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| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include <algorithm> | |
| 6 #include <cmath> | |
| 7 #include <iomanip> | |
| 8 #include <vector> | |
| 9 | |
| 10 #include "base/basictypes.h" | |
| 11 #include "base/compiler_specific.h" | |
| 12 #include "base/files/file_util.h" | |
| 13 #include "base/strings/string_util.h" | |
| 14 #include "skia/ext/image_operations.h" | |
| 15 #include "testing/gtest/include/gtest/gtest.h" | |
| 16 #include "third_party/skia/include/core/SkBitmap.h" | |
| 17 #include "third_party/skia/include/core/SkRect.h" | |
| 18 #include "ui/gfx/codec/png_codec.h" | |
| 19 #include "ui/gfx/geometry/size.h" | |
| 20 | |
| 21 namespace { | |
| 22 | |
| 23 // Computes the average pixel value for the given range, inclusive. | |
| 24 uint32_t AveragePixel(const SkBitmap& bmp, | |
| 25 int x_min, int x_max, | |
| 26 int y_min, int y_max) { | |
| 27 float accum[4] = {0, 0, 0, 0}; | |
| 28 int count = 0; | |
| 29 for (int y = y_min; y <= y_max; y++) { | |
| 30 for (int x = x_min; x <= x_max; x++) { | |
| 31 uint32_t cur = *bmp.getAddr32(x, y); | |
| 32 accum[0] += SkColorGetB(cur); | |
| 33 accum[1] += SkColorGetG(cur); | |
| 34 accum[2] += SkColorGetR(cur); | |
| 35 accum[3] += SkColorGetA(cur); | |
| 36 count++; | |
| 37 } | |
| 38 } | |
| 39 | |
| 40 return SkColorSetARGB(static_cast<unsigned char>(accum[3] / count), | |
| 41 static_cast<unsigned char>(accum[2] / count), | |
| 42 static_cast<unsigned char>(accum[1] / count), | |
| 43 static_cast<unsigned char>(accum[0] / count)); | |
| 44 } | |
| 45 | |
| 46 // Computes the average pixel (/color) value for the given colors. | |
| 47 SkColor AveragePixel(const SkColor colors[], size_t color_count) { | |
| 48 float accum[4] = { 0.0f, 0.0f, 0.0f, 0.0f }; | |
| 49 for (size_t i = 0; i < color_count; ++i) { | |
| 50 const SkColor cur = colors[i]; | |
| 51 accum[0] += static_cast<float>(SkColorGetA(cur)); | |
| 52 accum[1] += static_cast<float>(SkColorGetR(cur)); | |
| 53 accum[2] += static_cast<float>(SkColorGetG(cur)); | |
| 54 accum[3] += static_cast<float>(SkColorGetB(cur)); | |
| 55 } | |
| 56 const SkColor average_color = | |
| 57 SkColorSetARGB(static_cast<uint8_t>(accum[0] / color_count), | |
| 58 static_cast<uint8_t>(accum[1] / color_count), | |
| 59 static_cast<uint8_t>(accum[2] / color_count), | |
| 60 static_cast<uint8_t>(accum[3] / color_count)); | |
| 61 return average_color; | |
| 62 } | |
| 63 | |
| 64 void PrintPixel(const SkBitmap& bmp, | |
| 65 int x_min, int x_max, | |
| 66 int y_min, int y_max) { | |
| 67 char str[128]; | |
| 68 | |
| 69 for (int y = y_min; y <= y_max; ++y) { | |
| 70 for (int x = x_min; x <= x_max; ++x) { | |
| 71 const uint32_t cur = *bmp.getAddr32(x, y); | |
| 72 base::snprintf(str, sizeof(str), "bmp[%d,%d] = %08X", x, y, cur); | |
| 73 ADD_FAILURE() << str; | |
| 74 } | |
| 75 } | |
| 76 } | |
| 77 | |
| 78 // Returns the euclidian distance between two RGBA colors interpreted | |
| 79 // as 4-components vectors. | |
| 80 // | |
| 81 // Notes: | |
| 82 // - This is a really poor definition of color distance. Yet it | |
| 83 // is "good enough" for our uses here. | |
| 84 // - More realistic measures like the various Delta E formulas defined | |
| 85 // by CIE are way more complex and themselves require the RGBA to | |
| 86 // to transformed into CIELAB (typically via sRGB first). | |
| 87 // - The static_cast<int> below are needed to avoid interpreting "negative" | |
| 88 // differences as huge positive values. | |
| 89 float ColorsEuclidianDistance(const SkColor a, const SkColor b) { | |
| 90 int b_int_diff = static_cast<int>(SkColorGetB(a) - SkColorGetB(b)); | |
