impl. image processing and rename update-sign option to update-json

Jpeg.cs

@@ -0,0 +1,42 @@
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Formats.Jpeg;
+using SixLabors.ImageSharp.PixelFormats;
+namespace RagePhoto.Cli;
+
+internal class Jpeg {
+
+    internal static Byte[] GetEmptyJpeg(PhotoFormat format, out Size size) {
+        size = format == PhotoFormat.GTA5 ? new(960, 536) : new(1920, 1080);
+        using Image<Rgb24> image = new(size.Width, size.Height);
+        image.ProcessPixelRows(static pixelAccessor => {
+            for (Int32 y = 0; y < pixelAccessor.Height; y++) {
+                Span<Rgb24> pixelRow = pixelAccessor.GetRowSpan(y);
+                for (Int32 x = 0; x < pixelRow.Length; x++) {
+                    pixelRow[x] = Color.Black;
+                }
+            }
+        });
+        using MemoryStream output = new();
+        image.SaveAsJpeg(output, new() {
+            Quality = 100,
+            ColorType = JpegEncodingColor.YCbCrRatio444
+        });
+        return output.ToArray();
+    }
+
+    internal static Byte[] GetJpeg(Stream stream, out Size size) {
+        using Image image = Image.Load(stream);
+        size = image.Size;
+        image.Metadata.ExifProfile = null;
+        using MemoryStream output = new();
+        image.SaveAsJpeg(output, new() {
+            Quality = 100,
+            ColorType = JpegEncodingColor.YCbCrRatio444
+        });
+        return output.ToArray();
+    }
+
+    internal static Size GetSize(ReadOnlySpan<Byte> jpeg) {
+        return Image.Identify(jpeg).Size;
+    }
+}