CreateThumbnails.cs
- //
- // This code is part of Document Solutions for Imaging demos.
- // Copyright (c) MESCIUS inc. All rights reserved.
- //
- using System;
- using System.IO;
- using System.Drawing;
- using System.Collections.Generic;
- using System.Linq;
- using GrapeCity.Documents.Drawing;
- using GrapeCity.Documents.Text;
- using GrapeCity.Documents.Imaging;
- using GCTEXT = GrapeCity.Documents.Text;
- using GCDRAW = GrapeCity.Documents.Drawing;
-
- namespace DsImagingWeb.Demos
- {
- // This sample demonstrates how to resize (downscale) an existing image
- // to create a thumbnail, using different interpolation modes.
- public class DownscaleImage
- {
- public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)
- {
- var origImagePath = Path.Combine("Resources", "Images", "minerva.jpg");
- // Create and fill the target bitmap:
- var targetBmp = new GcBitmap(pixelSize.Width, pixelSize.Height, true, dpi, dpi);
- using (var g = targetBmp.CreateGraphics(Color.FromArgb(unchecked((int)0xff004d99))))
- {
- // creating a graphics with a fill color does what we need
- }
- const int fontSize = 16, fpad = 4, xpad = 10, ypad = 3;
- TextFormat tf = new TextFormat
- {
- ForeColor = Color.FromArgb(unchecked((int)0xffffcc00)),
- Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "times.ttf")),
- FontSize = fontSize,
- };
- using (var origBmp = new GcBitmap())
- {
- using (var stm = new FileStream(origImagePath, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.RandomAccess))
- origBmp.Load(stm);
-
- // Bitwise copy the original image with the original size:
- targetBmp.BitBlt(origBmp, 0, 0);
- using (var g = targetBmp.CreateGraphics(null))
- g.DrawString($"Original image ({origBmp.Width} by {origBmp.Height} pixels)", tf, new PointF(fpad, origBmp.Height + fpad));
- int dx = (int)origBmp.Width + xpad;
-
- // Scale down the image using the various interpolation modes,
- // and render those on the right of the original:
- float f = (origBmp.Height - ypad * 3) / origBmp.Height / 4;
- int twidth = (int)Math.Round(origBmp.Width * f);
- int theight = (int)Math.Round(origBmp.Height * f);
-
- using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.NearestNeighbor))
- targetBmp.BitBlt(bmp, dx, 0);
- drawCaption("InterpolationMode.NearestNeighbor", dx, 0);
-
- using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Linear))
- targetBmp.BitBlt(bmp, dx, theight + ypad);
- drawCaption("InterpolationMode.Linear", dx, theight + ypad);
-
- using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Cubic))
- targetBmp.BitBlt(bmp, dx, (theight + ypad) * 2);
- drawCaption("InterpolationMode.Cubic", dx, (theight + ypad) * 2);
-
- using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Downscale))
- targetBmp.BitBlt(bmp, dx, (theight + ypad) * 3);
- drawCaption("InterpolationMode.Downscale", dx, (theight + ypad) * 3);
- //
- void drawCaption(string caption, float x, float y)
- {
- using (var g = targetBmp.CreateGraphics(null))
- g.DrawString(caption, tf, new PointF(x + twidth + fpad, y + fpad));
- }
- }
- return targetBmp;
- }
- }
- }
-