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Optimize DibHelper a bit, now only needs one byte array instead of two (#348)

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This commit is contained in:
Carsten Schuette 2022-02-03 08:43:27 +01:00
commit fc804655a6
1 changed files with 26 additions and 26 deletions
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52
src/Greenshot.Base/Core/DibHelper.cs
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@ -23,9 +23,12 @@ namespace Greenshot.Base.Core
/// <returns>The image converted to DIB, in bytes.</returns>
public static byte[] ConvertToDib(Image image)
{
byte[] bm32bData;
byte[] fullImage;
int dataLength;
int width = image.Width;
int height = image.Height;
const int hdrSize = 0x28;
// Ensure image is 32bppARGB by painting it on a new 32bppARGB image.
using (var bm32b = ImageHelper.CreateEmptyLike(image, Color.Transparent, PixelFormat.Format32bppArgb))
{
@ -33,26 +36,40 @@ namespace Greenshot.Base.Core
{
graphics.DrawImage(image, new Rectangle(0, 0, bm32b.Width, bm32b.Height));
}
// Bitmap format has its lines reversed.
bm32b.RotateFlip(RotateFlipType.Rotate180FlipX);
bm32bData = GetImageData(bm32b, out var stride);
}
// BITMAPINFOHEADER struct for DIB.
uint hdrSize = 0x28;
var fullImage = new byte[hdrSize + 12 + bm32bData.Length];
var bitmapInfoHeader = MemoryMarshal.Cast<byte, BITMAPINFOHEADER>(fullImage.AsSpan());
// Copy bitmap data into a new byte array with additional space for BITMAPINFOHEADER
BitmapData bm32bBitmapData = null;
try
{
bm32bBitmapData = bm32b.LockBits(new Rectangle(0, 0, bm32b.Width, bm32b.Height), ImageLockMode.ReadOnly, bm32b.PixelFormat);
dataLength = bm32bBitmapData.Stride * bm32b.Height;
fullImage = new byte[hdrSize + 12 + dataLength];
Marshal.Copy(bm32bBitmapData.Scan0, fullImage, hdrSize + 12, dataLength);
}
finally
{
if (bm32bBitmapData != null)
{
bm32b.UnlockBits(bm32bBitmapData);
}
}
}
// BITMAPINFOHEADER struct for DIB.
var bitmapInfoHeader = MemoryMarshal.Cast<byte, BITMAPINFOHEADER>(fullImage.AsSpan());
bitmapInfoHeader[0].biSize = hdrSize;
bitmapInfoHeader[0].biWidth = width;
bitmapInfoHeader[0].biHeight = height;
bitmapInfoHeader[0].biPlanes = 1;
bitmapInfoHeader[0].biBitCount = 32;
bitmapInfoHeader[0].biCompression = BI_COMPRESSION.BI_BITFIELDS;
bitmapInfoHeader[0].biSizeImage = (uint)bm32bData.Length;
bitmapInfoHeader[0].biSizeImage = (uint)dataLength;
bitmapInfoHeader[0].biXPelsPerMeter = (int)(image.HorizontalResolution * 39.3701);
bitmapInfoHeader[0].biYPelsPerMeter = (int)(image.VerticalResolution * 39.3701);
// The aforementioned "BITFIELDS": colour masks applied to the Int32 pixel value to get the R, G and B values.
bitmapInfoHeader[0].bV5RedMask = 0x00FF0000;
bitmapInfoHeader[0].bV5GreenMask = 0x0000FF00;
@ -62,24 +79,7 @@ namespace Greenshot.Base.Core
//Int32 biClrUsed = 0;
//Int32 biClrImportant = 0;
Array.Copy(bm32bData, 0, fullImage, hdrSize + 12, bm32bData.Length);
return fullImage;
}
/// <summary>
/// Gets the raw bytes from an image.
/// </summary>
/// <param name="sourceImage">The image to get the bytes from.</param>
/// <param name="stride">Stride of the retrieved image data.</param>
/// <returns>The raw bytes of the image</returns>
public static byte[] GetImageData(Bitmap sourceImage, out int stride)
{
BitmapData sourceData = sourceImage.LockBits(new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), ImageLockMode.ReadOnly, sourceImage.PixelFormat);
stride = sourceData.Stride;
byte[] data = new byte[stride * sourceImage.Height];
Marshal.Copy(sourceData.Scan0, data, 0, data.Length);
sourceImage.UnlockBits(sourceData);
return data;
}
}
}