QImage MainWindow::PixToQImage(PIX *pixs) {
// TODO: first check if pixs is PIX ;-) inputFormat(pix)
// create color tables
QVector<QRgb> _bwCT;
_bwCT.append(qRgb(255,255,255));
_bwCT.append(qRgb(0,0,0));
QVector<QRgb> _grayscaleCT(256);
for (int i = 0; i < 256; i++) {
_grayscaleCT.append(qRgb(i, i, i));
}
l_uint32 * s_data = pixGetData(pixEndianByteSwapNew(pixs));
int width = pixGetWidth(pixs);
int height = pixGetHeight(pixs);
int depth = pixGetDepth(pixs);
int bytesPerLine = pixGetWpl(pixs) * 4;
QImage::Format format;
if (depth == 1)
format = QImage::Format_Mono;
else if (depth == 8)
format = QImage::Format_Indexed8;
else
format = QImage::Format_RGB32;
QImage result((uchar*)s_data, width, height, bytesPerLine, format);
if (depth == 1) {
result.setColorTable(_bwCT);
} else if (depth == 8) {
result.setColorTable(_grayscaleCT);
} else {
result.setColorTable(_grayscaleCT);
}
if (result.isNull()) {
static QImage none(0,0,QImage::Format_Invalid);
qDebug() << "***Invalid format!!!";
return none;
}
// QRgb *line = (QRgb*)(result.scanLine(0));
// QColor color = QColor::fromRgb(result.pixel(0,0));
return result.rgbSwapped();
}
/*!
* pixWriteStreamPng()
*
* Input: stream
* pix
* gamma (use 0.0 if gamma is not defined)
* Return: 0 if OK; 1 on error
*
* Notes:
* (1) If called from pixWriteStream(), the stream is positioned
* at the beginning of the file.
* (2) To do sequential writes of png format images to a stream,
* use pixWriteStreamPng() directly.
* (3) gamma is an optional png chunk. If no gamma value is to be
* placed into the file, use gamma = 0.0. Otherwise, if
* gamma > 0.0, its value is written into the header.
* (4) The use of gamma in png is highly problematic. For an illuminating
* discussion, see: http://hsivonen.iki.fi/png-gamma/
* (5) What is the effect/meaning of gamma in the png file? This
* gamma, which we can call the 'source' gamma, is the
* inverse of the gamma that was used in enhance.c to brighten
* or darken images. The 'source' gamma is supposed to indicate
* the intensity mapping that was done at the time the
* image was captured. Display programs typically apply a
* 'display' gamma of 2.2 to the output, which is intended
* to linearize the intensity based on the response of
* thermionic tubes (CRTs). Flat panel LCDs have typically
* been designed to give a similar response as CRTs (call it
* "backward compatibility"). The 'display' gamma is
* in some sense the inverse of the 'source' gamma.
* jpeg encoders attached to scanners and cameras will lighten
* the pixels, applying a gamma corresponding to approximately
* a square-root relation of output vs input:
* output = input^(gamma)
* where gamma is often set near 0.4545 (1/gamma is 2.2).
* This is stored in the image file. Then if the display
* program reads the gamma, it will apply a display gamma,
* typically about 2.2; the product is 1.0, and the
* display program produces a linear output. This works because
* the dark colors were appropriately boosted by the scanner,
* as described by the 'source' gamma, so they should not
* be further boosted by the display program.
* (6) As an example, with xv and display, if no gamma is stored,
* the program acts as if gamma were 0.4545, multiplies this by 2.2,
* and does a linear rendering. Taking this as a baseline
* brightness, if the stored gamma is:
* > 0.4545, the image is rendered lighter than baseline
* < 0.4545, the image is rendered darker than baseline
* In contrast, gqview seems to ignore the gamma chunk in png.
* (7) The only valid pixel depths in leptonica are 1, 2, 4, 8, 16
* and 32. However, it is possible, and in some cases desirable,
* to write out a png file using an rgb pix that has 24 bpp.
* For example, the open source xpdf SplashBitmap class generates
* 24 bpp rgb images. Consequently, we anble writing 24 bpp pix.
