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Implement pdfioFileCreateImageObjFromData (Issue #15)

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Michael R Sweet 2021-07-17 20:54:29 -04:00
parent 47d6a34d07
commit 014c5dccba
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2 changed files with 194 additions and 3 deletions
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196
pdfio-content.c
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@ -1491,8 +1491,7 @@ pdfioFileCreateFontObjFromFile(
pdfioDictSetName(dict, "Subtype", "Type0");
pdfioDictSetName(dict, "BaseFont", basefont);
pdfioDictSetArray(dict, "DescendantFonts", descendants);
// pdfioDictSetName(dict, "Encoding", "Identity-H");
pdfioDictSetName(dict, "Encoding", "UniCNS-UCS2-H");
pdfioDictSetName(dict, "Encoding", "Identity-H");
if ((obj = pdfioFileCreateObj(pdf, dict)) == NULL)
return (NULL);
@ -1619,9 +1618,200 @@ pdfioFileCreateICCObjFromFile(
//
// 'pdfioFileCreateImageObjFromFile()' - Add an image object to a PDF file.
// 'pdfioFileCreateImageObjFromData()' - Add an image object to a PDF file from memory.
//
// This function creates an image object in a PDF file from a data buffer in
// memory. The "data" parameter points to the image data as 8-bit values. The
// "width" and "height" parameters specify the image dimensions. The
// "num_colors" parameter specifies the number of color components as follows:
//
// - 1 = grayscale
// - 2 = grayscale + alpha
// - 3 = RGB
// - 4 = RGBA
//
// The "color_data" parameter specifies an optional color space array for the
// image. The "interpolate" parameter specifies whether to interpolate when
// scaling the image on the page.
//
pdfio_obj_t * // O - Object
pdfioFileCreateImageObjFromData(
pdfio_file_t *pdf, // I - PDF file
const unsigned char *data, // I - Pointer to image data
size_t width, // I - Width of image
size_t height, // I - Height of image
int num_colors, // I - Number of colors
pdfio_array_t *color_data, // I - Colorspace data or `NULL` for default
bool interpolate) // I - Interpolate image data?
{
pdfio_dict_t *dict, // Image dictionary
*decode; // DecodeParms dictionary
pdfio_obj_t *obj, // Image object
*mask_obj = NULL;
// Mask image object, if any
pdfio_stream_t *st; // Image stream
size_t x, y, // X and Y position in image
linelen; // Line length
const unsigned char *dataptr; // Pointer into image data
unsigned char *line = NULL, // Current line
*lineptr; // Pointer into line
// Range check input...
if (!pdf || !data || !width || !height || num_colors < 1 || num_colors > 4)
return (NULL);
// Allocate memory for one line of data...
linelen = (num_colors < 3 ? 1 : 3) * width;
if ((line = malloc(linelen)) == NULL)
return (NULL);
// Generate a mask image, as needed...
if (!(num_colors & 1))
{
// Create the image mask dictionary...
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
free(line);
return (NULL);
}
pdfioDictSetName(dict, "Type", "XObject");
pdfioDictSetName(dict, "Subtype", "Image");
pdfioDictSetNumber(dict, "Width", width);
pdfioDictSetNumber(dict, "Height", height);
pdfioDictSetNumber(dict, "BitsPerComponent", 8);
pdfioDictSetBoolean(dict, "ImageMask", true);
if ((decode = pdfioDictCreate(pdf)) == NULL)
{
free(line);
return (NULL);
}
pdfioDictSetNumber(decode, "BitsPerComponent", 8);
pdfioDictSetNumber(decode, "Colors", num_colors - 1);
pdfioDictSetNumber(decode, "Columns", width);
pdfioDictSetNumber(decode, "Predictor", _PDFIO_PREDICTOR_PNG_AUTO);
pdfioDictSetDict(dict, "DecodeParms", decode);
// Create the mask object and write the mask image...
if ((mask_obj = pdfioFileCreateObj(pdf, dict)) == NULL)
{
free(line);
return (NULL);
}
if ((st = pdfioObjCreateStream(mask_obj, PDFIO_FILTER_FLATE)) == NULL)
{
free(line);
pdfioObjClose(mask_obj);
return (NULL);
}
for (y = height, dataptr = data + num_colors - 1; y > 0; y --)
{
for (x = width, lineptr = line; x > 0; x --, dataptr += num_colors)
*lineptr++ = *dataptr;
pdfioStreamWrite(st, line, width);
}
pdfioStreamClose(st);
}
// Now create the image...
