ho_bitmap *
ho_bitmap_filter_hlink (ho_bitmap * m, int size, int max_height)
{
ho_bitmap *m_out;
ho_bitmap *m_temp;
/* this function use objects by the "_by_size" function this is why it is a
* filter and not regular bitmap function */
/* get only the thin objects */
m_temp = ho_bitmap_filter_by_size (m, 5, max_height, 5, m->width / 2);
/* hlink the thin objects */
m_out = ho_bitmap_hlink (m_temp, size);
/* add the rest of the large objects */
ho_bitmap_or (m_out, m);
ho_bitmap_free (m_temp);
return m_out;
}
/**
convert a gray pixbuf to bitmap
@param pix_in the input ho_pixbuf
@param options image process options
@param progress a progress indicator 0..100
@return newly allocated gray ho_bitmap
*/
ho_bitmap *hocr_image_processing (const ho_pixbuf * pix_in, HEBOCR_IMAGE_OPTIONS *image_options, int *progress)
{
ho_bitmap *bitmap_out = NULL;
ho_bitmap *bitmap_temp = NULL;
double angle = 0.0;
int scale_by = 0;
unsigned char size = 0;
/* init progress */
*progress = 0;
/* get the raw b/w bitmap from the pixbuf */
bitmap_temp = ho_pixbuf_to_bitmap_wrapper(pix_in, image_options, size);
if (!bitmap_temp)
return NULL;
/* update progress */
*progress = 25;
/* do we want to auto scale ? */
if (!image_options->scale && image_options->auto_scale)
{
/* get fonts size for autoscale */
if (ho_dimentions_font_width_height_nikud (bitmap_temp, 6, 200, 6, 200))
return NULL;
/* if fonts are too small, re-scale image */
if (bitmap_temp->font_height < 15)
scale_by = 3;
else if (bitmap_temp->font_height < 30)
scale_by = 2;
else
scale_by = 1;
if (scale_by > 1)
{
/* re-create bitmap */
ho_bitmap_free (bitmap_temp);
bitmap_temp = ho_pixbuf_to_bitmap_wrapper (pix_in, image_options, size);
if (!bitmap_temp)
return NULL;
}
}
/* update progress */
*progress = 50;
/* remove very small and very large things */
bitmap_out =
ho_bitmap_filter_by_size (bitmap_temp, 3, 3 * bitmap_temp->height / 4, 3,
3 * bitmap_temp->width / 4);
ho_bitmap_free (bitmap_temp);
if (!bitmap_out)
return NULL;
/* update progress */
*progress = 75;
/* rotate image */
if (image_options->rotation_angle != 0)
{
bitmap_temp = ho_bitmap_rotate(bitmap_out, image_options->rotation_angle);
ho_bitmap_free (bitmap_out);
if (!bitmap_temp)
return NULL;
bitmap_out = bitmap_temp;
}
else if (image_options->auto_rotate)
{
/* get fonts size for auto angle */
if (ho_dimentions_font_width_height_nikud (bitmap_out, 6, 200, 6, 200))
return NULL;
angle = ho_dimentions_get_lines_angle (bitmap_out);
if (angle)
{
bitmap_temp = ho_bitmap_rotate (bitmap_out, angle);
ho_bitmap_free (bitmap_out);
if (!bitmap_temp)
return NULL;
bitmap_out = bitmap_temp;
}
}
return bitmap_out;
}