| 91 int g_int_diff = static_cast<int>(SkColorGetG(a) - SkColorGetG(b)); | |
| 92 int r_int_diff = static_cast<int>(SkColorGetR(a) - SkColorGetR(b)); | |
| 93 int a_int_diff = static_cast<int>(SkColorGetA(a) - SkColorGetA(b)); | |
| 94 | |
| 95 float b_float_diff = static_cast<float>(b_int_diff); | |
| 96 float g_float_diff = static_cast<float>(g_int_diff); | |
| 97 float r_float_diff = static_cast<float>(r_int_diff); | |
| 98 float a_float_diff = static_cast<float>(a_int_diff); | |
| 99 | |
| 100 return sqrtf((b_float_diff * b_float_diff) + (g_float_diff * g_float_diff) + | |
| 101 (r_float_diff * r_float_diff) + (a_float_diff * a_float_diff)); | |
| 102 } | |
| 103 | |
| 104 // Returns true if each channel of the given two colors are "close." This is | |
| 105 // used for comparing colors where rounding errors may cause off-by-one. | |
| 106 bool ColorsClose(uint32_t a, uint32_t b) { | |
| 107 return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 && | |
| 108 abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 && | |
| 109 abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2 && | |
| 110 abs(static_cast<int>(SkColorGetA(a) - SkColorGetA(b))) < 2; | |
| 111 } | |
| 112 | |
| 113 void FillDataToBitmap(int w, int h, SkBitmap* bmp) { | |
| 114 bmp->allocN32Pixels(w, h); | |
| 115 | |
| 116 for (int y = 0; y < h; ++y) { | |
| 117 for (int x = 0; x < w; ++x) { | |
| 118 const uint8_t component = static_cast<uint8_t>(y * w + x); | |
| 119 const SkColor pixel = SkColorSetARGB(component, component, | |
| 120 component, component); | |
| 121 *bmp->getAddr32(x, y) = pixel; | |
| 122 } | |
| 123 } | |
| 124 } | |
| 125 | |
| 126 // Draws a horizontal and vertical grid into the w x h bitmap passed in. | |
| 127 // Each line in the grid is drawn with a width of "grid_width" pixels, | |
| 128 // and those lines repeat every "grid_pitch" pixels. The top left pixel (0, 0) | |
| 129 // is considered to be part of a grid line. | |
| 130 // The pixels that fall on a line are colored with "grid_color", while those | |
| 131 // outside of the lines are colored in "background_color". | |
| 132 // Note that grid_with can be greather than or equal to grid_pitch, in which | |
| 133 // case the resulting bitmap will be a solid color "grid_color". | |
| 134 void DrawGridToBitmap(int w, int h, | |
| 135 SkColor background_color, SkColor grid_color, | |
| 136 int grid_pitch, int grid_width, | |
| 137 SkBitmap* bmp) { | |
| 138 ASSERT_GT(grid_pitch, 0); | |
| 139 ASSERT_GT(grid_width, 0); | |
| 140 ASSERT_NE(background_color, grid_color); | |
| 141 | |
| 142 bmp->allocN32Pixels(w, h); | |
| 143 | |
| 144 for (int y = 0; y < h; ++y) { | |
| 145 bool y_on_grid = ((y % grid_pitch) < grid_width); | |
| 146 | |
| 147 for (int x = 0; x < w; ++x) { | |
| 148 bool on_grid = (y_on_grid || ((x % grid_pitch) < grid_width)); | |
| 149 | |
| 150 *bmp->getAddr32(x, y) = (on_grid ? grid_color : background_color); | |
| 151 } | |
| 152 } | |
| 153 } | |
| 154 | |
| 155 // Draws a checkerboard pattern into the w x h bitmap passed in. | |
| 156 // Each rectangle is rect_w in width, rect_h in height. | |
| 157 // The colors alternate between color1 and color2, color1 being used | |
| 158 // in the rectangle at the top left corner. | |
| 159 void DrawCheckerToBitmap(int w, int h, | |
| 160 SkColor color1, SkColor color2, | |
| 161 int rect_w, int rect_h, | |
| 162 SkBitmap* bmp) { | |
| 163 ASSERT_GT(rect_w, 0); | |
| 164 ASSERT_GT(rect_h, 0); | |
| 165 ASSERT_NE(color1, color2); | |
| 166 | |
| 167 bmp->allocN32Pixels(w, h); | |
| 168 | |
| 169 for (int y = 0; y < h; ++y) { | |
