Fix missing "using PixelFormats" line in Readme example

[tonygameplan]

Prerequisites

• I have written a descriptive pull-request title
• I have verified that there are no overlapping pull-requests open
• I have verified that I am following matches the existing coding patterns and practice as demonstrated in the repository. These follow strict Stylecop rules 👮.
• (N/A) I have provided test coverage for my change (where applicable)

Description

"" does not appear to be defined without the "using SixLabors.ImageSharp.PixelFormats;" line and causes a "The type or namespace name 'Rgba32' could not be found (are you missing a using directive or an assembly reference?) (CS0246)" error to occur. This change fixes the issue by adding the PixelFormats line to the initial dependencies section.

[CLAassistant]

All committers have signed the CLA.

[JimBobSquarePants]

Thanks for this. We actually need to change the sample slightly though since we introduced the new non generic syntax in #904.

The sample should be:

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Processing;

// Image.Load(string path) is a shortcut for the default type. 
// Other pixel formats use Image.Load<TPixel>(string path))
using (Image image = Image.Load("foo.jpg"))
{
    image.Mutate(x => x
         .Resize(image.Width / 2, image.Height / 2)
         .Grayscale());
    image.Save("bar.jpg"); // Automatic encoder selected based on extension.
}

[codecov]

Codecov Report

Merging #921 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #921   +/-   ##
=======================================
  Coverage   89.26%   89.26%           
=======================================
  Files        1076     1076           
  Lines       47210    47210           
  Branches     3295     3295           
=======================================
  Hits        42141    42141           
  Misses       4366     4366           
  Partials      703      703

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 07ec651...75daccf. Read the comment docs.

[codecov]

Codecov Report

Merging #921 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #921   +/-   ##
=======================================
  Coverage   89.26%   89.26%           
=======================================
  Files        1077     1077           
  Lines       47230    47230           
  Branches     3320     3320           
=======================================
  Hits        42159    42159           
  Misses       4367     4367           
  Partials      704      704

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8107587...52ca867. Read the comment docs.

[antonfirsov]

It could be a source of confusion to use the Image image = ... declaration here, since the class is only present in the nightlies at the moment. Maybe we should replace it with var for now.

[JimBobSquarePants]

@antonfirsov You're making me twitchy reading that 😄 var without an explicit declaration on the right hand side. Naughty!

[antonfirsov]

@antonfirsov You're making me twitchy reading that 😄 var without an explicit declaration on the right hand side. Naughty!

Not if you look at it as a sample code for Nightly / RC1 versions 😄 It might be also an option to merge this PR as is, and fix the samples before releasing RC1.

[JimBobSquarePants]

Let's do that then. @tonygameplan please ignore all our chatter; I'll get this updated and merged now. Cheers! 👍