-
Notifications
You must be signed in to change notification settings - Fork 0
/
flood_fill_png.c
227 lines (157 loc) · 6.97 KB
/
flood_fill_png.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#define PNG_DEBUG 3
#include <png.h>
void abort_(const char * s, ...)
{
va_list args;
va_start(args, s);
vfprintf(stderr, s, args);
fprintf(stderr, "\n");
va_end(args);
abort();
}
int x, y;
int width, height;
png_byte color_type;
png_byte bit_depth;
png_structp png_ptr;
png_infop info_ptr;
int number_of_passes;
png_bytep * row_pointers;
void read_png_file(char* file_name)
{
char header[8]; // 8 is the maximum size that can be checked
/* open file and test for it being a png */
FILE *fp = fopen(file_name, "rb");
if (!fp)
abort_("[read_png_file] File %s could not be opened for reading", file_name);
fread(header, 1, 8, fp);
if (png_sig_cmp(header, 0, 8))
abort_("[read_png_file] File %s is not recognized as a PNG file", file_name);
/* initialize stuff */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
abort_("[read_png_file] png_create_read_struct failed");
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
abort_("[read_png_file] png_create_info_struct failed");
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during init_io");
png_init_io(png_ptr, fp);
png_set_sig_bytes(png_ptr, 8);
png_read_info(png_ptr, info_ptr);
width = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr, info_ptr);
bit_depth = png_get_bit_depth(png_ptr, info_ptr);
number_of_passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
/* read file */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during read_image");
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (y=0; y<height; y++)
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
png_read_image(png_ptr, row_pointers);
fclose(fp);
}
void write_png_file(char* file_name)
{
/* create file */
FILE *fp = fopen(file_name, "wb");
if (!fp)
abort_("[write_png_file] File %s could not be opened for writing", file_name);
/* initialize stuff */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
abort_("[write_png_file] png_create_write_struct failed");
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
abort_("[write_png_file] png_create_info_struct failed");
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during init_io");
png_init_io(png_ptr, fp);
/* write header */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing header");
png_set_IHDR(png_ptr, info_ptr, width, height,
bit_depth, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
png_write_info(png_ptr, info_ptr);
/* write bytes */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing bytes");
png_write_image(png_ptr, row_pointers);
/* end write */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during end of write");
png_write_end(png_ptr, NULL);
/* cleanup heap allocation */
for (y=0; y<height; y++)
free(row_pointers[y]);
free(row_pointers);
fclose(fp);
}
void flood_fill(int node_x, int node_y, int R_val, int G_val, int B_val, int A_val, int R_target, int G_target, int B_target, int A_target) {
// lets make sure we don't step out of bounds
if (node_y >= height || node_y < 0) return;
if (node_x >= width || node_x < 0) return;
png_byte* node_row = row_pointers[node_y];
png_byte* node_ptr = &(node_row[node_x*4]);
// 1. If replacement color is equal to current pixel color, return.
if (((node_ptr[0] == R_target) && (node_ptr[1] == G_target)) && ((node_ptr[2] == B_target) && (node_ptr[3] == A_target))){
return;
// 2. ElseIf the color of the pixel(node) is not equal to target-color, return.
} else if(((node_ptr[0] != R_val) || (node_ptr[1] != G_val)) || ((node_ptr[2] != B_val) || (node_ptr[3] != A_val))){
return;
// 3. Else Set the color of node to replacement-color.
} else {
node_ptr[0] = R_target;
node_ptr[1] = G_target;
node_ptr[2] = B_target;
node_ptr[3] = A_target;
}
/*
4. Perform Flood-fill (one step to the south of node, target-color, replacement-color).
Perform Flood-fill (one step to the north of node, target-color, replacement-color).
Perform Flood-fill (one step to the west of node, target-color, replacement-color).
Perform Flood-fill (one step to the east of node, target-color, replacement-color).
*/
flood_fill(node_x,node_y-1,R_val,G_val,B_val,A_val,R_target,G_target,B_target,A_target); //South
flood_fill(node_x,node_y+1,R_val,G_val,B_val,A_val,R_target,G_target,B_target,A_target); //North
flood_fill(node_x-1,node_y,R_val,G_val,B_val,A_val,R_target,G_target,B_target,A_target); //West
flood_fill(node_x+1,node_y,R_val,G_val,B_val,A_val,R_target,G_target,B_target,A_target); //East
return;
}
void process_file(int x_root, int y_root, int R_val, int G_val, int B_val, int A_val, int R_target, int G_target, int B_target, int A_target)
{
if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGB)
abort_("[process_file] input file is PNG_COLOR_TYPE_RGB but must be PNG_COLOR_TYPE_RGBA "
"(lacks the alpha channel)");
if (png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_RGBA)
abort_("[process_file] color_type of input file must be PNG_COLOR_TYPE_RGBA (%d) (is %d)",
PNG_COLOR_TYPE_RGBA, png_get_color_type(png_ptr, info_ptr));
puts("Starting fill");
//start iterating from the root node
flood_fill(x_root,y_root,R_val,G_val,B_val,A_val,R_target,G_target,B_target,A_target);
puts("Done with fill");
}
int main(int argc, char **argv)
{
if (argc != 13) {
printf("%s", "Usage: flood_fill_png <png_in> <x_root> <y_root> <R> <G> <B> <A> <R_target> <G_target> <B_target> <A_target> <png_out>"
"\nReplaces color in an image using a flood fill algo from a root node\n"
);
exit(1);
}
read_png_file(argv[1]);
process_file(atoi(argv[2]),atoi(argv[3]),atoi(argv[4]),atoi(argv[5]),atoi(argv[6]),atoi(argv[7]),atoi(argv[8]),atoi(argv[9]),atoi(argv[10]),atoi(argv[11]));
puts("Writing png..");
write_png_file(argv[12]);
puts("Done");
return 0;
}