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
free(line);
return (NULL);
}
pdfioDictSetName(dict, "Type", "XObject");
pdfioDictSetName(dict, "Subtype", "Image");
pdfioDictSetBoolean(dict, "Interpolate", interpolate);
pdfioDictSetNumber(dict, "Width", width);
pdfioDictSetNumber(dict, "Height", height);
pdfioDictSetNumber(dict, "BitsPerComponent", 8);
if (color_data)
pdfioDictSetArray(dict, "ColorSpace", color_data);
else
pdfioDictSetArray(dict, "ColorSpace", pdfioArrayCreateColorFromMatrix(pdf, num_colors < 3 ? 1 : 3, pdfioSRGBGamma, pdfioSRGBMatrix, pdfioSRGBWhitePoint));
if (mask_obj)
pdfioDictSetObj(dict, "SMask", mask_obj);
if ((decode = pdfioDictCreate(pdf)) == NULL)
{
free(line);
return (NULL);
}
pdfioDictSetNumber(decode, "BitsPerComponent", 8);
pdfioDictSetNumber(decode, "Colors", num_colors < 3 ? 1 : 3);
pdfioDictSetNumber(decode, "Columns", width);
pdfioDictSetNumber(decode, "Predictor", _PDFIO_PREDICTOR_PNG_AUTO);
pdfioDictSetDict(dict, "DecodeParms", decode);
if ((obj = pdfioFileCreateObj(pdf, dict)) == NULL)
{
free(line);
return (NULL);
}
if ((st = pdfioObjCreateStream(obj, PDFIO_FILTER_FLATE)) == NULL)
{
free(line);
pdfioObjClose(obj);
return (NULL);
}
for (y = height, dataptr = data; y > 0; y --)
{
switch (num_colors)
{
case 1 :
pdfioStreamWrite(st, dataptr, linelen);
dataptr += linelen;
break;
case 2 :
for (x = width, lineptr = line; x > 0; x --, dataptr += num_colors)
*lineptr++ = *dataptr;
pdfioStreamWrite(st, line, linelen);
break;
case 3 :
pdfioStreamWrite(st, dataptr, linelen);
dataptr += linelen;
break;
case 4 :
for (x = width, lineptr = line; x > 0; x --, dataptr += num_colors)
{
*lineptr++ = dataptr[0];
*lineptr++ = dataptr[1];
*lineptr++ = dataptr[2];
}
pdfioStreamWrite(st, line, linelen);
break;
}
}
free(line);
pdfioStreamClose(st);
return (obj);
}
//
// 'pdfioFileCreateImageObjFromFile()' - Add an image object to a PDF file from a file.
//
// This function creates an image object in a PDF file from a JPEG or PNG file.
// The "filename" parameter specifies the name of the JPEG or PNG file, while
// the "interpolate" parameter specifies whether to interpolate when scaling the
// image on the page.
//
// > Note: Currently PNG support is limited to grayscale, RGB, or indexed files
// > without interlacing or alpha. Transparency (masking) based on color/index

1
pdfio-content.h
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@ -147,6 +147,7 @@ extern bool pdfioContentTextShowJustified(pdfio_stream_t *st, bool unicode, siz
extern pdfio_obj_t *pdfioFileCreateFontObjFromBase(pdfio_file_t *pdf, const char *name) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreateFontObjFromFile(pdfio_file_t *pdf, const char *filename, bool unicode) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreateICCObjFromFile(pdfio_file_t *pdf, const char *filename, size_t num_colors) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreateImageObjFromData(pdfio_file_t *pdf, const unsigned char *data, size_t width, size_t height, int num_colors, pdfio_array_t *color_data, bool interpolate) PDFIO_PUBLIC;
extern pdfio_obj_t *pdfioFileCreateImageObjFromFile(pdfio_file_t *pdf, const char *filename, bool interpolate) PDFIO_PUBLIC;
// Image object helpers...