| 170 bool y_bit = (((y / rect_h) & 0x1) == 0); | |
| 171 | |
| 172 for (int x = 0; x < w; ++x) { | |
| 173 bool x_bit = (((x / rect_w) & 0x1) == 0); | |
| 174 | |
| 175 bool use_color2 = (x_bit != y_bit); // xor | |
| 176 | |
| 177 *bmp->getAddr32(x, y) = (use_color2 ? color2 : color1); | |
| 178 } | |
| 179 } | |
| 180 } | |
| 181 | |
| 182 // DEBUG_BITMAP_GENERATION (0 or 1) controls whether the routines | |
| 183 // to save the test bitmaps are present. By default the test just fails | |
| 184 // without reading/writing files but it is then convenient to have | |
| 185 // a simple way to make the failing tests write out the input/output images | |
| 186 // to check them visually. | |
| 187 #define DEBUG_BITMAP_GENERATION (0) | |
| 188 | |
| 189 #if DEBUG_BITMAP_GENERATION | |
| 190 void SaveBitmapToPNG(const SkBitmap& bmp, const char* path) { | |
| 191 SkAutoLockPixels lock(bmp); | |
| 192 std::vector<unsigned char> png; | |
| 193 gfx::PNGCodec::ColorFormat color_format = gfx::PNGCodec::FORMAT_RGBA; | |
| 194 if (!gfx::PNGCodec::Encode( | |
| 195 reinterpret_cast<const unsigned char*>(bmp.getPixels()), | |
| 196 color_format, gfx::Size(bmp.width(), bmp.height()), | |
| 197 static_cast<int>(bmp.rowBytes()), | |
| 198 false, std::vector<gfx::PNGCodec::Comment>(), &png)) { | |
| 199 FAIL() << "Failed to encode image"; | |
| 200 } | |
| 201 | |
| 202 const base::FilePath fpath(path); | |
| 203 const int num_written = | |
| 204 base::WriteFile(fpath, reinterpret_cast<const char*>(&png[0]), | |
| 205 png.size()); | |
| 206 if (num_written != static_cast<int>(png.size())) { | |
| 207 FAIL() << "Failed to write dest \"" << path << '"'; | |
| 208 } | |
| 209 } | |
| 210 #endif // #if DEBUG_BITMAP_GENERATION | |
| 211 | |
| 212 void CheckResampleToSame(skia::ImageOperations::ResizeMethod method) { | |
| 213 // Make our source bitmap. | |
| 214 const int src_w = 16, src_h = 34; | |
| 215 SkBitmap src; | |
| 216 FillDataToBitmap(src_w, src_h, &src); | |
| 217 | |
| 218 // Do a resize of the full bitmap to the same size. The lanczos filter is good | |
| 219 // enough that we should get exactly the same image for output. | |
| 220 SkBitmap results = skia::ImageOperations::Resize(src, method, src_w, src_h); | |
| 221 ASSERT_EQ(src_w, results.width()); | |
| 222 ASSERT_EQ(src_h, results.height()); | |
| 223 | |
| 224 SkAutoLockPixels src_lock(src); | |
| 225 SkAutoLockPixels results_lock(results); | |
| 226 for (int y = 0; y < src_h; y++) { | |
| 227 for (int x = 0; x < src_w; x++) { | |
| 228 EXPECT_EQ(*src.getAddr32(x, y), *results.getAddr32(x, y)); | |
| 229 } | |
| 230 } | |
| 231 } | |
| 232 | |
| 233 // Types defined outside of the ResizeShouldAverageColors test to allow | |
| 234 // use of the arraysize() macro. | |
| 235 // | |
| 236 // 'max_color_distance_override' is used in a max() call together with | |
| 237 // the value of 'max_color_distance' defined in a TestedPixel instance. | |
| 238 // Hence a value of 0.0 in 'max_color_distance_override' means | |
| 239 // "use the pixel-specific value" and larger values can be used to allow | |
| 240 // worse computation errors than provided in a TestedPixel instance. | |
| 241 struct TestedResizeMethod { | |
| 242 skia::ImageOperations::ResizeMethod method; | |
| 243 const char* name; | |
| 244 float max_color_distance_override; | |
| 245 }; | |
| 246 | |
| 247 struct TestedPixel { | |
| 248 int x; | |
| 249 int y; | |
| 250 float max_color_distance; | |
| 251 const char* name; | |
| 252 }; | |
| 253 | |
| 254 // Helper function used by the test "ResizeShouldAverageColors" below. | |
| 255 // Note that ASSERT_EQ does a "return;" on failure, hence we can't have | |
