Source file src/image/image_test.go

Documentation: image

		 1  // Copyright 2011 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package image
		 6  
		 7  import (
		 8  	"image/color"
		 9  	"image/color/palette"
		10  	"testing"
		11  )
		12  
		13  type image interface {
		14  	Image
		15  	Opaque() bool
		16  	Set(int, int, color.Color)
		17  	SubImage(Rectangle) Image
		18  }
		19  
		20  func cmp(cm color.Model, c0, c1 color.Color) bool {
		21  	r0, g0, b0, a0 := cm.Convert(c0).RGBA()
		22  	r1, g1, b1, a1 := cm.Convert(c1).RGBA()
		23  	return r0 == r1 && g0 == g1 && b0 == b1 && a0 == a1
		24  }
		25  
		26  var testImages = []struct {
		27  	name	string
		28  	image func() image
		29  }{
		30  	{"rgba", func() image { return NewRGBA(Rect(0, 0, 10, 10)) }},
		31  	{"rgba64", func() image { return NewRGBA64(Rect(0, 0, 10, 10)) }},
		32  	{"nrgba", func() image { return NewNRGBA(Rect(0, 0, 10, 10)) }},
		33  	{"nrgba64", func() image { return NewNRGBA64(Rect(0, 0, 10, 10)) }},
		34  	{"alpha", func() image { return NewAlpha(Rect(0, 0, 10, 10)) }},
		35  	{"alpha16", func() image { return NewAlpha16(Rect(0, 0, 10, 10)) }},
		36  	{"gray", func() image { return NewGray(Rect(0, 0, 10, 10)) }},
		37  	{"gray16", func() image { return NewGray16(Rect(0, 0, 10, 10)) }},
		38  	{"paletted", func() image {
		39  		return NewPaletted(Rect(0, 0, 10, 10), color.Palette{
		40  			Transparent,
		41  			Opaque,
		42  		})
		43  	}},
		44  }
		45  
		46  func TestImage(t *testing.T) {
		47  	for _, tc := range testImages {
		48  		m := tc.image()
		49  		if !Rect(0, 0, 10, 10).Eq(m.Bounds()) {
		50  			t.Errorf("%T: want bounds %v, got %v", m, Rect(0, 0, 10, 10), m.Bounds())
		51  			continue
		52  		}
		53  		if !cmp(m.ColorModel(), Transparent, m.At(6, 3)) {
		54  			t.Errorf("%T: at (6, 3), want a zero color, got %v", m, m.At(6, 3))
		55  			continue
		56  		}
		57  		m.Set(6, 3, Opaque)
		58  		if !cmp(m.ColorModel(), Opaque, m.At(6, 3)) {
		59  			t.Errorf("%T: at (6, 3), want a non-zero color, got %v", m, m.At(6, 3))
		60  			continue
		61  		}
		62  		if !m.SubImage(Rect(6, 3, 7, 4)).(image).Opaque() {
		63  			t.Errorf("%T: at (6, 3) was not opaque", m)
		64  			continue
		65  		}
		66  		m = m.SubImage(Rect(3, 2, 9, 8)).(image)
		67  		if !Rect(3, 2, 9, 8).Eq(m.Bounds()) {
		68  			t.Errorf("%T: sub-image want bounds %v, got %v", m, Rect(3, 2, 9, 8), m.Bounds())
		69  			continue
		70  		}
		71  		if !cmp(m.ColorModel(), Opaque, m.At(6, 3)) {
		72  			t.Errorf("%T: sub-image at (6, 3), want a non-zero color, got %v", m, m.At(6, 3))
		73  			continue
		74  		}
		75  		if !cmp(m.ColorModel(), Transparent, m.At(3, 3)) {
		76  			t.Errorf("%T: sub-image at (3, 3), want a zero color, got %v", m, m.At(3, 3))
		77  			continue
		78  		}
		79  		m.Set(3, 3, Opaque)
		80  		if !cmp(m.ColorModel(), Opaque, m.At(3, 3)) {
		81  			t.Errorf("%T: sub-image at (3, 3), want a non-zero color, got %v", m, m.At(3, 3))
		82  			continue
		83  		}
		84  		// Test that taking an empty sub-image starting at a corner does not panic.
