pygame2.sdlext.surfarray – module for accessing surface pixel data using numeric array interfaces

Functions to convert pixel data between pygame Surfaces and arrays. This module will only be functional when pygame can use the external Numpy or Numeric packages.

Every pixel is stored as a single integer value to represent the red, green, and blue colors. The 8bit images use a value that looks into a colormap. Pixels with higher depth use a bit packing process to place three or four values into a single number.

The arrays are indexed by the X axis first, followed by the Y axis. Arrays that treat the pixels as a single integer are referred to as 2D arrays. This module can also separate the red, green, and blue color values into separate indices. These types of arrays are referred to as 3D arrays, and the last index is 0 for red, 1 for green, and 2 for blue.

Supported array types are

  • numeric
  • numpy

The default will be Numeric, if installed. Otherwise, numpy will be set as default if installed. If neither Numeric nor numpy are installed, the module will raise an ImportError.

The array type to use can be changed at runtime using the use_arraytype() method, which requires one of the above types as string.

Note

numpy and Numeric are not completely compatible. Certain array manipulations, which work for one type, might behave differently or even completely break for the other.

Additionally, in contrast to Numeric numpy does use unsigned 16-bit integers. Images with 16-bit data will be treated as unsigned integers. Numeric instead uses signed integers for the representation, which is important to keep in mind, if you use the module’s functions and wonder about the values.

Module Functions

pygame2.sdlext.surfarray.array2d(Surface) → array

Copy pixels into a 2d array.

Copy the pixels from a Surface into a 2D array. The bit depth of the surface will control the size of the integer values, and will work for any type of pixel format.

This function will temporarily lock the Surface as pixels are copied (see the Surface.lock - lock the Surface memory for pixel access method).

pygame2.sdlext.surfarray.array3d(Surface) → array

Copy pixels into a 3d array.

Copy the pixels from a Surface into a 3D array. The bit depth of the surface will control the size of the integer values, and will work for any type of pixel format.

This function will temporarily lock the Surface as pixels are copied (see the Surface.lock - lock the Surface memory for pixel access method).

pygame2.sdlext.surfarray.array_alpha(Surface) → array

Copy pixel alphas into a 2d array.

Copy the pixel alpha values (degree of transparency) from a Surface into a 2D array. This will work for any type of Surface format. Surfaces without a pixel alpha will return an array with all opaque values.

This function will temporarily lock the Surface as pixels are copied (see the Surface.lock - lock the Surface memory for pixel access method).

pygame2.sdlext.surfarray.array_colorkey(Surface) → array

Copy the colorkey values into a 2d array.

Create a new array with the colorkey transparency value from each pixel. If the pixel matches the colorkey it will be fully transparent; otherwise it will be fully opaque.

This will work on any type of Surface format. If the image has no colorkey a solid opaque array will be returned.

This function will temporarily lock the Surface as pixels are copied.

pygame2.sdlext.surfarray.blit_array(Surface, array) → None

Blit directly from a array values.

Directly copy values from an array into a Surface. This is faster than converting the array into a Surface and blitting. The array must be the same dimensions as the Surface and will completely replace all pixel values.

This function will temporarily lock the Surface as the new values are copied.

pygame2.sdlext.surfarray.get_arraytype() → str

Gets the currently active array type.

Returns the currently active array type. This will be a value of the get_arraytypes() tuple and indicates which type of array module is used for the array creation.

pygame2.sdlext.surfarray.get_arraytypes() → tuple

Gets the array system types currently supported.

Checks, which array system types are available and returns them as a tuple of strings. The values of the tuple can be used directly in the use_arraytype () method.

If no supported array system could be found, None will be returned.

pygame2.sdlext.surfarray.make_surface(array) → Surface

Copy an array to a new surface.

Create a new Surface that best resembles the data and format on the array. The array can be 2D or 3D with any sized integer values.

pygame2.sdlext.surfarray.map_array(Surface, array3d) → array2d

Map a 3D array into a 2D array.

Convert a 3D array into a 2D array. This will use the given Surface format to control the conversion. Palette surface formats are not supported.

pygame2.sdlext.surfarray.pixels2d(Surface) → array

Reference pixels into a 2d array.

Create a new 2D array that directly references the pixel values in a Surface. Any changes to the array will affect the pixels in the Surface. This is a fast operation since no data is copied.

Pixels from a 24-bit Surface cannot be referenced, but all other Surface bit depths can.

The Surface this references will remain locked for the lifetime of the array (see the Surface.lock - lock the Surface memory for pixel access method).

pygame2.sdlext.surfarray.pixels3d(Surface) → array

Reference pixels into a 3d array.

Create a new 3D array that directly references the pixel values in a Surface. Any changes to the array will affect the pixels in the Surface. This is a fast operation since no data is copied.

This will only work on Surfaces that have 24-bit or 32-bit formats. Lower pixel formats cannot be referenced.

The Surface this references will remain locked for the lifetime of the array (see the Surface.lock - lock the Surface memory for pixel access method).

pygame2.sdlext.surfarray.pixels_alpha(Surface) → array

Reference pixel alphas into a 2d array.

Create a new 2D array that directly references the alpha values (degree of transparency) in a Surface. Any changes to the array will affect the pixels in the Surface. This is a fast operation since no data is copied.

This can only work on 32-bit Surfaces with a per-pixel alpha value.

The Surface this array references will remain locked for the lifetime of the array.

pygame2.sdlext.surfarray.use_arraytype(arraytype) → None

Sets the array system to be used for surface arrays.

Uses the requested array type for the module functions. Currently supported array types are:

  • numeric
  • numpy

If the requested type is not available, a ValueError will be raised.