public Inner()
{
code = new SIMDcode(Options.Default,
_ =>
{
// BGRx to Y, fast but not super accurate
// assumes there is no row-padding in the input (a Sytem.Drawing.Bitmap with Format32bppRgb satisfies this requirement)
// assumes there is no row-padding in the output (ensure width is multiple of 4 or write it into an array)
// assumes the image has at least 16 pixels or is padded up to such a size (64 bytes in, 16 bytes out)
// uses approximate Y weights from JPEG in Q7:
// Wr = 0.299 -> 38/128 (0.296875)
// Wg = 0.587 -> 75/128 (0.5859375)
// Wb = 0.114 -> 15/128 (0.1171875)
// Q8 doesn't work because pmaddubsw's second operand is *signed* bytes and Wg would be 150
// Q7 would not work in general because of the saturating addition, but the maximum sum
// that can occur with these weights is (38+75)*255=28815 which fits in a signed word.
// Result is rounded by adding 0.5, then truncated.
// _mm_packus_epi16 applies unsigned clipping but its input is never out of range.
byte rw = 38, gw = 75, bw = 15;
var dst = _.arg(0);
var src = _.arg(1);
var len = _.arg(2);
var weight = _._mm_setr_epi8(bw, gw, rw, 0, bw, gw, rw, 0, bw, gw, rw, 0, bw, gw, rw, 0);
var rounding = _._mm_set1_epi16(64);
_.repeat(len, 16);
{
var p0 = _._mm_loadu_si128(src);
var p1 = _._mm_loadu_si128(src, 16);
var p2 = _._mm_loadu_si128(src, 32);
var p3 = _._mm_loadu_si128(src, 48);
var t0 = _._mm_maddubs_epi16(p0, weight);
var t1 = _._mm_maddubs_epi16(p1, weight);
var t2 = _._mm_maddubs_epi16(p2, weight);
var t3 = _._mm_maddubs_epi16(p3, weight);
_.assign(src, _.add(src, 64));
t0 = _._mm_hadd_epi16(t0, t1);
t1 = _._mm_hadd_epi16(t2, t3);
t0 = _._mm_add_epi16(t0, rounding);
t1 = _._mm_add_epi16(t1, rounding);
t0 = _._mm_srli_epi16(t0, 7);
t1 = _._mm_srli_epi16(t1, 7);
t0 = _._mm_packus_epi16(t0, t1);
_._mm_storeu_si128(dst, t0);
_.assign(dst, _.add(dst, 16));
}
_.endrepeat();
});
Rgb32_to_Gray = code.GetDelegate <ArrayTransform>(0);
}
static void Main(string[] args)
{
var opts = Options.Default;
opts.AVX2 = false;
//opts.breakAtFunctionEntry = true;
SIMDcode s = new SIMDcode(opts, _ =>
{
// BGRx to Y, fast but not super accurate
// using approximate Y weights from JPEG in Q7:
// Wr = 0.299 -> 38/128 (0.296875)
// Wg = 0.587 -> 75/128 (0.5859375)
// Wb = 0.114 -> 15/128 (0.1171875)
// Q8 would be more complicated because pmaddubsw's second operand is *signed* bytes and Wg would be 150
// Q7 would not work in general because of the saturating addition, but the maximum sum
// that can occur with these weights is (38+75)*255=28815 which fits in a signed word.
// Result is rounded by adding 0.5, then truncated.
// _mm_packus_epi16 applies unsigned clipping but its input is never out of range.
byte rw = 38, gw = 75, bw = 15;
var dst = _.arg(0);
var src = _.arg(1);
var len = _.arg(2);
var weight = _._mm_setr_epi8(bw, gw, rw, 0, bw, gw, rw, 0, bw, gw, rw, 0, bw, gw, rw, 0);
var rounding = _._mm_set1_epi16(64);
_.repeat(len, 16);
{
var p0 = _._mm_loadu_si128(src);
var p1 = _._mm_loadu_si128(src, 16);
var p2 = _._mm_loadu_si128(src, 32);
var p3 = _._mm_loadu_si128(src, 48);
var t0 = _._mm_maddubs_epi16(p0, weight);
var t1 = _._mm_maddubs_epi16(p1, weight);
var t2 = _._mm_maddubs_epi16(p2, weight);
var t3 = _._mm_maddubs_epi16(p3, weight);
_.assign(src, _.add(src, 64));
t0 = _._mm_hadd_epi16(t0, t1);
t1 = _._mm_hadd_epi16(t2, t3);
t0 = _._mm_add_epi16(t0, rounding);
t1 = _._mm_add_epi16(t1, rounding);
t0 = _._mm_srli_epi16(t0, 7);
t1 = _._mm_srli_epi16(t1, 7);
t0 = _._mm_packus_epi16(t0, t1);
_._mm_storeu_si128(dst, t0);
_.assign(dst, _.add(dst, 16));
}
_.endrepeat();
}, _ =>
{
// upscale x2
var dst = _.arg(0);
var src = _.arg(1);
var width = _.arg(2);
var height = _.arg(3);
// upscale vertically
var prev = _._mm_setzero_si128();
_.repeat(width, 16);
{
var t0 = _._mm_loadu_si128(src);
//t3 = 0;
}
_.endrepeat();
});
Bitmap input = (Bitmap)Bitmap.FromFile(@"C:\Users\Harold\Pictures\Barns_grand_tetons.jpg");
Bitmap output = new Bitmap(input.Width, input.Height, System.Drawing.Imaging.PixelFormat.Format8bppIndexed);
var bdin = input.LockBits(new Rectangle(Point.Empty, input.Size), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
var bdout = output.LockBits(new Rectangle(Point.Empty, input.Size), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format8bppIndexed);
System.Drawing.Imaging.ColorPalette pal = output.Palette;
for (int i = 0; i < 256; i++)
{
pal.Entries[i] = Color.FromArgb(255, i, i, i);
}
output.Palette = pal;
var foo = s.GetDelegate <Foo>(0);
foo((uint *)bdout.Scan0, (uint *)bdin.Scan0, input.Width * input.Height);
input.UnlockBits(bdin);
output.UnlockBits(bdout);
output.Save(@"C:\Users\Harold\Pictures\Barns_grand_tetons_graytest.png", System.Drawing.Imaging.ImageFormat.Png);
return;
}