		85  		m.SubImage(Rect(0, 0, 0, 0))
		86  		m.SubImage(Rect(10, 0, 10, 0))
		87  		m.SubImage(Rect(0, 10, 0, 10))
		88  		m.SubImage(Rect(10, 10, 10, 10))
		89  	}
		90  }
		91  
		92  func TestNewXxxBadRectangle(t *testing.T) {
		93  	// call calls f(r) and reports whether it ran without panicking.
		94  	call := func(f func(Rectangle), r Rectangle) (ok bool) {
		95  		defer func() {
		96  			if recover() != nil {
		97  				ok = false
		98  			}
		99  		}()
	 100  		f(r)
	 101  		return true
	 102  	}
	 103  
	 104  	testCases := []struct {
	 105  		name string
	 106  		f		func(Rectangle)
	 107  	}{
	 108  		{"RGBA", func(r Rectangle) { NewRGBA(r) }},
	 109  		{"RGBA64", func(r Rectangle) { NewRGBA64(r) }},
	 110  		{"NRGBA", func(r Rectangle) { NewNRGBA(r) }},
	 111  		{"NRGBA64", func(r Rectangle) { NewNRGBA64(r) }},
	 112  		{"Alpha", func(r Rectangle) { NewAlpha(r) }},
	 113  		{"Alpha16", func(r Rectangle) { NewAlpha16(r) }},
	 114  		{"Gray", func(r Rectangle) { NewGray(r) }},
	 115  		{"Gray16", func(r Rectangle) { NewGray16(r) }},
	 116  		{"CMYK", func(r Rectangle) { NewCMYK(r) }},
	 117  		{"Paletted", func(r Rectangle) { NewPaletted(r, color.Palette{color.Black, color.White}) }},
	 118  		{"YCbCr", func(r Rectangle) { NewYCbCr(r, YCbCrSubsampleRatio422) }},
	 119  		{"NYCbCrA", func(r Rectangle) { NewNYCbCrA(r, YCbCrSubsampleRatio444) }},
	 120  	}
	 121  
	 122  	for _, tc := range testCases {
	 123  		// Calling NewXxx(r) should fail (panic, since NewXxx doesn't return an
	 124  		// error) unless r's width and height are both non-negative.
	 125  		for _, negDx := range []bool{false, true} {
	 126  			for _, negDy := range []bool{false, true} {
	 127  				r := Rectangle{
	 128  					Min: Point{15, 28},
	 129  					Max: Point{16, 29},
	 130  				}
	 131  				if negDx {
	 132  					r.Max.X = 14
	 133  				}
	 134  				if negDy {
	 135  					r.Max.Y = 27
	 136  				}
	 137  
	 138  				got := call(tc.f, r)
	 139  				want := !negDx && !negDy
	 140  				if got != want {
	 141  					t.Errorf("New%s: negDx=%t, negDy=%t: got %t, want %t",
	 142  						tc.name, negDx, negDy, got, want)
	 143  				}
	 144  			}
	 145  		}
	 146  
	 147  		// Passing a Rectangle whose width and height is MaxInt should also fail
	 148  		// (panic), due to overflow.
	 149  		{
	 150  			zeroAsUint := uint(0)
	 151  			maxUint := zeroAsUint - 1
	 152  			maxInt := int(maxUint / 2)
	 153  			got := call(tc.f, Rectangle{
	 154  				Min: Point{0, 0},
	 155  				Max: Point{maxInt, maxInt},
	 156  			})
	 157  			if got {
	 158  				t.Errorf("New%s: overflow: got ok, want !ok", tc.name)
	 159  			}
	 160  		}
	 161  	}
	 162  }
	 163  
	 164  func Test16BitsPerColorChannel(t *testing.T) {
	 165  	testColorModel := []color.Model{
	 166  		color.RGBA64Model,
	 167  		color.NRGBA64Model,
	 168  		color.Alpha16Model,
	 169  		color.Gray16Model,
	 170  	}
	 171  	for _, cm := range testColorModel {
	 172  		c := cm.Convert(color.RGBA64{0x1234, 0x1234, 0x1234, 0x1234}) // Premultiplied alpha.
