KIKIMR-19287: add task_stats_drawing script

1 files changed, 793 insertions, 0 deletions

diff --git a/contrib/python/matplotlib/py2/src/_png.cpp b/contrib/python/matplotlib/py2/src/_png.cpp
new file mode 100644
index 0000000000..1dcbf713f2
--- /dev/null
+++ b/contrib/python/matplotlib/py2/src/_png.cpp
@@ -0,0 +1,793 @@
+/* -*- mode: c++; c-basic-offset: 4 -*- */
+
+// this code is heavily adapted from the paint license, which is in
+// the file paint.license (BSD compatible) included in this
+// distribution.  TODO, add license file to MANIFEST.in and CVS
+
+/* For linux, png.h must be imported before Python.h because
+   png.h needs to be the one to define setjmp.
+   Undefining _POSIX_C_SOURCE and _XOPEN_SOURCE stops a couple
+   of harmless warnings.
+*/
+
+extern "C" {
+#   include <png.h>
+#   ifdef _POSIX_C_SOURCE
+#       undef _POSIX_C_SOURCE
+#   endif
+#   ifndef _AIX
+#   ifdef _XOPEN_SOURCE
+#       undef _XOPEN_SOURCE
+#   endif
+#   endif
+}
+
+#include "numpy_cpp.h"
+#include "mplutils.h"
+#include "file_compat.h"
+
+#   include <vector>
+#   include "Python.h"
+
+
+// As reported in [3082058] build _png.so on aix
+#ifdef _AIX
+#undef jmpbuf
+#endif
+
+struct buffer_t {
+    PyObject *str;
+    size_t cursor;
+    size_t size;
+};
+
+
+static void write_png_data_buffer(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+    buffer_t *buff = (buffer_t *)png_get_io_ptr(png_ptr);
+    if (buff->cursor + length < buff->size) {
+        memcpy(PyBytes_AS_STRING(buff->str) + buff->cursor, data, length);
+        buff->cursor += length;
+    }
+}
+
+static void flush_png_data_buffer(png_structp png_ptr)
+{
+
+}
+
+static void write_png_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+    PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr);
+    PyObject *write_method = PyObject_GetAttrString(py_file_obj, "write");
+    PyObject *result = NULL;
+    if (write_method) {
+#if PY3K
+        result = PyObject_CallFunction(write_method, (char *)"y#", data, length);
+#else
+        result = PyObject_CallFunction(write_method, (char *)"s#", data, length);
+#endif
+    }
+    Py_XDECREF(write_method);
+    Py_XDECREF(result);
+}
+
+static void flush_png_data(png_structp png_ptr)
+{
+    PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr);
+    PyObject *flush_method = PyObject_GetAttrString(py_file_obj, "flush");
+    PyObject *result = NULL;
+    if (flush_method) {
+        result = PyObject_CallFunction(flush_method, (char *)"");
+    }
+    Py_XDECREF(flush_method);
+    Py_XDECREF(result);
+}
+
+const char *Py_write_png__doc__ =
+    "write_png(buffer, file, dpi=0, compression=6, filter=auto, metadata=None)\n"
+    "\n"
+    "Parameters\n"
+    "----------\n"
+    "buffer : numpy array of image data\n"
+    "    Must be an MxNxD array of dtype uint8.\n"
+    "    - if D is 1, the image is greyscale\n"
+    "    - if D is 3, the image is RGB\n"
+    "    - if D is 4, the image is RGBA\n"
+    "\n"
+    "file : str path, file-like object or None\n"
+    "    - If a str, must be a file path\n"
+    "    - If a file-like object, must write bytes\n"
+    "    - If None, a byte string containing the PNG data will be returned\n"
+    "\n"
+    "dpi : float\n"
+    "    The dpi to store in the file metadata.\n"
+    "\n"
+    "compression : int\n"
+    "    The level of lossless zlib compression to apply.  0 indicates no\n"
+    "    compression.  Values 1-9 indicate low/fast through high/slow\n"
+    "    compression.  Default is 6.\n"
+    "\n"
+    "filter : int\n"
+    "    Filter to apply.  Must be one of the constants: PNG_FILTER_NONE,\n"
+    "    PNG_FILTER_SUB, PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH.\n"
+    "    See the PNG standard for more information.\n"
+    "    If not provided, libpng will try to automatically determine the\n"
+    "    best filter on a line-by-line basis.\n"
+    "\n"
+    "metadata : dictionary\n"
+    "    The keyword-text pairs that are stored as comments in the image.\n"
+    "    Keys must be shorter than 79 chars. The only supported encoding\n"
+    "    for both keywords and values is Latin-1 (ISO 8859-1).\n"