| 256 // a "bool" return value to reflect success. Hence "all_pixels_pass" | |
| 257 void CheckResizeMethodShouldAverageGrid( | |
| 258 const SkBitmap& src, | |
| 259 const TestedResizeMethod& tested_method, | |
| 260 int dest_w, int dest_h, SkColor average_color, | |
| 261 bool* method_passed) { | |
| 262 *method_passed = false; | |
| 263 | |
| 264 const TestedPixel tested_pixels[] = { | |
| 265 // Corners | |
| 266 { 0, 0, 2.3f, "Top left corner" }, | |
| 267 { 0, dest_h - 1, 2.3f, "Bottom left corner" }, | |
| 268 { dest_w - 1, 0, 2.3f, "Top right corner" }, | |
| 269 { dest_w - 1, dest_h - 1, 2.3f, "Bottom right corner" }, | |
| 270 // Middle points of each side | |
| 271 { dest_w / 2, 0, 1.0f, "Top middle" }, | |
| 272 { dest_w / 2, dest_h - 1, 1.0f, "Bottom middle" }, | |
| 273 { 0, dest_h / 2, 1.0f, "Left middle" }, | |
| 274 { dest_w - 1, dest_h / 2, 1.0f, "Right middle" }, | |
| 275 // Center | |
| 276 { dest_w / 2, dest_h / 2, 1.0f, "Center" } | |
| 277 }; | |
| 278 | |
| 279 // Resize the src | |
| 280 const skia::ImageOperations::ResizeMethod method = tested_method.method; | |
| 281 | |
| 282 SkBitmap dest = skia::ImageOperations::Resize(src, method, dest_w, dest_h); | |
| 283 ASSERT_EQ(dest_w, dest.width()); | |
| 284 ASSERT_EQ(dest_h, dest.height()); | |
| 285 | |
| 286 // Check that pixels match the expected average. | |
| 287 float max_observed_distance = 0.0f; | |
| 288 bool all_pixels_ok = true; | |
| 289 | |
| 290 SkAutoLockPixels dest_lock(dest); | |
| 291 | |
| 292 for (size_t pixel_index = 0; | |
| 293 pixel_index < arraysize(tested_pixels); | |
| 294 ++pixel_index) { | |
| 295 const TestedPixel& tested_pixel = tested_pixels[pixel_index]; | |
| 296 | |
| 297 const int x = tested_pixel.x; | |
| 298 const int y = tested_pixel.y; | |
| 299 const float max_allowed_distance = | |
| 300 std::max(tested_pixel.max_color_distance, | |
| 301 tested_method.max_color_distance_override); | |
| 302 | |
| 303 const SkColor actual_color = *dest.getAddr32(x, y); | |
| 304 | |
| 305 // Check that the pixels away from the border region are very close | |
| 306 // to the expected average color | |
| 307 float distance = ColorsEuclidianDistance(average_color, actual_color); | |
| 308 | |
| 309 EXPECT_LE(distance, max_allowed_distance) | |
| 310 << "Resizing method: " << tested_method.name | |
| 311 << ", pixel tested: " << tested_pixel.name | |
| 312 << "(" << x << ", " << y << ")" | |
| 313 << std::hex << std::showbase | |
| 314 << ", expected (avg) hex: " << average_color | |
| 315 << ", actual hex: " << actual_color; | |
| 316 | |
| 317 if (distance > max_allowed_distance) { | |
| 318 all_pixels_ok = false; | |
| 319 } | |
| 320 if (distance > max_observed_distance) { | |
| 321 max_observed_distance = distance; | |
| 322 } | |
| 323 } | |
| 324 | |
| 325 if (!all_pixels_ok) { | |
| 326 ADD_FAILURE() << "Maximum observed color distance for method " | |
| 327 << tested_method.name << ": " << max_observed_distance; | |
| 328 | |
| 329 #if DEBUG_BITMAP_GENERATION | |
| 330 char path[128]; | |
| 331 base::snprintf(path, sizeof(path), | |
| 332 "/tmp/ResizeShouldAverageColors_%s_dest.png", | |
| 333 tested_method.name); | |
| 334 SaveBitmapToPNG(dest, path); | |
| 335 #endif // #if DEBUG_BITMAP_GENERATION | |
| 336 } | |
| 337 | |
| 338 *method_passed = all_pixels_ok; | |
| 339 } | |
| 340 | |
| 341 | |
| 342 } // namespace | |
| 343 | |
| 344 // Helper tests that saves bitmaps to PNGs in /tmp/ to visually check | |
| 345 // that the bitmap generation functions work as expected. | |
| 346 // Those tests are not enabled by default as verification is done | |
| 347 // manually/visually, however it is convenient to leave the functions | |