	 173  		r, _, _, _ := c.RGBA()
	 174  		if r != 0x1234 {
	 175  			t.Errorf("%T: want red value 0x%04x got 0x%04x", c, 0x1234, r)
	 176  			continue
	 177  		}
	 178  	}
	 179  	testImage := []image{
	 180  		NewRGBA64(Rect(0, 0, 10, 10)),
	 181  		NewNRGBA64(Rect(0, 0, 10, 10)),
	 182  		NewAlpha16(Rect(0, 0, 10, 10)),
	 183  		NewGray16(Rect(0, 0, 10, 10)),
	 184  	}
	 185  	for _, m := range testImage {
	 186  		m.Set(1, 2, color.NRGBA64{0xffff, 0xffff, 0xffff, 0x1357}) // Non-premultiplied alpha.
	 187  		r, _, _, _ := m.At(1, 2).RGBA()
	 188  		if r != 0x1357 {
	 189  			t.Errorf("%T: want red value 0x%04x got 0x%04x", m, 0x1357, r)
	 190  			continue
	 191  		}
	 192  	}
	 193  }
	 194  
	 195  func TestRGBA64Image(t *testing.T) {
	 196  	// memset sets every element of s to v.
	 197  	memset := func(s []byte, v byte) {
	 198  		for i := range s {
	 199  			s[i] = v
	 200  		}
	 201  	}
	 202  
	 203  	r := Rect(0, 0, 3, 2)
	 204  	testCases := []Image{
	 205  		NewAlpha(r),
	 206  		NewAlpha16(r),
	 207  		NewCMYK(r),
	 208  		NewGray(r),
	 209  		NewGray16(r),
	 210  		NewNRGBA(r),
	 211  		NewNRGBA64(r),
	 212  		NewNYCbCrA(r, YCbCrSubsampleRatio444),
	 213  		NewPaletted(r, palette.Plan9),
	 214  		NewRGBA(r),
	 215  		NewRGBA64(r),
	 216  		NewUniform(color.RGBA64{}),
	 217  		NewYCbCr(r, YCbCrSubsampleRatio444),
	 218  		r,
	 219  	}
	 220  	for _, tc := range testCases {
	 221  		switch tc := tc.(type) {
	 222  		// Most of the concrete image types in the testCases implement the
	 223  		// draw.RGBA64Image interface: they have a SetRGBA64 method. We use an
	 224  		// interface literal here, instead of importing "image/draw", to avoid
	 225  		// an import cycle.
	 226  		//
	 227  		// The YCbCr and NYCbCrA types are special-cased. Chroma subsampling
	 228  		// means that setting one pixel can modify neighboring pixels. They
	 229  		// don't have Set or SetRGBA64 methods because that side effect could
	 230  		// be surprising. Here, we just memset the channel buffers instead.
	 231  		//
	 232  		// The Uniform and Rectangle types are also special-cased, as they
	 233  		// don't have a Set or SetRGBA64 method.
	 234  		case interface {
	 235  			SetRGBA64(x, y int, c color.RGBA64)
	 236  		}:
	 237  			tc.SetRGBA64(1, 1, color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF})
	 238  
	 239  		case *NYCbCrA:
	 240  			memset(tc.YCbCr.Y, 0x77)
	 241  			memset(tc.YCbCr.Cb, 0x88)
	 242  			memset(tc.YCbCr.Cr, 0x99)
	 243  			memset(tc.A, 0xAA)
	 244  
	 245  		case *Uniform:
	 246  			tc.C = color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF}
	 247  
	 248  		case *YCbCr:
	 249  			memset(tc.Y, 0x77)
	 250  			memset(tc.Cb, 0x88)
	 251  			memset(tc.Cr, 0x99)
	 252  
	 253  		case Rectangle:
	 254  			// No-op. Rectangle pixels' colors are immutable. They're always
	 255  			// color.Opaque.
	 256  
	 257  		default:
	 258  			t.Errorf("could not initialize pixels for %T", tc)
	 259  			continue
	 260  		}
	 261  
	 262  		// Check that RGBA64At(x, y) is equivalent to At(x, y).RGBA().
