileInfo(inputFileName).Length;
long optSize = new FileInfo(outputFileName).Length;
int percentage = (int)((double)optSize * 100.0 / orgSize);
string message = string.Format(
"Original image size: {0} KB{1}Optimized image size: {2} KB{1}Percentage: {3}%",
orgSize / 1024, Environment.NewLine, optSize / 1024,
100 - percentage);
MessageBox.Show(message);
}
//shutdown the RasterCodecs class.
}
// This method opens an image file and loads it into IntPtr.
private void LoadFileIntoPointer(string fileName, out IntPtr ptr, out int size)
{
using (FileStream fs = File.OpenRead(fileName))
{
// Allocate memory to load the file
size = (int)fs.Length;
ptr = Marshal.AllocHGlobal(size);
// Load in 32K chunks
const int bufferSize = 32 * 1024;
byte[] buffer = new byte[bufferSize];
int bytesToRead;
int bytesLeft = (int)fs.Length;
IntPtr tempPtr = ptr; // where we are
do
{
// read a chunk
bytesToRead = Math.Min(bufferSize, bytesLeft);
if (bytesToRead > 0)
{
fs.Read(buffer, 0, bytesToRead);
// copy into our buffer
Marshal.Copy(buffer, 0, tempPtr, bytesToRead);
// move the temp pointer
tempPtr = new IntPtr(tempPtr.ToInt64() + bytesToRead);
bytesLeft -= bytesToRead;
}
}
while (bytesToRead > 0);
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}