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1 // Copyright (c) 2006-2008 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 <stdlib.h> | |
6 | |
7 #include "base/gfx/image_operations.h" | |
8 #include "testing/gtest/include/gtest/gtest.h" | |
9 #include "SkBitmap.h" | |
10 | |
11 namespace { | |
12 | |
13 // Computes the average pixel value for the given range, inclusive. | |
14 uint32_t AveragePixel(const SkBitmap& bmp, | |
15 int x_min, int x_max, | |
16 int y_min, int y_max) { | |
17 float accum[4] = {0, 0, 0, 0}; | |
18 int count = 0; | |
19 for (int y = y_min; y <= y_max; y++) { | |
20 for (int x = x_min; x <= x_max; x++) { | |
21 uint32_t cur = *bmp.getAddr32(x, y); | |
22 accum[0] += SkColorGetB(cur); | |
23 accum[1] += SkColorGetG(cur); | |
24 accum[2] += SkColorGetR(cur); | |
25 accum[3] += SkColorGetA(cur); | |
26 count++; | |
27 } | |
28 } | |
29 | |
30 return SkColorSetARGB(static_cast<unsigned char>(accum[3] / count), | |
31 static_cast<unsigned char>(accum[2] / count), | |
32 static_cast<unsigned char>(accum[1] / count), | |
33 static_cast<unsigned char>(accum[0] / count)); | |
34 } | |
35 | |
36 // Returns true if each channel of the given two colors are "close." This is | |
37 // used for comparing colors where rounding errors may cause off-by-one. | |
38 bool ColorsClose(uint32_t a, uint32_t b) { | |
39 return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 && | |
40 abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 && | |
41 abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2 && | |
42 abs(static_cast<int>(SkColorGetA(a) - SkColorGetA(b))) < 2; | |
43 } | |
44 | |
45 void FillDataToBitmap(int w, int h, SkBitmap* bmp) { | |
46 bmp->setConfig(SkBitmap::kARGB_8888_Config, w, h); | |
47 bmp->allocPixels(); | |
48 | |
49 unsigned char* src_data = | |
50 reinterpret_cast<unsigned char*>(bmp->getAddr32(0, 0)); | |
51 for (int i = 0; i < w * h; i++) { | |
52 src_data[i * 4 + 0] = static_cast<unsigned char>(i % 255); | |
53 src_data[i * 4 + 1] = static_cast<unsigned char>(i % 255); | |
54 src_data[i * 4 + 2] = static_cast<unsigned char>(i % 255); | |
55 src_data[i * 4 + 3] = static_cast<unsigned char>(i % 255); | |
56 } | |
57 } | |
58 | |
59 } // namespace | |
60 | |
61 // Makes the bitmap 50% the size as the original using a box filter. This is | |
62 // an easy operation that we can check the results for manually. | |
63 TEST(ImageOperations, Halve) { | |
64 // Make our source bitmap. | |
65 int src_w = 30, src_h = 38; | |
66 SkBitmap src; | |
67 FillDataToBitmap(src_w, src_h, &src); | |
68 | |
69 // Do a halving of the full bitmap. | |
70 SkBitmap actual_results = gfx::ImageOperations::Resize( | |
71 src, gfx::ImageOperations::RESIZE_BOX, gfx::Size(src_w / 2, src_h / 2)); | |
72 ASSERT_EQ(src_w / 2, actual_results.width()); | |
73 ASSERT_EQ(src_h / 2, actual_results.height()); | |
74 | |
75 // Compute the expected values & compare. | |
76 SkAutoLockPixels lock(actual_results); | |
77 for (int y = 0; y < actual_results.height(); y++) { | |
78 for (int x = 0; x < actual_results.width(); x++) { | |
79 int first_x = std::max(0, x * 2 - 1); | |
80 int last_x = std::min(src_w - 1, x * 2); | |
81 | |
82 int first_y = std::max(0, y * 2 - 1); | |
83 int last_y = std::min(src_h - 1, y * 2); | |
84 | |
85 uint32_t expected_color = AveragePixel(src, | |
86 first_x, last_x, first_y, last_y); | |
87 EXPECT_TRUE(ColorsClose(expected_color, *actual_results.getAddr32(x, y))); | |
88 } | |
89 } | |
90 } | |
91 | |
92 TEST(ImageOperations, HalveSubset) { | |
93 // Make our source bitmap. | |
94 int src_w = 16, src_h = 34; | |
95 SkBitmap src; | |
96 FillDataToBitmap(src_w, src_h, &src); | |
97 | |
98 // Do a halving of the full bitmap. | |
99 SkBitmap full_results = gfx::ImageOperations::Resize( | |
100 src, gfx::ImageOperations::RESIZE_BOX, gfx::Size(src_w / 2, src_h / 2)); | |
101 ASSERT_EQ(src_w / 2, full_results.width()); | |
102 ASSERT_EQ(src_h / 2, full_results.height()); | |
103 | |
104 // Now do a halving of a a subset, recall the destination subset is in the | |
105 // destination coordinate system (max = half of the original image size). | |
106 gfx::Rect subset_rect(2, 3, 3, 6); | |
107 SkBitmap subset_results = gfx::ImageOperations::Resize( | |
108 src, gfx::ImageOperations::RESIZE_BOX, | |
109 gfx::Size(src_w / 2, src_h / 2), subset_rect); | |
110 ASSERT_EQ(subset_rect.width(), subset_results.width()); | |
111 ASSERT_EQ(subset_rect.height(), subset_results.height()); | |
112 | |
113 // The computed subset and the corresponding subset of the original image | |
114 // should be the same. | |
115 SkAutoLockPixels full_lock(full_results); | |
116 SkAutoLockPixels subset_lock(subset_results); | |
117 for (int y = 0; y < subset_rect.height(); y++) { | |
118 for (int x = 0; x < subset_rect.width(); x++) { | |
119 ASSERT_EQ( | |
120 *full_results.getAddr32(x + subset_rect.x(), y + subset_rect.y()), | |
121 *subset_results.getAddr32(x, y)); | |
122 } | |
123 } | |
124 } | |
125 | |
126 // Resamples an iamge to the same image, it should give almost the same result. | |
127 TEST(ImageOperations, ResampleToSame) { | |
128 // Make our source bitmap. | |
129 int src_w = 16, src_h = 34; | |
130 SkBitmap src; | |
131 FillDataToBitmap(src_w, src_h, &src); | |
132 | |
133 // Do a resize of the full bitmap to the same size. The lanczos filter is good | |
134 // enough that we should get exactly the same image for output. | |
135 SkBitmap results = gfx::ImageOperations::Resize( | |
136 src, gfx::ImageOperations::RESIZE_LANCZOS3, gfx::Size(src_w, src_h)); | |
137 ASSERT_EQ(src_w, results.width()); | |
138 ASSERT_EQ(src_h, results.height()); | |
139 | |
140 SkAutoLockPixels src_lock(src); | |
141 SkAutoLockPixels results_lock(results); | |
142 for (int y = 0; y < src_h; y++) { | |
143 for (int x = 0; x < src_w; x++) { | |
144 EXPECT_EQ(*src.getAddr32(x, y), *results.getAddr32(x, y)); | |
145 } | |
146 } | |
147 } | |
148 | |
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