	 263  		rgba64Image, ok := tc.(RGBA64Image)
	 264  		if !ok {
	 265  			t.Errorf("%T is not an RGBA64Image", tc)
	 266  			continue
	 267  		}
	 268  		got := rgba64Image.RGBA64At(1, 1)
	 269  		wantR, wantG, wantB, wantA := tc.At(1, 1).RGBA()
	 270  		if (uint32(got.R) != wantR) || (uint32(got.G) != wantG) ||
	 271  			(uint32(got.B) != wantB) || (uint32(got.A) != wantA) {
	 272  			t.Errorf("%T:\ngot	(0x%04X, 0x%04X, 0x%04X, 0x%04X)\n"+
	 273  				"want (0x%04X, 0x%04X, 0x%04X, 0x%04X)", tc,
	 274  				got.R, got.G, got.B, got.A,
	 275  				wantR, wantG, wantB, wantA)
	 276  			continue
	 277  		}
	 278  	}
	 279  }
	 280  
	 281  func BenchmarkAt(b *testing.B) {
	 282  	for _, tc := range testImages {
	 283  		b.Run(tc.name, func(b *testing.B) {
	 284  			m := tc.image()
	 285  			b.ReportAllocs()
	 286  			b.ResetTimer()
	 287  			for i := 0; i < b.N; i++ {
	 288  				m.At(4, 5)
	 289  			}
	 290  		})
	 291  	}
	 292  }
	 293  
	 294  func BenchmarkSet(b *testing.B) {
	 295  	c := color.Gray{0xff}
	 296  	for _, tc := range testImages {
	 297  		b.Run(tc.name, func(b *testing.B) {
	 298  			m := tc.image()
	 299  			b.ReportAllocs()
	 300  			b.ResetTimer()
	 301  			for i := 0; i < b.N; i++ {
	 302  				m.Set(4, 5, c)
	 303  			}
	 304  		})
	 305  	}
	 306  }
	 307  
	 308  func BenchmarkRGBAAt(b *testing.B) {
	 309  	m := NewRGBA(Rect(0, 0, 10, 10))
	 310  	b.ResetTimer()
	 311  
	 312  	for i := 0; i < b.N; i++ {
	 313  		m.RGBAAt(4, 5)
	 314  	}
	 315  }
	 316  
	 317  func BenchmarkRGBASetRGBA(b *testing.B) {
	 318  	m := NewRGBA(Rect(0, 0, 10, 10))
	 319  	c := color.RGBA{0xff, 0xff, 0xff, 0x13}
	 320  	b.ResetTimer()
	 321  
	 322  	for i := 0; i < b.N; i++ {
	 323  		m.SetRGBA(4, 5, c)
	 324  	}
	 325  }
	 326  
	 327  func BenchmarkRGBA64At(b *testing.B) {
	 328  	m := NewRGBA64(Rect(0, 0, 10, 10))
	 329  	b.ResetTimer()
	 330  
	 331  	for i := 0; i < b.N; i++ {
	 332  		m.RGBA64At(4, 5)
	 333  	}
	 334  }
	 335  
	 336  func BenchmarkRGBA64SetRGBA64(b *testing.B) {
	 337  	m := NewRGBA64(Rect(0, 0, 10, 10))
	 338  	c := color.RGBA64{0xffff, 0xffff, 0xffff, 0x1357}
	 339  	b.ResetTimer()
	 340  
	 341  	for i := 0; i < b.N; i++ {
	 342  		m.SetRGBA64(4, 5, c)
	 343  	}
	 344  }
	 345  
	 346  func BenchmarkNRGBAAt(b *testing.B) {
	 347  	m := NewNRGBA(Rect(0, 0, 10, 10))
	 348  	b.ResetTimer()
	 349  
	 350  	for i := 0; i < b.N; i++ {
	 351  		m.NRGBAAt(4, 5)
	 352  	}
	 353  }
	 354  
	 355  func BenchmarkNRGBASetNRGBA(b *testing.B) {
	 356  	m := NewNRGBA(Rect(0, 0, 10, 10))