| 348 // in place. | |
| 349 #if 0 && DEBUG_BITMAP_GENERATION | |
| 350 TEST(ImageOperations, GenerateGradientBitmap) { | |
| 351 // Make our source bitmap. | |
| 352 const int src_w = 640, src_h = 480; | |
| 353 SkBitmap src; | |
| 354 FillDataToBitmap(src_w, src_h, &src); | |
| 355 | |
| 356 SaveBitmapToPNG(src, "/tmp/gradient_640x480.png"); | |
| 357 } | |
| 358 | |
| 359 TEST(ImageOperations, GenerateGridBitmap) { | |
| 360 const int src_w = 640, src_h = 480, src_grid_pitch = 10, src_grid_width = 4; | |
| 361 const SkColor grid_color = SK_ColorRED, background_color = SK_ColorBLUE; | |
| 362 SkBitmap src; | |
| 363 DrawGridToBitmap(src_w, src_h, | |
| 364 background_color, grid_color, | |
| 365 src_grid_pitch, src_grid_width, | |
| 366 &src); | |
| 367 | |
| 368 SaveBitmapToPNG(src, "/tmp/grid_640x408_10_4_red_blue.png"); | |
| 369 } | |
| 370 | |
| 371 TEST(ImageOperations, GenerateCheckerBitmap) { | |
| 372 const int src_w = 640, src_h = 480, rect_w = 10, rect_h = 4; | |
| 373 const SkColor color1 = SK_ColorRED, color2 = SK_ColorBLUE; | |
| 374 SkBitmap src; | |
| 375 DrawCheckerToBitmap(src_w, src_h, color1, color2, rect_w, rect_h, &src); | |
| 376 | |
| 377 SaveBitmapToPNG(src, "/tmp/checker_640x408_10_4_red_blue.png"); | |
| 378 } | |
| 379 #endif // #if ... && DEBUG_BITMAP_GENERATION | |
| 380 | |
| 381 // Makes the bitmap 50% the size as the original using a box filter. This is | |
| 382 // an easy operation that we can check the results for manually. | |
| 383 TEST(ImageOperations, Halve) { | |
| 384 // Make our source bitmap. | |
| 385 int src_w = 30, src_h = 38; | |
| 386 SkBitmap src; | |
| 387 FillDataToBitmap(src_w, src_h, &src); | |
| 388 | |
| 389 // Do a halving of the full bitmap. | |
| 390 SkBitmap actual_results = skia::ImageOperations::Resize( | |
| 391 src, skia::ImageOperations::RESIZE_BOX, src_w / 2, src_h / 2); | |
| 392 ASSERT_EQ(src_w / 2, actual_results.width()); | |
| 393 ASSERT_EQ(src_h / 2, actual_results.height()); | |
| 394 | |
| 395 // Compute the expected values & compare. | |
| 396 SkAutoLockPixels lock(actual_results); | |
| 397 for (int y = 0; y < actual_results.height(); y++) { | |
| 398 for (int x = 0; x < actual_results.width(); x++) { | |
| 399 // Note that those expressions take into account the "half-pixel" | |
| 400 // offset that comes into play due to considering the coordinates | |
| 401 // of the center of the pixels. So x * 2 is a simplification | |
| 402 // of ((x+0.5) * 2 - 1) and (x * 2 + 1) is really (x + 0.5) * 2. | |
| 403 int first_x = x * 2; | |
| 404 int last_x = std::min(src_w - 1, x * 2 + 1); | |
| 405 | |
| 406 int first_y = y * 2; | |
| 407 int last_y = std::min(src_h - 1, y * 2 + 1); | |
| 408 | |
| 409 const uint32_t expected_color = AveragePixel(src, | |
| 410 first_x, last_x, | |
| 411 first_y, last_y); | |
| 412 const uint32_t actual_color = *actual_results.getAddr32(x, y); | |
| 413 const bool close = ColorsClose(expected_color, actual_color); | |
| 414 EXPECT_TRUE(close); | |
| 415 if (!close) { | |
| 416 char str[128]; | |
| 417 base::snprintf(str, sizeof(str), | |
| 418 "exp[%d,%d] = %08X, actual[%d,%d] = %08X", | |
| 419 x, y, expected_color, x, y, actual_color); | |
| 420 ADD_FAILURE() << str; | |
| 421 PrintPixel(src, first_x, last_x, first_y, last_y); | |
| 422 } | |
| 423 } | |
| 424 } | |
| 425 } | |
| 426 | |
| 427 TEST(ImageOperations, HalveSubset) { | |
| 428 // Make our source bitmap. | |
| 429 int src_w = 16, src_h = 34; | |
| 430 SkBitmap src; | |
| 431 FillDataToBitmap(src_w, src_h, &src); | |
| 432 | |
| 433 // Do a halving of the full bitmap. | |
