Decode Portable PixMap images in .NET8.
Header format
P<x>
# comment
<width> <height>
<max>
Example
P6
640 480
65535
Kinds
| Magic Number | Type | Extension | Image Type | Encoding |
|---|---|---|---|---|
| P1 | PBM | .pbm | B/W | ASCII |
| P2 | PGM | .pgm | Gray | ASCII |
| P3 | PPM | .ppm | RGB | ASCII |
| P4 | PBM | .pbm | B/W | Binary |
| P5 | PGM | .pgm | Gray | Binary |
| P6 | PPM | .ppm | RGB | Binary |
// Read pbm/pgm/ppm image
IPpmImage ppmImage = await PpmImageReader.ReadAsync(@"C:\image.ppm");
// Read raw image
(int width, int height, int pixelBits) = (640, 480, 12);
IImage rawImage1 = await RawImageReader.ReadAsync(@"C:\image1.raw", width, height, pixelBits);
// Read raw image with stride/Offset
(int stride, int pixelOffset) = (643, 0x10);
IImage rawImage2 = await RawImageReader.ReadAsync(@"C:\image2.raw", width, height, pixelBits, stride, pixelOffset);BenchmarkDotNet v0.13.12, Windows 11 (10.0.22621.3672/22H2/2022Update/SunValley2) AMD Ryzen 7 PRO 4750GE with Radeon Graphics, 1 CPU, 16 logical and 8 physical cores .NET SDK 8.0.300 [Host] : .NET 8.0.5 (8.0.524.21615), X64 RyuJIT AVX2 [AttachedDebugger] DefaultJob : .NET 8.0.5 (8.0.524.21615), X64 RyuJIT AVX2
| Method | Filename | Mean | Error | StdDev | Gen0 | Gen1 | Gen2 | Allocated |
|---|---|---|---|---|---|---|---|---|
| ReadHeader | P1-200x200.pbm | 69.76 us | 0.303 us | 0.283 us | 3.9063 | - | - | 7.46 KB |
| ReadImage | P1-200x200.pbm | 345.65 us | 4.595 us | 4.073 us | 24.9023 | - | - | 47.38 KB |
| ReadHeader | P2-300x200.pgm | 72.01 us | 1.324 us | 1.238 us | 3.9063 | - | - | 7.44 KB |
| ReadImage | P2-300x200.pgm | 842.29 us | 4.745 us | 4.439 us | 34.1797 | - | - | 67.02 KB |
| ReadHeader | P3-300x300.ppm | 69.91 us | 0.333 us | 0.295 us | 3.9063 | - | - | 7.63 KB |
| ReadImage | P3-300x300.ppm | 5,275.37 us | 16.544 us | 15.475 us | 78.1250 | 78.1250 | 78.1250 | 272.26 KB |
| ReadHeader | P4-305x400.pbm | 73.66 us | 0.300 us | 0.266 us | 3.6621 | - | - | 7.12 KB |
| ReadImage | P4-305x400.pbm | 194.32 us | 1.287 us | 1.141 us | 38.3301 | 38.3301 | 38.3301 | 127.17 KB |
| ReadHeader | P5-300x246.pgm | 69.91 us | 1.326 us | 1.419 us | 3.6621 | - | - | 7.26 KB |
| ReadImage | P5-300x246.pgm | 101.39 us | 0.581 us | 0.543 us | 41.5039 | - | - | 80.3 KB |
| ReadHeader | P6-640x426.ppm | 72.04 us | 0.450 us | 0.399 us | 3.6621 | - | - | 7.26 KB |
| ReadImage | P6-640x426.ppm | 455.97 us | 3.875 us | 3.625 us | 249.5117 | 249.5117 | 249.5117 | 807.15 KB |