土浦港 #3

土浦港、土浦市





[Sigma 17-70mmF2.8-4.5DCMacro]
[HDR]

SetGradientAlpha32

PixelFormat.Format32bppArgb の画像に８方向からアルファ値の傾斜をかける
SetGradientAlpha32 をつくった。

ここでやった　AlphaGradient と同じように、LinerGradientBrush をつかって
マスクをつくり、すでに設定されているアルファ値に対して任意の傾斜を
設定できる。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using ImageUtils;

namespace LuminanceToAlpha
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public static bool LuminanceToAlpha(Bitmap bmp, bool bStretch,
            Color baseColor, out Bitmap result32)
        {
            result32 = null;

            if (bmp.PixelFormat != PixelFormat.Format24bppRgb)
                return false;

            int w = bmp.Width;
            int h = bmp.Height;

            Bitmap bw = bmp.Clone() as Bitmap;
            ImgUtils.GrayScale(ref bw);
            if (bStretch) ImgUtils.HistoStretch(ref bw);

            result32 = new Bitmap(w, h, PixelFormat.Format32bppArgb);

            Graphics g = Graphics.FromImage(result32);
            g.Clear(baseColor);
            g.Dispose();

            BmpProc8 src = new BmpProc8(bw);
            BmpProc32 dst = new BmpProc32(result32);

            for (int y = 0; y <h; y++)<br>
                for (int x = 0; x <w; x++)<br>
                {
                    dst[x, y, eRGB.a] = (byte)(255 - src[x, y]);
                }
            ImgUtils.CallDispose(dst, src, bw);

            return true;
        }

        public static bool SetAlpha32(ref Bitmap bmp, int percent)
        {
            if (bmp.PixelFormat != PixelFormat.Format32bppArgb)
                return false;

            int w = bmp.Width;
            int h = bmp.Height;

            double p = percent / 100d;

            BmpProc32 dst = new BmpProc32(bmp);

            for (int y = 0; y <h; y++)<br>
                for (int x = 0; x <w; x++)<br>
                {
                    if (dst[x, y, eRGB.a] == 0) continue;
                    dst[x, y, eRGB.a] = ImgUtils.AdjustByte(dst[x, y, eRGB.a] * p);
                }
            dst.Dispose();

            return true;
        }

        public static void DrawImageCenterAt(Graphics g, Bitmap bmp, int x, int y)
        {
            int xx = x - bmp.Width / 2;
            int yy = y - bmp.Height / 2;

            g.DrawImage(bmp, xx, yy, bmp.Width, bmp.Height);

        }

        public static Bitmap GetGradientMask(int width, int height, float[] factor,
                                                        float[] position, GradientSide gs)
        {
            Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);

            Color endColor = Color.White;
            Color startColor = Color.Black;

            Point start = new Point(-1, 0);
            Point end = new Point(0, 0);

            switch (gs)
            {
                case GradientSide.Left:
                    end.X = width;
                    break;

                case GradientSide.Right:
                    start.X = width;
                    break;

                case GradientSide.Upper:
                    end.Y = height;
                    break;

                case GradientSide.Lower:
                    start.Y = height;
                    break;

                case GradientSide.UpperLeft:
                    end.X = width;
                    end.Y = height;
                    break;

                case GradientSide.UpperRight:
                    start.X = width;
                    end.Y = height;
                    break;

                case GradientSide.LowerLeft:
                    start.Y = height;
                    end.X = width;
                    break;

                case GradientSide.LowerRight:
                    start.X = width;
                    start.Y = height;
                    break;
            }

            Blend bl = new Blend();
            bl.Factors = factor;
            bl.Positions = position;

            LinearGradientBrush br = new LinearGradientBrush(
                                        start, end, startColor, endColor);
            br.Blend = bl;
            //br.GammaCorrection = true;

            Rectangle rct = new Rectangle(0, 0, width, height);

            Graphics g = Graphics.FromImage(bmp);
            g.FillRectangle(br, rct);
            g.Dispose();

            return bmp;
        }

        public static bool SetGradientAlpha32(ref Bitmap bmp32, float[] factor,
                                                 float[] position, GradientSide gs)
        {

            if (bmp32.PixelFormat != PixelFormat.Format32bppArgb)
                return false;

            int w = bmp32.Width;
            int h = bmp32.Height;

            Bitmap mask = GetGradientMask(w, h, factor, position, gs);

            byte a;

            BmpProc24 src = new BmpProc24(mask);
            BmpProc32 dst = new BmpProc32(bmp32);

            for (int y = 0; y <h; y++)<br>
                for (int x = 0; x <w; x++)<br>
                {
                    a = dst[x, y, eRGB.a];
                    if (a == 0) continue;
                    dst[x, y, eRGB.a] = ImgUtils.AdjustByte(a * src[x, y, eRGB.r] / 255);
                }

            ImgUtils.CallDispose(dst, src, mask);            

            return true;

        }

        private void button1_Click(object sender, EventArgs e)
        {
            Bitmap bmp = new Bitmap(@"c:HomeImgWorkSGASample2.png");

            int w = bmp.Width;
            int h = bmp.Height;

            Bitmap tmp1, tmp2;

            LuminanceToAlpha(bmp, true, Color.FromArgb(120, 0, 0), out tmp1);

            tmp2 = tmp1.Clone() as Bitmap;

            float[] position = { 0.0f, 0.2f, 0.4f, 0.6f, 0.8f, 1.0f };
            float[] factor = { 1.0f, 0.9f, 0.6f, 0.15f, 0.03f, 0.0f };

            SetGradientAlpha32(ref tmp2, factor, position, GradientSide.Left);

            Graphics g = this.CreateGraphics();

            for (int i = 0; i <4; i++)<br>
            {
                g.DrawImage(tmp2, 20 + 90 * i, 50 + 45 * i, w, h);
            }

            g.DrawImage(tmp1, 20 + 90 * 4, 50 + 45 * 4, w, h);

            g.Dispose();

            tmp2.Dispose();
            tmp1.Dispose();
            bmp.Dispose();
        }

    }
}

SGASample2

N