jint Java_com_googlecode_leptonica_android_ReadFile_nativeReadBytes8(JNIEnv *env, jclass clazz,
jbyteArray data, jint w,
jint h) {
LOGV(__FUNCTION__);
PIX *pix = pixCreateNoInit((l_int32) w, (l_int32) h, 8);
l_uint8 **lineptrs = pixSetupByteProcessing(pix, NULL, NULL);
jbyte *data_buffer = env->GetByteArrayElements(data, NULL);
l_uint8 *byte_buffer = (l_uint8 *) data_buffer;
for (int i = 0; i < h; i++) {
memcpy(lineptrs[i], (byte_buffer + (i * w)), w);
}
env->ReleaseByteArrayElements(data, data_buffer, JNI_ABORT);
pixCleanupByteProcessing(pix, lineptrs);
l_int32 d;
pixGetDimensions(pix, &w, &h, &d);
LOGE("Created image width w=%d, h=%d, d=%d", w, h, d);
return (jint) pix;
}
/*!
* pixCreate()
*
* Input: width, height, depth
* Return: pixd (with data allocated and initialized to 0),
* or null on error
*/
PIX *
pixCreate(l_int32 width,
l_int32 height,
l_int32 depth)
{
PIX *pixd;
PROCNAME("pixCreate");
if ((pixd = pixCreateNoInit(width, height, depth)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
memset(pixd->data, 0, 4 * pixd->wpl * pixd->h);
return pixd;
}
/*!
* pixCreateTemplateNoInit()
*
* Input: pixs
* Return: pixd, or null on error
*
* Notes:
* (1) Makes a Pix of the same size as the input Pix, with
* the data array allocated but not initialized to 0.
* (2) Copies the other fields, including colormap if it exists.
*/
PIX *
pixCreateTemplateNoInit(PIX *pixs)
{
l_int32 w, h, d;
PIX *pixd;
PROCNAME("pixCreateTemplateNoInit");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
pixGetDimensions(pixs, &w, &h, &d);
if ((pixd = pixCreateNoInit(w, h, d)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
pixCopyResolution(pixd, pixs);
pixCopyColormap(pixd, pixs);
pixCopyText(pixd, pixs);
pixCopyInputFormat(pixd, pixs);
return pixd;
}
/*!
* pixSauvolaBinarizeTiled()
*
* Input: pixs (8 bpp grayscale, not colormapped)
* whsize (window half-width for measuring local statistics)
* factor (factor for reducing threshold due to variance; >= 0)
* nx, ny (subdivision into tiles; >= 1)
* &pixth (<optional return> Sauvola threshold values)
* &pixd (<optional return> thresholded image)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) The window width and height are 2 * @whsize + 1. The minimum
* value for @whsize is 2; typically it is >= 7..
* (2) For nx == ny == 1, this defaults to pixSauvolaBinarize().
* (3) Why a tiled version?
* (a) Because the mean value accumulator is a uint32, overflow
* can occur for an image with more than 16M pixels.
* (b) The mean value accumulator array for 16M pixels is 64 MB.
* The mean square accumulator array for 16M pixels is 128 MB.
* Using tiles reduces the size of these arrays.
* (c) Each tile can be processed independently, in parallel,
* on a multicore processor.
* (4) The Sauvola threshold is determined from the formula:
* t = m * (1 - k * (1 - s / 128))
* See pixSauvolaBinarize() for details.
*/
l_int32
pixSauvolaBinarizeTiled(PIX *pixs,
l_int32 whsize,
l_float32 factor,
l_int32 nx,
l_int32 ny,
PIX **ppixth,
PIX **ppixd)
{
l_int32 i, j, w, h, xrat, yrat;
PIX *pixth, *pixd, *tileth, *tiled, *pixt;
PIX **ptileth, **ptiled;
PIXTILING *pt;
PROCNAME("pixSauvolaBinarizeTiled");
if (!ppixth && !ppixd)
return ERROR_INT("no outputs", procName, 1);
if (ppixth) *ppixth = NULL;
if (ppixd) *ppixd = NULL;
if (!pixs || pixGetDepth(pixs) != 8)
return ERROR_INT("pixs undefined or not 8 bpp", procName, 1);
if (pixGetColormap(pixs))
return ERROR_INT("pixs is cmapped", procName, 1);
pixGetDimensions(pixs, &w, &h, NULL);
if (whsize < 2)
return ERROR_INT("whsize must be >= 2", procName, 1);
if (w < 2 * whsize + 3 || h < 2 * whsize + 3)
return ERROR_INT("whsize too large for image", procName, 1);
if (factor < 0.0)
return ERROR_INT("factor must be >= 0", procName, 1);
if (nx <= 1 && ny <= 1)
return pixSauvolaBinarize(pixs, whsize, factor, 1, NULL, NULL,
ppixth, ppixd);
/* Test to see if the tiles are too small. The required
* condition is that the tile dimensions must be at least
* (whsize + 2) x (whsize + 2). */
xrat = w / nx;
yrat = h / ny;
if (xrat < whsize + 2) {
nx = w / (whsize + 2);
L_WARNING("tile width too small; nx reduced to %d\n", procName, nx);
}
if (yrat < whsize + 2) {
ny = h / (whsize + 2);
L_WARNING("tile height too small; ny reduced to %d\n", procName, ny);
}
if (nx <= 1 && ny <= 1)
return pixSauvolaBinarize(pixs, whsize, factor, 1, NULL, NULL,
ppixth, ppixd);
/* We can use pixtiling for painting both outputs, if requested */
if (ppixth) {
pixth = pixCreateNoInit(w, h, 8);
*ppixth = pixth;
}
if (ppixd) {
pixd = pixCreateNoInit(w, h, 1);
*ppixd = pixd;
}
pt = pixTilingCreate(pixs, nx, ny, 0, 0, whsize + 1, whsize + 1);
pixTilingNoStripOnPaint(pt); /* pixSauvolaBinarize() does the stripping */
for (i = 0; i < ny; i++) {
for (j = 0; j < nx; j++) {
pixt = pixTilingGetTile(pt, i, j);
ptileth = (ppixth) ? &tileth : NULL;
ptiled = (ppixd) ? &tiled : NULL;
pixSauvolaBinarize(pixt, whsize, factor, 0, NULL, NULL,
ptileth, ptiled);
if (ppixth) { /* do not strip */
pixTilingPaintTile(pixth, i, j, tileth, pt);
pixDestroy(&tileth);
}
if (ppixd) {
pixTilingPaintTile(pixd, i, j, tiled, pt);
pixDestroy(&tiled);
}
pixDestroy(&pixt);
}
}
pixTilingDestroy(&pt);
return 0;
}