+    "    Examples given in the PNG Specification are:\n"
+    "    - Title: Short (one line) title or caption for image\n"
+    "    - Author: Name of image's creator\n"
+    "    - Description: Description of image (possibly long)\n"
+    "    - Copyright: Copyright notice\n"
+    "    - Creation Time: Time of original image creation\n"
+    "                     (usually RFC 1123 format, see below)\n"
+    "    - Software: Software used to create the image\n"
+    "    - Disclaimer: Legal disclaimer\n"
+    "    - Warning: Warning of nature of content\n"
+    "    - Source: Device used to create the image\n"
+    "    - Comment: Miscellaneous comment; conversion\n"
+    "               from other image format\n"
+    "\n"
+    "Returns\n"
+    "-------\n"
+    "buffer : bytes or None\n"
+    "    Byte string containing the PNG content if None was passed in for\n"
+    "    file, otherwise None is returned.\n";
+
+static PyObject *Py_write_png(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    numpy::array_view<unsigned char, 3> buffer;
+    PyObject *filein;
+    PyObject *metadata = NULL;
+    PyObject *meta_key, *meta_val;
+    png_text *text;
+    Py_ssize_t pos = 0;
+    int meta_pos = 0;
+    Py_ssize_t meta_size;
+    double dpi = 0;
+    int compression = 6;
+    int filter = -1;
+    const char *names[] = { "buffer", "file", "dpi", "compression", "filter", "metadata", NULL };
+
+    // We don't need strict contiguity, just for each row to be
+    // contiguous, and libpng has special handling for getting RGB out
+    // of RGBA, ARGB or BGR. But the simplest thing to do is to
+    // enforce contiguity using array_view::converter_contiguous.
+    if (!PyArg_ParseTupleAndKeywords(args,
+                                     kwds,
+                                     "O&O|diiO:write_png",
+                                     (char **)names,
+                                     &buffer.converter_contiguous,
+                                     &buffer,
+                                     &filein,
+                                     &dpi,
+                                     &compression,
+                                     &filter,
+                                     &metadata)) {
+        return NULL;
+    }
+
+    png_uint_32 width = (png_uint_32)buffer.dim(1);
+    png_uint_32 height = (png_uint_32)buffer.dim(0);
+    int channels = buffer.dim(2);
+    std::vector<png_bytep> row_pointers(height);
+    for (png_uint_32 row = 0; row < (png_uint_32)height; ++row) {
+        row_pointers[row] = (png_bytep)&buffer(row, 0, 0);
+    }
+
+    FILE *fp = NULL;
+    mpl_off_t offset = 0;
+    bool close_file = false;
+    bool close_dup_file = false;
+    PyObject *py_file = NULL;
+
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+    struct png_color_8_struct sig_bit;
+    int png_color_type;
+    buffer_t buff;
+    buff.str = NULL;
+
+    switch (channels) {
+    case 1:
+        png_color_type = PNG_COLOR_TYPE_GRAY;
+        break;
+    case 3:
+        png_color_type = PNG_COLOR_TYPE_RGB;
+        break;
+    case 4:
+        png_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+        break;
+    default:
+        PyErr_SetString(PyExc_ValueError,
+                        "Buffer must be an NxMxD array with D in 1, 3, 4 "
+                        "(grayscale, RGB, RGBA)");
+        goto exit;
+    }
+
+    if (compression < 0 || compression > 9) {
+        PyErr_Format(PyExc_ValueError,
+                     "compression must be in range 0-9, got %d", compression);
+        goto exit;
+    }
+
+    if (PyBytes_Check(filein) || PyUnicode_Check(filein)) {
+        if ((py_file = mpl_PyFile_OpenFile(filein, (char *)"wb")) == NULL) {
+            goto exit;
+        }
+        close_file = true;
+    } else {
+        py_file = filein;
+    }
+
+    if (filein == Py_None) {
+        buff.size = width * height * 4 + 1024;
+        buff.str = PyBytes_FromStringAndSize(NULL, buff.size);
+        if (buff.str == NULL) {
+            goto exit;
+        }
+        buff.cursor = 0;
+    } else {
+        #if PY3K
+        if (close_file) {
+        #else
