[PATCH] Add dilate libopencv filter.
Stefano Sabatini
stefano.sabatini-lala
Sat Oct 2 17:03:38 CEST 2010
---
doc/filters.texi | 44 ++++++++++++
libavfilter/vf_libopencv.c | 165 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 209 insertions(+), 0 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index e217f4e..7f51028 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -532,6 +532,50 @@ informations:
Follows the list of supported libopencv filters.
+ at subsection dilate
+
+Dilate an image by using a specific structuring element.
+Takes the parameters: @var{struct_el}:@var{nb_iterations}.
+
+ at var{struct_el} represents a structuring element, and has the syntax:
+ at var{w}x at var{h}+ at var{anchor_x}x at var{anchor_y}/@var{shape}
+
+ at var{w} and @var{h} represent the width and height of the structuring
+element, @var{anchor_x} and @var{anchor_y} the anchor point, and
+ at var{shape} the shape for the structuring element, and can assume the
+values "rect", "cross", "ellipse", "custom".
+
+If the value for @var{shape} is "custom", it must be followed by a
+string of the form "=@var{filename}". The file corresponding to
+ at var{filename} is assumed to represent a binary image, each printable
+character corresponding to the empty value. Note that in this case
+ at var{w} and @var{h} are ignored, the width and height of the read file
+is assumed instead.
+
+The default value for @var{struct_el} is "3x3+0x0/rect".
+
+ at var{nb_iterations} specifies the number of times the transform is
+applied to the image, and defaults to 1.
+
+Follow some example:
+ at example
+# use the default values
+ocv=dilate
+
+# dilate using a structuring element with a 5x5 cross, iterate two times
+ocv=dilate=5x5+2x2/cross:2
+
+# read the shape from the file diamond.shape, iterate two times
+# the file diamond.shape may contain a pattern of characters like this:
+# *
+# ***
+# *****
+# ***
+# *
+# the w and h specified are ignored (but not the anchor point coordinates)
+ocv=0x0+2x2/custom=diamond.shape:2
+ at end example
+
@subsection smooth
Smooth the input video.
diff --git a/libavfilter/vf_libopencv.c b/libavfilter/vf_libopencv.c
index dce22f7..7409f7d 100644
--- a/libavfilter/vf_libopencv.c
+++ b/libavfilter/vf_libopencv.c
@@ -23,8 +23,12 @@
* libopencv wrapper functions
*/
+/* #define DEBUG */
+
#include <opencv/cv.h>
#include <opencv/cxtypes.h>
+#include "libavutil/avstring.h"
+#include "libavutil/file.h"
#include "avfilter.h"
static void fill_iplimage_from_picref(IplImage *img, const AVFilterBufferRef *picref, enum PixelFormat pixfmt)
@@ -127,6 +131,166 @@ static void smooth_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplIm
cvSmooth(inimg, outimg, smooth->type, smooth->param1, smooth->param2, smooth->param3, smooth->param4);
}
+static int read_shape_from_file(int *cols, int *rows, int **values, const char *filename,
+ void *log_ctx)
+{
+ uint8_t *buf, *p, *pend;
+ size_t size;
+ int ret, i, j, w;
+
+ if ((ret = av_file_map(filename, &buf, &size, 0, log_ctx)) < 0)
+ return ret;
+
+ /* prescan file to get the number of lines and the maximum width */
+ w = 0;
+ for (i = 0; i < size; i++) {
+ if (buf[i] == '\n') {
+ if (*rows == INT_MAX) {
+ av_log(log_ctx, AV_LOG_ERROR, "Overflow on the number of rows in the file\n");
+ return AVERROR_INVALIDDATA;
+ }
+ ++(*rows);
+ *cols = FFMAX(*cols, w);
+ w = 0;
+ } else if (w == INT_MAX) {
+ av_log(log_ctx, AV_LOG_ERROR, "Overflow on the number of columns in the file\n");
+ return AVERROR_INVALIDDATA;
+ }
+ w++;
+ }
+ if (*rows > (FF_INTERNAL_MEM_TYPE_MAX_VALUE / (sizeof(int)) / *cols)) {
+ av_log(log_ctx, AV_LOG_ERROR, "File with size %dx%d is too big\n",
+ *rows, *cols);
+ return AVERROR_INVALIDDATA;
+ }
+ if (!(*values = av_mallocz(sizeof(int) * *rows * *cols)))
+ return AVERROR(ENOMEM);
+
+ /* fill *values */
+ p = buf;
+ pend = buf + size-1;
