Avoid bounds checks

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/BlackIsZero16TiffColor{TPixel}.cs

@@ -34,10 +34,10 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             int offset = 0;
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
                 if (this.isBigEndian)
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ushort intensity = TiffUtils.ConvertToShortBigEndian(data.Slice(offset, 2));
                         offset += 2;
@@ -47,7 +47,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
                 }
                 else
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ushort intensity = TiffUtils.ConvertToShortLittleEndian(data.Slice(offset, 2));
                         offset += 2;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/BlackIsZero8TiffColor{TPixel}.cs

@@ -24,8 +24,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             var l8 = default(L8);
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     byte intensity = data[offset++];
                     pixelRow[x] = TiffUtils.ColorFromL8(l8, intensity, color);

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/BlackIsZeroTiffColor{TPixel}.cs

@@ -34,8 +34,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     int value = bitReader.ReadBits(this.bitsPerSample0);
                     float intensity = value / this.factor;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/PaletteTiffColor{TPixel}.cs

@@ -35,8 +35,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     int index = bitReader.ReadBits(this.bitsPerSample0);
                     pixelRow[x] = this.palette[index];

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/Rgb161616TiffColor{TPixel}.cs

@@ -35,11 +35,11 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
 
                 if (this.isBigEndian)
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ulong r = TiffUtils.ConvertToShortBigEndian(data.Slice(offset, 2));
                         offset += 2;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/Rgb16PlanarTiffColor{TPixel}.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Six Labors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using System.Buffers;
-using System.Numerics;
 using SixLabors.ImageSharp.Formats.Tiff.Utils;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.PixelFormats;
@@ -32,17 +32,17 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             var color = default(TPixel);
             color.FromVector4(TiffUtils.Vector4Default);
 
-            System.Span<byte> redData = data[0].GetSpan();
+            Span<byte> redData = data[0].GetSpan();
-            System.Span<byte> greenData = data[1].GetSpan();
+            Span<byte> greenData = data[1].GetSpan();
-            System.Span<byte> blueData = data[2].GetSpan();
+            Span<byte> blueData = data[2].GetSpan();
 
             int offset = 0;
             for (int y = top; y < top + height; y++)
             {
-                System.Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
                 if (this.isBigEndian)
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ulong r = TiffUtils.ConvertToShortBigEndian(redData.Slice(offset, 2));
                         ulong g = TiffUtils.ConvertToShortBigEndian(greenData.Slice(offset, 2));
@@ -55,7 +55,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
                 }
                 else
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ulong r = TiffUtils.ConvertToShortLittleEndian(redData.Slice(offset, 2));
                         ulong g = TiffUtils.ConvertToShortLittleEndian(greenData.Slice(offset, 2));

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/Rgb888TiffColor{TPixel}.cs

@@ -24,9 +24,9 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             var rgba = default(Rgba32);
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
 
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     byte r = data[offset++];
                     byte g = data[offset++];

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/RgbPlanarTiffColor{TPixel}.cs

@@ -58,8 +58,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     float r = rBitReader.ReadBits(this.bitsPerSampleR) / this.rFactor;
                     float g = gBitReader.ReadBits(this.bitsPerSampleG) / this.gFactor;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/RgbTiffColor{TPixel}.cs

@@ -47,8 +47,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     float r = bitReader.ReadBits(this.bitsPerSampleR) / this.rFactor;
                     float g = bitReader.ReadBits(this.bitsPerSampleG) / this.gFactor;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/WhiteIsZero16TiffColor{TPixel}.cs

@@ -34,10 +34,10 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             int offset = 0;
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
                 if (this.isBigEndian)
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ushort intensity = (ushort)(ushort.MaxValue - TiffUtils.ConvertToShortBigEndian(data.Slice(offset, 2)));
                         offset += 2;
@@ -47,7 +47,7 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
                 }
                 else
                 {
-                    for (int x = left; x < left + width; x++)
+                    for (int x = 0; x < pixelRow.Length; x++)
                     {
                         ushort intensity = (ushort)(ushort.MaxValue - TiffUtils.ConvertToShortLittleEndian(data.Slice(offset, 2)));
                         offset += 2;

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/WhiteIsZero8TiffColor{TPixel}.cs

@@ -24,8 +24,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
             var l8 = default(L8);
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     byte intensity = (byte)(255 - data[offset++]);
                     pixelRow[x] = TiffUtils.ColorFromL8(l8, intensity, color);

src/ImageSharp/Formats/Tiff/PhotometricInterpretation/WhiteIsZeroTiffColor{TPixel}.cs

@@ -34,8 +34,8 @@ namespace SixLabors.ImageSharp.Formats.Tiff.PhotometricInterpretation
 
             for (int y = top; y < top + height; y++)
             {
-                Span<TPixel> pixelRow = pixels.GetRowSpan(y);
+                Span<TPixel> pixelRow = pixels.GetRowSpan(y).Slice(left, width);
-                for (int x = left; x < left + width; x++)
+                for (int x = 0; x < pixelRow.Length; x++)
                 {
                     int value = bitReader.ReadBits(this.bitsPerSample0);
                     float intensity = 1.0f - (value / this.factor);