Question

我想创建一个位数组并将它们转换为vb中的位图？我知道如何创建像这样Dim NBitmap as new bitmap(width,height)的位图，然后编辑像NBitmap.setpixel(x,y,color)这样的像素。这很慢，但我认为创建一个数组或其他东西，然后将其转换为位图会更快。但我不知道如何...任何帮助都会很好！例如：

Dim SM = DateTime.Now.Millisecond
Dim Texture As Bitmap = Image.FromFile("C:\Users\Noah\Desktop\graphics\Grass.jpg")
Dim w = 600
Dim h = 600
Dim Pixels(600, 600) As Color
Dim x = 0
Do Until x = 600
    Dim y = 0
    Do Until y = 600
        Pixels(x, y) = Texture.GetPixel(x, y)
        y += 1
    Loop
    x += 1
Loop
Dim EM = DateTime.Now.Millisecond
Dim FM = EM - SM
If FM < 0 Then
    FM += 1000
End If
Dim FPS = 1000 / FM
Dim ETDFrame As New Bitmap(600, 600)
ETDFrame.image = Pixels().convertBMP

我知道这段代码不会起作用，但如果给出一个例子，我想要什么。我的目标是创建一个新的位图并编辑所有像素超快，足够快的3D游戏... < / p>

Answer 1

目前还不清楚你要做什么。看起来好像是在尝试将.jpg转换为.bmp。如果是这样，您只需调用Image类的.Save方法：

'Load the bitmap
Dim bm As Bitmap = Image.FromFile("C:\Users\Noah\Desktop\graphics\Grass.jpg")
'Save as .bmp
bm.Save("C:\Users\Noah\Desktop\graphics\Grass.bmp", System.Drawing.Imaging.ImageFormat.Bmp)

如果您确实需要使用像素，那么使用GetPixel和SetPixel将会太慢。您需要使用LockBits直接处理位图数据。像这样：

Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices

Private Sub DoGraphics()
    Dim x As Integer
    Dim y As Integer

    'PixelSize is 3 bytes for a 24bpp Argb image.
    'Change this value appropriately
    Dim PixelSize As Integer = 3

    'Load the bitmap
    Dim bm As Bitmap = Image.FromFile("C:\Users\Noah\Desktop\graphics\Grass.jpg")

    'lock the entire bitmap for editing
    'You can change the rectangle to specify different parts of the image if needed.
    Dim bmData As BitmapData = bm.LockBits(New Rectangle(0, 0, bm.Width, bm.Height), System.Drawing.Imaging.ImageLockMode.ReadWrite, bm.PixelFormat)

    'Declare empty Color array
    Dim pixels(bm.Width - 1, bm.Height - 1) As Color

    'loop through the locked area of the bitmap.
    For x = 0 To bmData.Width - 1
        For y = 0 To bmData.Height - 1
            'Get the various color offset locations for each pixel.
            'This calculation is for a 24bpp rgb bitmap
            Dim blueOfs As Integer = (bmData.Stride * x) + (PixelSize * y)
            Dim greenOfs As Integer = blueOfs + 1
            Dim redOfs As Integer = greenOfs + 1

            'Read the value for each color component for each pixel
            Dim red As Integer = Marshal.ReadByte(bmData.Scan0, redOfs)
            Dim green As Integer = Marshal.ReadByte(bmData.Scan0, greenOfs)
            Dim blue As Integer = Marshal.ReadByte(bmData.Scan0, blueOfs)

            'Create a Color structure from each color component of the pixel
            'and store it in the array
            pixels(x, y) = Color.FromArgb(red, green, blue)
        Next
    Next

    'Do something to the pixels array here:
    For x = 0 To bmData.Width - 1
        For y = 0 To bmData.Height - 1
            pixels(x, y) = Color.Red
        Next
    Next

    'Update the bitmap from the pixels array
    For x = 0 To bmData.Width - 1
        For y = 0 To bmData.Height - 1
            'Get the various color offset locations for each pixel.
            'This calculation is for a 24bpp rgb bitmap
            Dim blueOfs As Integer = (bmData.Stride * x) + (PixelSize * y)
            Dim greenOfs As Integer = blueOfs + 1
            Dim redOfs As Integer = greenOfs + 1

            'Set each component of the pixel
            'There are 3 bytes that make up each pixel (24bpp rgb)
            Marshal.WriteByte(bmData.Scan0, blueOfs, pixels(x, y).B)
            Marshal.WriteByte(bmData.Scan0, greenOfs, pixels(x,y).G)
            Marshal.WriteByte(bmData.Scan0, redOfs, pixels(x,y).R)

        Next
    Next

    'Important!
    bm.UnlockBits(bmData)

    'Save the updated bitmap
    bm.Save("C:\Users\Noah\Desktop\graphics\Grass.bmp", System.Drawing.Imaging.ImageFormat.Bmp)

End Sub

我希望这会有所帮助。

更新：我已更新代码以显示更改像素值。

Answer 2

不幸的是，Bitmap类的属性没有返回所有像素颜色的数组/列表，因此您无法一次性设置它们。The Microsoft documentation page实际上提供了示例代码在两个嵌套循环中获取和设置像素颜色，就像你已经在做的那样。

如果您的最终目标是存储像素信息以传递给另一个Bitmap，我建议the Clone method。不要花费时间和精力将数据提取到您自己的格式，而只需使用已经提供的数据。预定义的方法几乎总是最有效的，因此这应该是您表现最好的选择。

如果你真的必须将颜色存储在一个数组中，那么你必须编写一个循环遍历每种颜色的方法，并一次使用SetPixel一个像素。这听起来就像你现在正在做的那样，所以这不会节省任何时间。

如何创建一个位数组并将它们转换为位图VB？

2 个答案: