50 lines
1.4 KiB
C

#ifndef OCR_H
#define OCR_H
#include "../scan.h"
#include <tesseract/capi.h>
#define MIN_OCR_WIDTH 350
#define MIN_OCR_HEIGHT 100
#define MIN_OCR_LEN 10
#define OCR_IS_VALID_BPP(d) \
((d) == 1 || (d) == 2 || (d) == 4 || (d) == 8 || (d) == 16 || (d) == 24 || \
(d) == 32)
typedef void (*ocr_extract_callback_t)(const char *, size_t);
__always_inline static void
ocr_extract_text(const char *tesseract_path, const char *tesseract_lang,
const unsigned char *img_buf, const int img_w, const int img_h,
const int img_bpp, const int img_stride, const int img_xres,
const ocr_extract_callback_t cb) {
if (img_w < MIN_OCR_WIDTH || img_h < MIN_OCR_HEIGHT || img_xres <= 0 ||
!OCR_IS_VALID_BPP(img_bpp)) {
return;
}
TessBaseAPI *api = TessBaseAPICreate();
TessBaseAPIInit3(api, tesseract_path, tesseract_lang);
TessBaseAPISetPageSegMode(api, PSM_AUTO_OSD);
TessBaseAPISetImage(api, img_buf, img_w, img_h, img_bpp, img_stride);
TessBaseAPISetSourceResolution(api, img_xres);
char *text = TessBaseAPIGetUTF8Text(api);
if (text != NULL) {
size_t len = strlen(text);
if (len >= MIN_OCR_LEN) {
cb(text, len);
}
TessDeleteText(text);
}
TessBaseAPIEnd(api);
TessBaseAPIDelete(api);
}
#endif