* To generate such a pix, you can make a 24 bpp pix without data
* and assign the data array to the pix; e.g.,
* pix = pixCreateHeader(w, h, 24);
* pixSetData(pix, rgbdata);
* See pixConvert32To24() for an example, where we get rgbdata
* from the 32 bpp pix. Caution: do not call pixSetPadBits(),
* because the alignment is wrong and you may erase part of the
* last pixel on each line.
*/
l_int32
pixWriteStreamPng(FILE *fp,
PIX *pix,
l_float32 gamma)
{
char commentstring[] = "Comment";
l_int32 i, j, k;
l_int32 wpl, d, cmflag;
l_int32 ncolors;
l_int32 *rmap, *gmap, *bmap;
l_uint32 *data, *ppixel;
png_byte bit_depth, color_type;
png_uint_32 w, h;
png_uint_32 xres, yres;
png_bytep *row_pointers;
png_bytep rowbuffer;
png_structp png_ptr;
png_infop info_ptr;
png_colorp palette;
PIX *pixt;
PIXCMAP *cmap;
char *text;
PROCNAME("pixWriteStreamPng");
if (!fp)
return ERROR_INT("stream not open", procName, 1);
if (!pix)
return ERROR_INT("pix not defined", procName, 1);
/* Allocate the 2 data structures */
if ((png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
(png_voidp)NULL, NULL, NULL)) == NULL)
return ERROR_INT("png_ptr not made", procName, 1);
if ((info_ptr = png_create_info_struct(png_ptr)) == NULL) {
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
return ERROR_INT("info_ptr not made", procName, 1);
}
/* Set up png setjmp error handling */
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_write_struct(&png_ptr, &info_ptr);
return ERROR_INT("internal png error", procName, 1);
}
png_init_io(png_ptr, fp);
/* With best zlib compression (9), get between 1 and 10% improvement
* over default (5), but the compression is 3 to 10 times slower.
* Our default compression is the zlib default (5). */
png_set_compression_level(png_ptr, var_ZLIB_COMPRESSION);
w = pixGetWidth(pix);
h = pixGetHeight(pix);
d = pixGetDepth(pix);
if ((cmap = pixGetColormap(pix)))
cmflag = 1;
else
cmflag = 0;
/* Set the color type and bit depth. */
if (d == 32 && var_PNG_WRITE_ALPHA == 1) {
bit_depth = 8;
color_type = PNG_COLOR_TYPE_RGBA; /* 6 */
cmflag = 0; /* ignore if it exists */
}
else if (d == 24 || d == 32) {
bit_depth = 8;
color_type = PNG_COLOR_TYPE_RGB; /* 2 */
cmflag = 0; /* ignore if it exists */
}
else {
bit_depth = d;
color_type = PNG_COLOR_TYPE_GRAY; /* 0 */
}
if (cmflag)
color_type = PNG_COLOR_TYPE_PALETTE; /* 3 */
#if DEBUG
fprintf(stderr, "cmflag = %d, bit_depth = %d, color_type = %d\n",
cmflag, bit_depth, color_type);
#endif /* DEBUG */
png_set_IHDR(png_ptr, info_ptr, w, h, bit_depth, color_type,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
/* Store resolution in ppm, if known */
xres = (png_uint_32)(39.37 * (l_float32)pixGetXRes(pix) + 0.5);
yres = (png_uint_32)(39.37 * (l_float32)pixGetYRes(pix) + 0.5);
if ((xres == 0) || (yres == 0))
png_set_pHYs(png_ptr, info_ptr, 0, 0, PNG_RESOLUTION_UNKNOWN);
else
png_set_pHYs(png_ptr, info_ptr, xres, yres, PNG_RESOLUTION_METER);
if (cmflag) {
pixcmapToArrays(cmap, &rmap, &gmap, &bmap);
ncolors = pixcmapGetCount(cmap);
/* Make and save the palette */
if ((palette = (png_colorp)(CALLOC(ncolors, sizeof(png_color))))
== NULL)
return ERROR_INT("palette not made", procName, 1);
for (i = 0; i < ncolors; i++) {
palette[i].red = (png_byte)rmap[i];
palette[i].green = (png_byte)gmap[i];
palette[i].blue = (png_byte)bmap[i];
}
png_set_PLTE(png_ptr, info_ptr, palette, (int)ncolors);
FREE(rmap);
FREE(gmap);
FREE(bmap);
}
/* 0.4545 is treated as the default by some image
* display programs (not gqview). A value > 0.4545 will
* lighten an image as displayed by xv, display, etc. */
if (gamma > 0.0)
png_set_gAMA(png_ptr, info_ptr, (l_float64)gamma);
if ((text = pixGetText(pix))) {
png_text text_chunk;
text_chunk.compression = PNG_TEXT_COMPRESSION_NONE;
text_chunk.key = commentstring;
text_chunk.text = text;
text_chunk.text_length = strlen(text);
#ifdef PNG_ITXT_SUPPORTED
text_chunk.itxt_length = 0;
text_chunk.lang = NULL;
text_chunk.lang_key = NULL;
#endif
png_set_text(png_ptr, info_ptr, &text_chunk, 1);
}
/* Write header and palette info */
png_write_info(png_ptr, info_ptr);
if ((d != 32) && (d != 24)) { /* not rgb color */
/* Generate a temporary pix with bytes swapped.