+        if (close_file || PyFile_Check(py_file)) {
+        #endif
+            fp = mpl_PyFile_Dup(py_file, (char *)"wb", &offset);
+        }
+
+        if (fp) {
+            close_dup_file = true;
+        } else {
+            PyErr_Clear();
+            PyObject *write_method = PyObject_GetAttrString(py_file, "write");
+            if (!(write_method && PyCallable_Check(write_method))) {
+                Py_XDECREF(write_method);
+                PyErr_SetString(PyExc_TypeError,
+                                "Object does not appear to be a 8-bit string path or "
+                                "a Python file-like object");
+                goto exit;
+            }
+            Py_XDECREF(write_method);
+        }
+    }
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (png_ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError, "Could not create write struct");
+        goto exit;
+    }
+
+    png_set_compression_level(png_ptr, compression);
+    if (filter >= 0) {
+        png_set_filter(png_ptr, 0, filter);
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (info_ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError, "Could not create info struct");
+        goto exit;
+    }
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        PyErr_SetString(PyExc_RuntimeError, "libpng signaled error");
+        goto exit;
+    }
+
+    if (buff.str) {
+        png_set_write_fn(png_ptr, (void *)&buff, &write_png_data_buffer, &flush_png_data_buffer);
+    } else if (fp) {
+        png_init_io(png_ptr, fp);
+    } else {
+        png_set_write_fn(png_ptr, (void *)py_file, &write_png_data, &flush_png_data);
+    }
+    png_set_IHDR(png_ptr,
+                 info_ptr,
+                 width,
+                 height,
+                 8,
+                 png_color_type,
+                 PNG_INTERLACE_NONE,
+                 PNG_COMPRESSION_TYPE_BASE,
+                 PNG_FILTER_TYPE_BASE);
+
+    // Save the dpi of the image in the file
+    if (dpi > 0.0) {
+        png_uint_32 dots_per_meter = (png_uint_32)(dpi / (2.54 / 100.0));
+        png_set_pHYs(png_ptr, info_ptr, dots_per_meter, dots_per_meter, PNG_RESOLUTION_METER);
+    }
+
+#ifdef PNG_TEXT_SUPPORTED
+    // Save the metadata
+    if (metadata != NULL) {
+        meta_size = PyDict_Size(metadata);
+        text = new png_text[meta_size];
+
+        while (PyDict_Next(metadata, &pos, &meta_key, &meta_val)) {
+            text[meta_pos].compression = PNG_TEXT_COMPRESSION_NONE;
+#if PY3K
+            if (PyUnicode_Check(meta_key)) {
+                PyObject *temp_key = PyUnicode_AsEncodedString(meta_key, "latin_1", "strict");
+                if (temp_key != NULL) {
+                    text[meta_pos].key = PyBytes_AsString(temp_key);
+                }
+            } else if (PyBytes_Check(meta_key)) {
+                text[meta_pos].key = PyBytes_AsString(meta_key);
+            } else {
+                char invalid_key[79];
+                sprintf(invalid_key,"INVALID KEY %d", meta_pos);
+                text[meta_pos].key = invalid_key;
+            }
+            if (PyUnicode_Check(meta_val)) {
+                PyObject *temp_val = PyUnicode_AsEncodedString(meta_val, "latin_1", "strict");
+                if (temp_val != NULL) {
+                    text[meta_pos].text = PyBytes_AsString(temp_val);
+                }
+            } else if (PyBytes_Check(meta_val)) {
+                text[meta_pos].text = PyBytes_AsString(meta_val);
+            } else {
+                text[meta_pos].text = (char *)"Invalid value in metadata";
+            }
+#else
+            text[meta_pos].key = PyString_AsString(meta_key);
+            text[meta_pos].text = PyString_AsString(meta_val);
+#endif
+#ifdef PNG_iTXt_SUPPORTED
+            text[meta_pos].lang = NULL;
+#endif
+            meta_pos++;
+        }
+        png_set_text(png_ptr, info_ptr, text, meta_size);
+        delete[] text;
+    }
+#endif
+
+    sig_bit.alpha = 0;
+    switch (png_color_type) {
+    case PNG_COLOR_TYPE_GRAY:
+        sig_bit.gray = 8;
+        sig_bit.red = 0;
+        sig_bit.green = 0;
+        sig_bit.blue = 0;
+        break;
+    case PNG_COLOR_TYPE_RGB_ALPHA:
+        sig_bit.alpha = 8;
+        // fall through
+    case PNG_COLOR_TYPE_RGB:
+        sig_bit.gray = 0;
+        sig_bit.red = 8;
+        sig_bit.green = 8;
+        sig_bit.blue = 8;
+        break;
+    default:
+        PyErr_SetString(PyExc_RuntimeError, "internal error, bad png_color_type");
+        goto exit;
+    }
+    png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+
+    png_write_info(png_ptr, info_ptr);
+    png_write_image(png_ptr, &row_pointers[0]);
+    png_write_end(png_ptr, info_ptr);
+
+exit:
+
+    if (png_ptr && info_ptr) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+    }
+
+    if (close_dup_file) {
+        mpl_PyFile_DupClose(py_file, fp, offset);
+    }
+
+    if (close_file) {
+        mpl_PyFile_CloseFile(py_file);
+        Py_DECREF(py_file);
+    }
+
+    if (PyErr_Occurred()) {
+        Py_XDECREF(buff.str);
+        return NULL;
+    } else {
+        if (buff.str) {
+            _PyBytes_Resize(&buff.str, buff.cursor);
+            return buff.str;
+        }
+        Py_RETURN_NONE;
+    }
+}
+
+static void _read_png_data(PyObject *py_file_obj, png_bytep data, png_size_t length)
+{
+    PyObject *read_method = PyObject_GetAttrString(py_file_obj, "read");
+    PyObject *result = NULL;
+    char *buffer;
+    Py_ssize_t bufflen;
+    if (read_method) {
+        result = PyObject_CallFunction(read_method, (char *)"i", length);
+        if (result) {
+            if (PyBytes_AsStringAndSize(result, &buffer, &bufflen) == 0) {
+                if (bufflen == (Py_ssize_t)length) {
+                    memcpy(data, buffer, length);
+                } else {
+                    PyErr_SetString(PyExc_IOError, "read past end of file");
+                }
+            } else {
+                PyErr_SetString(PyExc_IOError, "failed to copy buffer");
+            }
+        } else  {
+            PyErr_SetString(PyExc_IOError, "failed to read file");
+        }
+
+
+    }
+    Py_XDECREF(read_method);
+    Py_XDECREF(result);
+}
+
+static void read_png_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+    PyObject *py_file_obj = (PyObject *)png_get_io_ptr(png_ptr);
+    _read_png_data(py_file_obj, data, length);
+    if (PyErr_Occurred()) {
+        png_error(png_ptr, "failed to read file");
+    }
+
+}
+
+static PyObject *_read_png(PyObject *filein, bool float_result)
+{
+    png_byte header[8]; // 8 is the maximum size that can be checked
+    FILE *fp = NULL;
+    mpl_off_t offset = 0;
+    bool close_file = false;
+    bool close_dup_file = false;
+    PyObject *py_file = NULL;
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+    int num_dims;
+    std::vector<png_bytep> row_pointers;
+    png_uint_32 width = 0;
+    png_uint_32 height = 0;
+    int bit_depth;
+    PyObject *result = NULL;
+
+    // TODO: Remove direct calls to Numpy API here
+
+    if (PyBytes_Check(filein) || PyUnicode_Check(filein)) {
+        if ((py_file = mpl_PyFile_OpenFile(filein, (char *)"rb")) == NULL) {
+            goto exit;
+        }
+        close_file = true;
+    } else {
+        py_file = filein;
+    }
+
+    #if PY3K
+    if (close_file) {
+    #else
+    if (close_file || PyFile_Check(py_file)) {
+    #endif
+        fp = mpl_PyFile_Dup(py_file, (char *)"rb", &offset);
+    }
+
+    if (fp) {
+        close_dup_file = true;
+        if (fread(header, 1, 8, fp) != 8) {
+            PyErr_SetString(PyExc_IOError, "error reading PNG header");
+            goto exit;
+        }
+    } else {
+        PyErr_Clear();
+
+        PyObject *read_method = PyObject_GetAttrString(py_file, "read");
+        if (!(read_method && PyCallable_Check(read_method))) {
+            Py_XDECREF(read_method);
+            PyErr_SetString(PyExc_TypeError,
+                            "Object does not appear to be a 8-bit string path or "
+                            "a Python file-like object");
+            goto exit;
+        }
+        Py_XDECREF(read_method);
+        _read_png_data(py_file, header, 8);
+        if (PyErr_Occurred()) {
+            goto exit;
+        }
+    }
+
+    if (png_sig_cmp(header, 0, 8)) {
