1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.camera;
18
19/**
20 * The Java interface to JNI calls regarding mosaic stitching.
21 *
22 * A high-level usage is:
23 *
24 * Mosaic mosaic = new Mosaic();
25 * mosaic.setSourceImageDimensions(width, height);
26 * mosaic.reset(blendType);
27 *
28 * while ((pixels = hasNextImage()) != null) {
29 *    mosaic.setSourceImage(pixels);
30 * }
31 *
32 * mosaic.createMosaic(highRes);
33 * byte[] result = mosaic.getFinalMosaic();
34 *
35 */
36public class Mosaic {
37    /**
38     * In this mode, the images are stitched together in the same spatial arrangement as acquired
39     * i.e. if the user follows a curvy trajectory, the image boundary of the resulting mosaic will
40     * be curved in the same manner. This mode is useful if the user wants to capture a mosaic as
41     * if "painting" the scene using the smart-phone device and does not want any corrective warps
42     * to distort the captured images.
43     */
44    public static final int BLENDTYPE_FULL = 0;
45
46    /**
47     * This mode is the same as BLENDTYPE_FULL except that the resulting mosaic is rotated
48     * to balance the first and last images to be approximately at the same vertical offset in the
49     * output mosaic. This is useful when acquiring a mosaic by a typical panning-like motion to
50     * remove a one-sided curve in the mosaic (typically due to the camera not staying horizontal
51     * during the video capture) and convert it to a more symmetrical "smiley-face" like output.
52     */
53    public static final int BLENDTYPE_PAN = 1;
54
55    /**
56     * This mode compensates for typical "smiley-face" like output in longer mosaics and creates
57     * a rectangular mosaic with minimal black borders (by unwrapping the mosaic onto an imaginary
58     * cylinder). If the user follows a curved trajectory (instead of a perfect panning trajectory),
59     * the resulting mosaic here may suffer from some image distortions in trying to map the
60     * trajectory to a cylinder.
61     */
62    public static final int BLENDTYPE_CYLINDERPAN = 2;
63
64    /**
65     * This mode is basically BLENDTYPE_CYLINDERPAN plus doing a rectangle cropping before returning
66     * the mosaic. The mode is useful for making the resulting mosaic have a rectangle shape.
67     */
68    public static final int BLENDTYPE_HORIZONTAL =3;
69
70    /**
71     * This strip type will use the default thin strips where the strips are
72     * spaced according to the image capture rate.
73     */
74    public static final int STRIPTYPE_THIN = 0;
75
76    /**
77     * This strip type will use wider strips for blending. The strip separation
78     * is controlled by a threshold on the native side. Since the strips are
79     * wider, there is an additional cross-fade blending step to make the seam
80     * boundaries smoother. Since this mode uses lesser image frames, it is
81     * computationally more efficient than the thin strip mode.
82     */
83    public static final int STRIPTYPE_WIDE = 1;
84
85    /**
86     * Return flags returned by createMosaic() are one of the following.
87     */
88    public static final int MOSAIC_RET_OK = 1;
89    public static final int MOSAIC_RET_ERROR = -1;
90    public static final int MOSAIC_RET_CANCELLED = -2;
91    public static final int MOSAIC_RET_LOW_TEXTURE = -3;
92    public static final int MOSAIC_RET_FEW_INLIERS = 2;
93
94
95    static {
96        System.loadLibrary("jni_mosaic");
97    }
98
99    /**
100     * Allocate memory for the image frames at the given resolution.
101     *
102     * @param width width of the input frames in pixels
103     * @param height height of the input frames in pixels
104     */
105    public native void allocateMosaicMemory(int width, int height);
106
107    /**
108     * Free memory allocated by allocateMosaicMemory.
109     *
110     */
111    public native void freeMosaicMemory();
112
113    /**
114     * Pass the input image frame to the native layer. Each time the a new
115     * source image t is set, the transformation matrix from the first source
116     * image to t is computed and returned.
117     *
118     * @param pixels source image of NV21 format.
119     * @return Float array of length 11; first 9 entries correspond to the 3x3
120     *         transformation matrix between the first frame and the passed frame;
121     *         the 10th entry is the number of the passed frame, where the counting
122     *         starts from 1; and the 11th entry is the returning code, whose value
123     *         is one of those MOSAIC_RET_* returning flags defined above.
124     */
125    public native float[] setSourceImage(byte[] pixels);
126
127    /**
128     * This is an alternative to the setSourceImage function above. This should
129     * be called when the image data is already on the native side in a fixed
130     * byte array. In implementation, this array is filled by the GL thread
131     * using glReadPixels directly from GPU memory (where it is accessed by
132     * an associated SurfaceTexture).
133     *
134     * @return Float array of length 11; first 9 entries correspond to the 3x3
135     *         transformation matrix between the first frame and the passed frame;
136     *         the 10th entry is the number of the passed frame, where the counting
137     *         starts from 1; and the 11th entry is the returning code, whose value
138     *         is one of those MOSAIC_RET_* returning flags defined above.
139     */
140    public native float[] setSourceImageFromGPU();
141
142    /**
143     * Set the type of blending.
144     *
145     * @param type the blending type defined in the class. {BLENDTYPE_FULL,
146     *        BLENDTYPE_PAN, BLENDTYPE_CYLINDERPAN, BLENDTYPE_HORIZONTAL}
147     */
148    public native void setBlendingType(int type);
149
150    /**
151     * Set the type of strips to use for blending.
152     * @param type the blending strip type to use {STRIPTYPE_THIN,
153     * STRIPTYPE_WIDE}.
154     */
155    public native void setStripType(int type);
156
157    /**
158     * Tell the native layer to create the final mosaic after all the input frame
159     * data have been collected.
160     * The case of generating high-resolution mosaic may take dozens of seconds to finish.
161     *
162     * @param value True means generating a high-resolution mosaic -
163     *        which is based on the original images set in setSourceImage().
164     *        False means generating a low-resolution version -
165     *        which is based on 1/4 downscaled images from the original images.
166     * @return Returns a status code suggesting if the mosaic building was
167     *        successful, in error, or was cancelled by the user.
168     */
169    public native int createMosaic(boolean value);
170
171    /**
172     * Get the data for the created mosaic.
173     *
174     * @return Returns an integer array which contains the final mosaic in the ARGB_8888 format.
175     *         The first MosaicWidth*MosaicHeight values contain the image data, followed by 2
176     *         integers corresponding to the values MosaicWidth and MosaicHeight respectively.
177     */
178    public native int[] getFinalMosaic();
179
180    /**
181     * Get the data for the created mosaic.
182     *
183     * @return Returns a byte array which contains the final mosaic in the NV21 format.
184     *         The first MosaicWidth*MosaicHeight*1.5 values contain the image data, followed by
185     *         8 bytes which pack the MosaicWidth and MosaicHeight integers into 4 bytes each
186     *         respectively.
187     */
188    public native byte[] getFinalMosaicNV21();
189
190    /**
191     * Reset the state of the frame arrays which maintain the captured frame data.
192     * Also re-initializes the native mosaic object to make it ready for capturing a new mosaic.
193     */
194    public native void reset();
195
196    /**
197     * Get the progress status of the mosaic computation process.
198     * @param hires Boolean flag to select whether to report progress of the
199     *              low-res or high-res mosaicer.
200     * @param cancelComputation Boolean flag to allow cancelling the
201     *              mosaic computation when needed from the GUI end.
202     * @return Returns a number from 0-100 where 50 denotes that the mosaic
203     *          computation is 50% done.
204     */
205    public native int reportProgress(boolean hires, boolean cancelComputation);
206}
207