* For a binary image, there are two conditions in
* which you must first invert the data for writing png:
* (a) no colormap
* (b) colormap with BLACK set to 0
* png writes binary with BLACK = 0, unless contradicted
* by a colormap. If the colormap has BLACK = "1"
* (typ. about 255), do not invert the data. If there
* is no colormap, you must invert the data to store
* in default BLACK = 0 state. */
if (d == 1 &&
(!cmap || (cmap && ((l_uint8 *)(cmap->array))[0] == 0x0))) {
pixt = pixInvert(NULL, pix);
pixEndianByteSwap(pixt);
}
else
pixt = pixEndianByteSwapNew(pix);
if (!pixt) {
png_destroy_write_struct(&png_ptr, &info_ptr);
return ERROR_INT("pixt not made", procName, 1);
}
/* Make and assign array of image row pointers */
if ((row_pointers = (png_bytep *)CALLOC(h, sizeof(png_bytep))) == NULL)
return ERROR_INT("row-pointers not made", procName, 1);
wpl = pixGetWpl(pixt);
data = pixGetData(pixt);
for (i = 0; i < h; i++)
row_pointers[i] = (png_bytep)(data + i * wpl);
png_set_rows(png_ptr, info_ptr, row_pointers);
/* Transfer the data */
png_write_image(png_ptr, row_pointers);
png_write_end(png_ptr, info_ptr);
if (cmflag)
FREE(palette);
FREE(row_pointers);
pixDestroy(&pixt);
png_destroy_write_struct(&png_ptr, &info_ptr);
return 0;
}
/* For rgb, compose and write a row at a time */
data = pixGetData(pix);
wpl = pixGetWpl(pix);
if (d == 24) { /* See note 7 above: special case of 24 bpp rgb */
for (i = 0; i < h; i++) {
ppixel = data + i * wpl;
png_write_rows(png_ptr, (png_bytepp)&ppixel, 1);
}
}
else { /* 32 bpp rgb and rgba */
if ((rowbuffer = (png_bytep)CALLOC(w, 4)) == NULL)
return ERROR_INT("rowbuffer not made", procName, 1);
for (i = 0; i < h; i++) {
ppixel = data + i * wpl;
for (j = k = 0; j < w; j++) {
rowbuffer[k++] = GET_DATA_BYTE(ppixel, COLOR_RED);
rowbuffer[k++] = GET_DATA_BYTE(ppixel, COLOR_GREEN);
rowbuffer[k++] = GET_DATA_BYTE(ppixel, COLOR_BLUE);
if (var_PNG_WRITE_ALPHA == 1)
rowbuffer[k++] = GET_DATA_BYTE(ppixel, L_ALPHA_CHANNEL);
ppixel++;
}
png_write_rows(png_ptr, &rowbuffer, 1);
}
FREE(rowbuffer);
}
png_write_end(png_ptr, info_ptr);
if (cmflag)
FREE(palette);
png_destroy_write_struct(&png_ptr, &info_ptr);
return 0;
}