	 357  	c := color.NRGBA{0xff, 0xff, 0xff, 0x13}
	 358  	b.ResetTimer()
	 359  
	 360  	for i := 0; i < b.N; i++ {
	 361  		m.SetNRGBA(4, 5, c)
	 362  	}
	 363  }
	 364  
	 365  func BenchmarkNRGBA64At(b *testing.B) {
	 366  	m := NewNRGBA64(Rect(0, 0, 10, 10))
	 367  	b.ResetTimer()
	 368  
	 369  	for i := 0; i < b.N; i++ {
	 370  		m.NRGBA64At(4, 5)
	 371  	}
	 372  }
	 373  
	 374  func BenchmarkNRGBA64SetNRGBA64(b *testing.B) {
	 375  	m := NewNRGBA64(Rect(0, 0, 10, 10))
	 376  	c := color.NRGBA64{0xffff, 0xffff, 0xffff, 0x1357}
	 377  	b.ResetTimer()
	 378  
	 379  	for i := 0; i < b.N; i++ {
	 380  		m.SetNRGBA64(4, 5, c)
	 381  	}
	 382  }
	 383  
	 384  func BenchmarkAlphaAt(b *testing.B) {
	 385  	m := NewAlpha(Rect(0, 0, 10, 10))
	 386  	b.ResetTimer()
	 387  
	 388  	for i := 0; i < b.N; i++ {
	 389  		m.AlphaAt(4, 5)
	 390  	}
	 391  }
	 392  
	 393  func BenchmarkAlphaSetAlpha(b *testing.B) {
	 394  	m := NewAlpha(Rect(0, 0, 10, 10))
	 395  	c := color.Alpha{0x13}
	 396  	b.ResetTimer()
	 397  
	 398  	for i := 0; i < b.N; i++ {
	 399  		m.SetAlpha(4, 5, c)
	 400  	}
	 401  }
	 402  
	 403  func BenchmarkAlpha16At(b *testing.B) {
	 404  	m := NewAlpha16(Rect(0, 0, 10, 10))
	 405  	b.ResetTimer()
	 406  
	 407  	for i := 0; i < b.N; i++ {
	 408  		m.Alpha16At(4, 5)
	 409  	}
	 410  }
	 411  
	 412  func BenchmarkAlphaSetAlpha16(b *testing.B) {
	 413  	m := NewAlpha16(Rect(0, 0, 10, 10))
	 414  	c := color.Alpha16{0x13}
	 415  	b.ResetTimer()
	 416  
	 417  	for i := 0; i < b.N; i++ {
	 418  		m.SetAlpha16(4, 5, c)
	 419  	}
	 420  }
	 421  
	 422  func BenchmarkGrayAt(b *testing.B) {
	 423  	m := NewGray(Rect(0, 0, 10, 10))
	 424  	b.ResetTimer()
	 425  
	 426  	for i := 0; i < b.N; i++ {
	 427  		m.GrayAt(4, 5)
	 428  	}
	 429  }
	 430  
	 431  func BenchmarkGraySetGray(b *testing.B) {
	 432  	m := NewGray(Rect(0, 0, 10, 10))
	 433  	c := color.Gray{0x13}
	 434  	b.ResetTimer()
	 435  
	 436  	for i := 0; i < b.N; i++ {
	 437  		m.SetGray(4, 5, c)
	 438  	}
	 439  }
	 440  
	 441  func BenchmarkGray16At(b *testing.B) {
	 442  	m := NewGray16(Rect(0, 0, 10, 10))
	 443  	b.ResetTimer()
	 444  
	 445  	for i := 0; i < b.N; i++ {
	 446  		m.Gray16At(4, 5)
	 447  	}
	 448  }
	 449  
	 450  func BenchmarkGraySetGray16(b *testing.B) {
	 451  	m := NewGray16(Rect(0, 0, 10, 10))
	 452  	c := color.Gray16{0x13}
	 453  	b.ResetTimer()
	 454  
	 455  	for i := 0; i < b.N; i++ {
	 456  		m.SetGray16(4, 5, c)
	 457  	}
	 458  }
	 459  

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