| 434 SkBitmap full_results = skia::ImageOperations::Resize( | |
| 435 src, skia::ImageOperations::RESIZE_BOX, src_w / 2, src_h / 2); | |
| 436 ASSERT_EQ(src_w / 2, full_results.width()); | |
| 437 ASSERT_EQ(src_h / 2, full_results.height()); | |
| 438 | |
| 439 // Now do a halving of a a subset, recall the destination subset is in the | |
| 440 // destination coordinate system (max = half of the original image size). | |
| 441 SkIRect subset_rect = { 2, 3, 3, 6 }; | |
| 442 SkBitmap subset_results = skia::ImageOperations::Resize( | |
| 443 src, skia::ImageOperations::RESIZE_BOX, | |
| 444 src_w / 2, src_h / 2, subset_rect); | |
| 445 ASSERT_EQ(subset_rect.width(), subset_results.width()); | |
| 446 ASSERT_EQ(subset_rect.height(), subset_results.height()); | |
| 447 | |
| 448 // The computed subset and the corresponding subset of the original image | |
| 449 // should be the same. | |
| 450 SkAutoLockPixels full_lock(full_results); | |
| 451 SkAutoLockPixels subset_lock(subset_results); | |
| 452 for (int y = 0; y < subset_rect.height(); y++) { | |
| 453 for (int x = 0; x < subset_rect.width(); x++) { | |
| 454 ASSERT_EQ( | |
| 455 *full_results.getAddr32(x + subset_rect.fLeft, y + subset_rect.fTop), | |
| 456 *subset_results.getAddr32(x, y)); | |
| 457 } | |
| 458 } | |
| 459 } | |
| 460 | |
| 461 TEST(ImageOperations, InvalidParams) { | |
| 462 // Make our source bitmap. | |
| 463 SkBitmap src; | |
| 464 src.allocPixels(SkImageInfo::MakeA8(16, 34)); | |
| 465 | |
| 466 // Scale it, don't die. | |
| 467 SkBitmap full_results = skia::ImageOperations::Resize( | |
| 468 src, skia::ImageOperations::RESIZE_BOX, 10, 20); | |
| 469 } | |
| 470 | |
| 471 // Resamples an image to the same image, it should give the same result. | |
| 472 TEST(ImageOperations, ResampleToSameHamming1) { | |
| 473 CheckResampleToSame(skia::ImageOperations::RESIZE_HAMMING1); | |
| 474 } | |
| 475 | |
| 476 TEST(ImageOperations, ResampleToSameLanczos2) { | |
| 477 CheckResampleToSame(skia::ImageOperations::RESIZE_LANCZOS2); | |
| 478 } | |
| 479 | |
| 480 TEST(ImageOperations, ResampleToSameLanczos3) { | |
| 481 CheckResampleToSame(skia::ImageOperations::RESIZE_LANCZOS3); | |
| 482 } | |
| 483 | |
| 484 // Check that all Good/Better/Best, Box, Lanczos2 and Lanczos3 generate purple | |
| 485 // when resizing a 4x8 red/blue checker pattern by 1/16x1/16. | |
| 486 TEST(ImageOperations, ResizeShouldAverageColors) { | |
| 487 // Make our source bitmap. | |
| 488 const int src_w = 640, src_h = 480, checker_rect_w = 4, checker_rect_h = 8; | |
| 489 const SkColor checker_color1 = SK_ColorRED, checker_color2 = SK_ColorBLUE; | |
| 490 | |
| 491 const int dest_w = src_w / (4 * checker_rect_w); | |
| 492 const int dest_h = src_h / (2 * checker_rect_h); | |
| 493 | |
| 494 // Compute the expected (average) color | |
| 495 const SkColor colors[] = { checker_color1, checker_color2 }; | |
| 496 const SkColor average_color = AveragePixel(colors, arraysize(colors)); | |
| 497 | |
| 498 static const TestedResizeMethod tested_methods[] = { | |
| 499 { skia::ImageOperations::RESIZE_GOOD, "GOOD", 0.0f }, | |
| 500 { skia::ImageOperations::RESIZE_BETTER, "BETTER", 0.0f }, | |
| 501 { skia::ImageOperations::RESIZE_BEST, "BEST", 0.0f }, | |
| 502 { skia::ImageOperations::RESIZE_BOX, "BOX", 0.0f }, | |
| 503 { skia::ImageOperations::RESIZE_HAMMING1, "HAMMING1", 0.0f }, | |
| 504 { skia::ImageOperations::RESIZE_LANCZOS2, "LANCZOS2", 0.0f }, | |
| 505 { skia::ImageOperations::RESIZE_LANCZOS3, "LANCZOS3", 0.0f }, | |
| 506 }; | |
| 507 | |
| 508 // Create our source bitmap. | |
| 509 SkBitmap src; | |
| 510 DrawCheckerToBitmap(src_w, src_h, | |
| 511 checker_color1, checker_color2, | |
