Test qol fixes

tests/ImageSharp.Tests/Formats/Jpg/DCTTests.cs

@@ -52,16 +52,15 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
                 // Part of the IDCT calculations is fused into the quantization step
                 // We must multiply input block with adjusted no-quantization matrix
                 // before applying IDCT
+                // Dequantization using unit matrix - no values are upscaled
                 Block8x8F dequantMatrix = CreateBlockFromScalar(1);
 
-                // Dequantization using unit matrix - no values are upscaled
-                // as quant matrix is all 1's
                 // This step is needed to apply adjusting multipliers to the input block
                 FastFloatingPointDCT.AdjustToIDCT(ref dequantMatrix);
-                srcBlock.MultiplyInPlace(ref dequantMatrix);
 
                 // IDCT implementation tranforms blocks after transposition
                 srcBlock.TransposeInplace();
+                srcBlock.MultiplyInPlace(ref dequantMatrix);
 
                 // IDCT calculation
                 FastFloatingPointDCT.TransformIDCT(ref srcBlock);
@@ -86,16 +85,15 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
                 // Part of the IDCT calculations is fused into the quantization step
                 // We must multiply input block with adjusted no-quantization matrix
                 // before applying IDCT
+                // Dequantization using unit matrix - no values are upscaled
                 Block8x8F dequantMatrix = CreateBlockFromScalar(1);
 
-                // Dequantization using unit matrix - no values are upscaled
-                // as quant matrix is all 1's
                 // This step is needed to apply adjusting multipliers to the input block
                 FastFloatingPointDCT.AdjustToIDCT(ref dequantMatrix);
-                srcBlock.MultiplyInPlace(ref dequantMatrix);
 
                 // IDCT implementation tranforms blocks after transposition
                 srcBlock.TransposeInplace();
+                srcBlock.MultiplyInPlace(ref dequantMatrix);
 
                 // IDCT calculation
                 FastFloatingPointDCT.TransformIDCT(ref srcBlock);

tests/ImageSharp.Tests/Formats/Jpg/Utils/JpegFixture.cs

@@ -172,7 +172,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg.Utils
 
             bool failed = false;
 
-            for (int i = 0; i < 64; i++)
+            for (int i = 0; i < Block8x8F.Size; i++)
             {
                 float expected = a[i];
                 float actual = b[i];