+        PyErr_SetString(PyExc_ValueError, "invalid PNG header");
+        goto exit;
+    }
+
+    /* initialize stuff */
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+
+    if (!png_ptr) {
+        PyErr_SetString(PyExc_RuntimeError, "png_create_read_struct failed");
+        goto exit;
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        PyErr_SetString(PyExc_RuntimeError, "png_create_info_struct failed");
+        goto exit;
+    }
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_RuntimeError, "error setting jump");
+        }
+        goto exit;
+    }
+
+    if (fp) {
+        png_init_io(png_ptr, fp);
+    } else {
+        png_set_read_fn(png_ptr, (void *)py_file, &read_png_data);
+    }
+    png_set_sig_bytes(png_ptr, 8);
+    png_read_info(png_ptr, info_ptr);
+
+    width = png_get_image_width(png_ptr, info_ptr);
+    height = png_get_image_height(png_ptr, info_ptr);
+
+    bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+
+    // Unpack 1, 2, and 4-bit images
+    if (bit_depth < 8) {
+        png_set_packing(png_ptr);
+    }
+
+    // If sig bits are set, shift data
+    png_color_8p sig_bit;
+    if ((png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_PALETTE) &&
+        png_get_sBIT(png_ptr, info_ptr, &sig_bit)) {
+        png_set_shift(png_ptr, sig_bit);
+    }
+
+#if NPY_BYTE_ORDER == NPY_LITTLE_ENDIAN
+    // Convert big endian to little
+    if (bit_depth == 16) {
+        png_set_swap(png_ptr);
+    }
+#endif
+
+    // Convert palletes to full RGB
+    if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE) {
+        png_set_palette_to_rgb(png_ptr);
+        bit_depth = 8;
+    }
+
+    // If there's an alpha channel convert gray to RGB
+    if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_GRAY_ALPHA) {
+        png_set_gray_to_rgb(png_ptr);
+    }
+
+    png_set_interlace_handling(png_ptr);
+    png_read_update_info(png_ptr, info_ptr);
+
+    row_pointers.resize(height);
+    for (png_uint_32 row = 0; row < height; row++) {
+        row_pointers[row] = new png_byte[png_get_rowbytes(png_ptr, info_ptr)];
+    }
+
+    png_read_image(png_ptr, &row_pointers[0]);
+
+    npy_intp dimensions[3];
+    dimensions[0] = height; // numrows
+    dimensions[1] = width; // numcols
+    if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_ALPHA) {
+        dimensions[2] = 4; // RGBA images
+    } else if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_COLOR) {
+        dimensions[2] = 3; // RGB images
+    } else {
+        dimensions[2] = 1; // Greyscale images
+    }
+
+    if (float_result) {
+        double max_value = (1 << bit_depth) - 1;
+
+        numpy::array_view<float, 3> A(dimensions);
+
+        for (png_uint_32 y = 0; y < height; y++) {
+            png_byte *row = row_pointers[y];
+            for (png_uint_32 x = 0; x < width; x++) {
+                if (bit_depth == 16) {
+                    png_uint_16 *ptr = &reinterpret_cast<png_uint_16 *>(row)[x * dimensions[2]];
+                    for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) {
+                        A(y, x, p) = (float)(ptr[p]) / max_value;
+                    }
+                } else {
+                    png_byte *ptr = &(row[x * dimensions[2]]);
+                    for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) {
+                        A(y, x, p) = (float)(ptr[p]) / max_value;
+                    }
+                }
+            }
+        }
+
+        result = A.pyobj();
+    } else if (bit_depth == 16) {
+        numpy::array_view<png_uint_16, 3> A(dimensions);
+
+        for (png_uint_32 y = 0; y < height; y++) {
+            png_byte *row = row_pointers[y];
+            for (png_uint_32 x = 0; x < width; x++) {
+                png_uint_16 *ptr = &reinterpret_cast<png_uint_16 *>(row)[x * dimensions[2]];
+                for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) {
+                    A(y, x, p) = ptr[p];
+                }
+            }
+        }
+
+        result = A.pyobj();
+    } else if (bit_depth == 8) {
+        numpy::array_view<png_byte, 3> A(dimensions);
+
+        for (png_uint_32 y = 0; y < height; y++) {