| 512 checker_rect_w, checker_rect_h, | |
| 513 &src); | |
| 514 | |
| 515 // For each method, downscale by 16 in each dimension, | |
| 516 // and check each tested pixel against the expected average color. | |
| 517 bool all_methods_ok = true; | |
| 518 | |
| 519 for (size_t method_index = 0; | |
| 520 method_index < arraysize(tested_methods); | |
| 521 ++method_index) { | |
| 522 bool pass = true; | |
| 523 CheckResizeMethodShouldAverageGrid(src, | |
| 524 tested_methods[method_index], | |
| 525 dest_w, dest_h, average_color, | |
| 526 &pass); | |
| 527 if (!pass) { | |
| 528 all_methods_ok = false; | |
| 529 } | |
| 530 } | |
| 531 | |
| 532 if (!all_methods_ok) { | |
| 533 #if DEBUG_BITMAP_GENERATION | |
| 534 SaveBitmapToPNG(src, "/tmp/ResizeShouldAverageColors_src.png"); | |
| 535 #endif // #if DEBUG_BITMAP_GENERATION | |
| 536 } | |
| 537 } | |
| 538 | |
| 539 | |
| 540 // Check that Lanczos2 and Lanczos3 thumbnails produce similar results | |
| 541 TEST(ImageOperations, CompareLanczosMethods) { | |
| 542 const int src_w = 640, src_h = 480, src_grid_pitch = 8, src_grid_width = 4; | |
| 543 | |
| 544 const int dest_w = src_w / 4; | |
| 545 const int dest_h = src_h / 4; | |
| 546 | |
| 547 // 5.0f is the maximum distance we see in this test given the current | |
| 548 // parameters. The value is very ad-hoc and the parameters of the scaling | |
| 549 // were picked to produce a small value. So this test is very much about | |
| 550 // revealing egregious regression rather than doing a good job at checking | |
| 551 // the math behind the filters. | |
| 552 // TODO(evannier): because of the half pixel error mentioned inside | |
| 553 // image_operations.cc, this distance is much larger than it should be. | |
| 554 // This should read: | |
| 555 // const float max_color_distance = 5.0f; | |
| 556 const float max_color_distance = 12.1f; | |
| 557 | |
| 558 // Make our source bitmap. | |
| 559 SkColor grid_color = SK_ColorRED, background_color = SK_ColorBLUE; | |
| 560 SkBitmap src; | |
| 561 DrawGridToBitmap(src_w, src_h, | |
| 562 background_color, grid_color, | |
| 563 src_grid_pitch, src_grid_width, | |
| 564 &src); | |
| 565 | |
| 566 // Resize the src using both methods. | |
| 567 SkBitmap dest_l2 = skia::ImageOperations::Resize( | |
| 568 src, | |
| 569 skia::ImageOperations::RESIZE_LANCZOS2, | |
| 570 dest_w, dest_h); | |
| 571 ASSERT_EQ(dest_w, dest_l2.width()); | |
| 572 ASSERT_EQ(dest_h, dest_l2.height()); | |
| 573 | |
| 574 SkBitmap dest_l3 = skia::ImageOperations::Resize( | |
| 575 src, | |
| 576 skia::ImageOperations::RESIZE_LANCZOS3, | |
| 577 dest_w, dest_h); | |
| 578 ASSERT_EQ(dest_w, dest_l3.width()); | |
| 579 ASSERT_EQ(dest_h, dest_l3.height()); | |
| 580 | |
| 581 // Compare the pixels produced by both methods. | |
| 582 float max_observed_distance = 0.0f; | |
| 583 bool all_pixels_ok = true; | |
| 584 | |
| 585 SkAutoLockPixels l2_lock(dest_l2); | |
| 586 SkAutoLockPixels l3_lock(dest_l3); | |
| 587 for (int y = 0; y < dest_h; ++y) { | |
| 588 for (int x = 0; x < dest_w; ++x) { | |
| 589 const SkColor color_lanczos2 = *dest_l2.getAddr32(x, y); | |
| 590 const SkColor color_lanczos3 = *dest_l3.getAddr32(x, y); | |
| 591 | |
| 592 float distance = ColorsEuclidianDistance(color_lanczos2, color_lanczos3); | |
| 593 | |
| 594 EXPECT_LE(distance, max_color_distance) | |
| 595 << "pixel tested: (" << x << ", " << y | |
| 596 << std::hex << std::showbase | |
| 597 << "), lanczos2 hex: " << color_lanczos2 | |
| 598 << ", lanczos3 hex: " << color_lanczos3 | |
| 599 << std::setprecision(2) | |
| 600 << ", distance: " << distance; | |
| 601 | |
| 602 if (distance > max_color_distance) { | |