+ for (i = 0; i < *rows; i++) {
+ for (j = 0;; j++) {
+ if (p > pend || *p == '\n') {
+ p++;
+ break;
+ } else
+ (*values)[*cols*i + j] = !!isgraph(*(p++));
+ }
+ }
+ av_file_unmap(buf, size);
+
+#ifdef DEBUG
+ {
+ char *line;
+ if (!(line = av_malloc(*cols + 1)))
+ return AVERROR(ENOMEM);
+ for (i = 0; i < *rows; i++) {
+ for (j = 0; j < *cols; j++)
+ line[j] = (*values)[i * *cols + j] ? '@' : ' ';
+ line[j] = 0;
+ av_log(log_ctx, AV_LOG_DEBUG, "%3d: %s\n", i, line);
+ }
+ av_free(line);
+ }
+#endif
+
+ return 0;
+}
+
+static int parse_iplconvkernel(IplConvKernel **kernel, char *buf, void *log_ctx)
+{
+ char shape_filename[128], shape_str[32] = "rect";
+ int cols = 0, rows = 0, anchor_x = 0, anchor_y = 0, shape = CV_SHAPE_RECT;
+ int *values = NULL, ret;
+
+ sscanf(buf, "%dx%d+%dx%d/%32[^=]=%127s", &cols, &rows, &anchor_x, &anchor_y, shape_str, shape_filename);
+
+ if (!strcmp(shape_str, "rect" )) shape = CV_SHAPE_RECT;
+ else if (!strcmp(shape_str, "cross" )) shape = CV_SHAPE_CROSS;
+ else if (!strcmp(shape_str, "ellipse")) shape = CV_SHAPE_ELLIPSE;
+ else if (!strcmp(shape_str, "custom" )) {
+ shape = CV_SHAPE_CUSTOM;
+ if ((ret = read_shape_from_file(&cols, &rows, &values, shape_filename, log_ctx)) < 0)
+ return ret;
+ } else {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Shape unspecified or type '%s' unknown\n.", shape_str);
+ return AVERROR(EINVAL);
+ }
+
+ if (rows <= 0 || cols <= 0) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Invalid non-positive values for shape size %dx%d\n", cols, rows);
+ return AVERROR(EINVAL);
+ }
+
+ if (anchor_x < 0 || anchor_y < 0 || anchor_x >= cols || anchor_y >= rows) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Shape anchor %dx%d is not inside the rectangle with size %dx%d.\n",
+ anchor_x, anchor_y, cols, rows);
+ return AVERROR(EINVAL);
+ }
+
+ *kernel = cvCreateStructuringElementEx(cols, rows, anchor_x, anchor_y, shape, values);
+ av_freep(&values);
+ if (!*kernel)
+ return AVERROR(ENOMEM);
+
+ av_log(log_ctx, AV_LOG_INFO, "Structuring element: w:%d h:%d x:%d y:%d shape:%s\n",
+ rows, cols, anchor_x, anchor_y, shape_str);
+ return 0;
+}
+
+typedef struct {
+ int nb_iterations;
+ IplConvKernel *kernel;
+} DilateContext;
+
+static av_cold int dilate_init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ OCVContext *ocv = ctx->priv;
+ DilateContext *dilate = ocv->priv;
+ char default_kernel_str[] = "3x3+0x0/rect";
+ char *kernel_str;
+ const char *buf = args;
+ int ret;
+
+ dilate->nb_iterations = 1;
+
+ if (args)
+ kernel_str = av_get_token(&buf, ":");
+ if ((ret = parse_iplconvkernel(&dilate->kernel,
+ *kernel_str ? kernel_str : default_kernel_str,
+ ctx)) < 0)
+ return ret;
+ av_free(kernel_str);
+
+ sscanf(buf, ":%d", &dilate->nb_iterations);
+ av_log(ctx, AV_LOG_INFO, "iterations_nb:%d\n", dilate->nb_iterations);
+ if (dilate->nb_iterations <= 0) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid non-positive value '%d' for nb_iterations\n",
+ dilate->nb_iterations);
+ return AVERROR(EINVAL);
+ }
+ return 0;
+}
+
+static av_cold void dilate_uninit(AVFilterContext *ctx)
+{
+ OCVContext *ocv = ctx->priv;
+ DilateContext *dilate = ocv->priv;
+
+ cvReleaseStructuringElement(&dilate->kernel);
+}
+
+static void dilate_end_frame_filter(AVFilterContext *ctx, IplImage *inimg, IplImage *outimg)
+{
+ OCVContext *ocv = ctx->priv;
+ DilateContext *dilate = ocv->priv;
+ cvDilate(inimg, outimg, dilate->kernel, dilate->nb_iterations);
+}
+
typedef struct {
const char *name;
size_t priv_size;
@@ -136,6 +300,7 @@ typedef struct {
} OCVFilterEntry;
static OCVFilterEntry ocv_filter_entries[] = {
+ { "dilate", sizeof(DilateContext), dilate_init, dilate_uninit, dilate_end_frame_filter },
{ "smooth", sizeof(SmoothContext), smooth_init, NULL, smooth_end_frame_filter },
};
--
1.7.2.3
--wac7ysb48OaltWcw--
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