+            png_byte *row = row_pointers[y];
+            for (png_uint_32 x = 0; x < width; x++) {
+                png_byte *ptr = &(row[x * dimensions[2]]);
+                for (png_uint_32 p = 0; p < (png_uint_32)dimensions[2]; p++) {
+                    A(y, x, p) = ptr[p];
+                }
+            }
+        }
+
+        result = A.pyobj();
+    } else {
+        PyErr_SetString(PyExc_RuntimeError, "image has unknown bit depth");
+        goto exit;
+    }
+
+    // free the png memory
+    png_read_end(png_ptr, info_ptr);
+
+    // For gray, return an x by y array, not an x by y by 1
+    num_dims = (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_COLOR) ? 3 : 2;
+
+    if (num_dims == 2) {
+        PyArray_Dims dims = {dimensions, 2};
+        PyObject *reshaped = PyArray_Newshape((PyArrayObject *)result, &dims, NPY_CORDER);
+        Py_DECREF(result);
+        result = reshaped;
+    }
+
+exit:
+    if (png_ptr && info_ptr) {
+#ifndef png_infopp_NULL
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+#else
+        png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+#endif
+    }
+
+    if (close_dup_file) {
+        mpl_PyFile_DupClose(py_file, fp, offset);
+    }
+
+    if (close_file) {
+        mpl_PyFile_CloseFile(py_file);
+        Py_DECREF(py_file);
+    }
+
+    for (png_uint_32 row = 0; row < height; row++) {
+        delete[] row_pointers[row];
+    }
+
+    if (PyErr_Occurred()) {
+        Py_XDECREF(result);
+        return NULL;
+    } else {
+        return result;
+    }
+}
+
+const char *Py_read_png_float__doc__ =
+    "read_png_float(file)\n"
+    "\n"
+    "Read in a PNG file, converting values to floating-point doubles\n"
+    "in the range (0, 1)\n"
+    "\n"
+    "Parameters\n"
+    "----------\n"
+    "file : str path or file-like object\n";
+
+static PyObject *Py_read_png_float(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    return _read_png(args, true);
+}
+
+const char *Py_read_png_int__doc__ =
+    "read_png_int(file)\n"
+    "\n"
+    "Read in a PNG file with original integer values.\n"
+    "\n"
+    "Parameters\n"
+    "----------\n"
+    "file : str path or file-like object\n";
+
+static PyObject *Py_read_png_int(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    return _read_png(args, false);
+}
+
+const char *Py_read_png__doc__ =
+    "read_png(file)\n"
+    "\n"
+    "Read in a PNG file, converting values to floating-point doubles\n"
+    "in the range (0, 1)\n"
+    "\n"
+    "Alias for read_png_float()\n"
+    "\n"
+    "Parameters\n"
+    "----------\n"
+    "file : str path or file-like object\n";
+
+static PyMethodDef module_methods[] = {
+    {"write_png", (PyCFunction)Py_write_png, METH_VARARGS|METH_KEYWORDS, Py_write_png__doc__},
+    {"read_png", (PyCFunction)Py_read_png_float, METH_O, Py_read_png__doc__},
+    {"read_png_float", (PyCFunction)Py_read_png_float, METH_O, Py_read_png_float__doc__},
+    {"read_png_int", (PyCFunction)Py_read_png_int, METH_O, Py_read_png_int__doc__},
+    {NULL}
+};
+
+extern "C" {
+
+#if PY3K
+    static struct PyModuleDef moduledef = {
+        PyModuleDef_HEAD_INIT,
+        "_png",
+        NULL,
+        0,
+        module_methods,
+        NULL,
+        NULL,
+        NULL,
+        NULL
+    };
+
+#define INITERROR return NULL
+
+    PyMODINIT_FUNC PyInit__png(void)
+
+#else
+#define INITERROR return
+
+    PyMODINIT_FUNC init_png(void)
+#endif
+
+    {
+        PyObject *m;
+
+#if PY3K
+        m = PyModule_Create(&moduledef);
+#else
+        m = Py_InitModule3("_png", module_methods, NULL);
+#endif
+
+        if (m == NULL) {
+            INITERROR;
+        }
+
+        import_array();
+
+        if (PyModule_AddIntConstant(m, "PNG_FILTER_NONE", PNG_FILTER_NONE) ||
+            PyModule_AddIntConstant(m, "PNG_FILTER_SUB", PNG_FILTER_SUB) ||
+            PyModule_AddIntConstant(m, "PNG_FILTER_UP", PNG_FILTER_UP) ||
+            PyModule_AddIntConstant(m, "PNG_FILTER_AVG", PNG_FILTER_AVG) ||
+            PyModule_AddIntConstant(m, "PNG_FILTER_PAETH", PNG_FILTER_PAETH)) {
+            INITERROR;
+        }
+
+
+#if PY3K
+        return m;
+#endif
+    }
+}