| 603 all_pixels_ok = false; | |
| 604 } | |
| 605 if (distance > max_observed_distance) { | |
| 606 max_observed_distance = distance; | |
| 607 } | |
| 608 } | |
| 609 } | |
| 610 | |
| 611 if (!all_pixels_ok) { | |
| 612 ADD_FAILURE() << "Maximum observed color distance: " | |
| 613 << max_observed_distance; | |
| 614 | |
| 615 #if DEBUG_BITMAP_GENERATION | |
| 616 SaveBitmapToPNG(src, "/tmp/CompareLanczosMethods_source.png"); | |
| 617 SaveBitmapToPNG(dest_l2, "/tmp/CompareLanczosMethods_lanczos2.png"); | |
| 618 SaveBitmapToPNG(dest_l3, "/tmp/CompareLanczosMethods_lanczos3.png"); | |
| 619 #endif // #if DEBUG_BITMAP_GENERATION | |
| 620 } | |
| 621 } | |
| 622 | |
| 623 #ifndef M_PI | |
| 624 // No M_PI in math.h on windows? No problem. | |
| 625 #define M_PI 3.14159265358979323846 | |
| 626 #endif | |
| 627 | |
| 628 static double sinc(double x) { | |
| 629 if (x == 0.0) return 1.0; | |
| 630 x *= M_PI; | |
| 631 return sin(x) / x; | |
| 632 } | |
| 633 | |
| 634 static double lanczos3(double offset) { | |
| 635 if (fabs(offset) >= 3) return 0.0; | |
| 636 return sinc(offset) * sinc(offset / 3.0); | |
| 637 } | |
| 638 | |
| 639 TEST(ImageOperations, ScaleUp) { | |
| 640 const int src_w = 3; | |
| 641 const int src_h = 3; | |
| 642 const int dst_w = 9; | |
| 643 const int dst_h = 9; | |
| 644 SkBitmap src; | |
| 645 src.allocN32Pixels(src_w, src_h); | |
| 646 | |
| 647 for (int src_y = 0; src_y < src_h; ++src_y) { | |
| 648 for (int src_x = 0; src_x < src_w; ++src_x) { | |
| 649 *src.getAddr32(src_x, src_y) = SkColorSetARGBInline(255, | |
| 650 10 + src_x * 100, | |
| 651 10 + src_y * 100, | |
| 652 0); | |
| 653 } | |
| 654 } | |
| 655 | |
| 656 SkBitmap dst = skia::ImageOperations::Resize( | |
| 657 src, | |
| 658 skia::ImageOperations::RESIZE_LANCZOS3, | |
| 659 dst_w, dst_h); | |
| 660 SkAutoLockPixels dst_lock(dst); | |
| 661 for (int dst_y = 0; dst_y < dst_h; ++dst_y) { | |
| 662 for (int dst_x = 0; dst_x < dst_w; ++dst_x) { | |
| 663 float dst_x_in_src = (dst_x + 0.5) * src_w / dst_w; | |
| 664 float dst_y_in_src = (dst_y + 0.5) * src_h / dst_h; | |
| 665 float a = 0.0f; | |
| 666 float r = 0.0f; | |
| 667 float g = 0.0f; | |
| 668 float b = 0.0f; | |
| 669 float sum = 0.0f; | |
| 670 for (int src_y = 0; src_y < src_h; ++src_y) { | |
| 671 for (int src_x = 0; src_x < src_w; ++src_x) { | |
| 672 double coeff = | |
| 673 lanczos3(src_x + 0.5 - dst_x_in_src) * | |
| 674 lanczos3(src_y + 0.5 - dst_y_in_src); | |
| 675 sum += coeff; | |
| 676 SkColor tmp = *src.getAddr32(src_x, src_y); | |
| 677 a += coeff * SkColorGetA(tmp); | |
| 678 r += coeff * SkColorGetR(tmp); | |
| 679 g += coeff * SkColorGetG(tmp); | |
| 680 b += coeff * SkColorGetB(tmp); | |
| 681 } | |
| 682 } | |
| 683 a /= sum; | |
| 684 r /= sum; | |
| 685 g /= sum; | |
| 686 b /= sum; | |
| 687 if (a < 0.0f) a = 0.0f; | |
| 688 if (r < 0.0f) r = 0.0f; | |
| 689 if (g < 0.0f) g = 0.0f; | |
| 690 if (b < 0.0f) b = 0.0f; | |
| 691 if (a > 255.0f) a = 255.0f; | |
| 692 if (r > 255.0f) r = 255.0f; | |
| 693 if (g > 255.0f) g = 255.0f; | |
| 694 if (b > 255.0f) b = 255.0f; | |
| 695 SkColor dst_color = *dst.getAddr32(dst_x, dst_y); | |
| 696 EXPECT_LE(fabs(SkColorGetA(dst_color) - a), 1.5f); | |
| 697 EXPECT_LE(fabs(SkColorGetR(dst_color) - r), 1.5f); | |
| 698 EXPECT_LE(fabs(SkColorGetG(dst_color) - g), 1.5f); | |
| 699 EXPECT_LE(fabs(SkColorGetB(dst_color) - b), 1.5f); | |
| 700 if (HasFailure()) { | |
| 701 return; | |
| 702 } | |
| 703 } | |
| 704 } | |
| 705 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1519243002:
Remove many unused files from //skia/ext (Closed)
Base URL: git@github.com:domokit/mojo.git@master