PNMImage

from panda3d.core import PNMImage

class PNMImage

Bases:

Bases: PNMImageHeader

The name of this class derives from the fact that we originally implemented it as a layer on top of the “pnm library”, based on netpbm, which was built to implement pbm, pgm, and pbm files, and is the underlying support of a number of public-domain image file converters. Nowadays we are no longer derived directly from the pnm library, mainly to allow support of C++ iostreams instead of the C stdio FILE interface.

Conceptually, a PNMImage is a two-dimensional array of xels, which are the PNM-defined generic pixel type. Each xel may have a red, green, and blue component, or (if the image is grayscale) a gray component. The image may be read in, the individual xels manipulated, and written out again, or a black image may be constructed from scratch.

A PNMImage has a color space and a maxval, the combination of which defines how a floating-point linear color value is encoded as an integer value in memory. The functions ending in _val operate on encoded colors, whereas the regular ones work with linear floating-point values. All operations are color space correct unless otherwise specified.

The image is of size XSize() by YSize() xels, numbered from top to bottom, left to right, beginning at zero.

Files can be specified by filename, or by an iostream pointer. The filename “-” refers to stdin or stdout.

This class is not inherently thread-safe; use it from a single thread or protect access using a mutex.

Inheritance diagram

class CRow

Bases:

Provides an accessor for reading the contents of one row of the image in- place.

__getitem__(x: int) → LColorf

__init__(param0: CRow)

get_alpha_val(x: int) → int: Fetch the alpha value at the given column in the row.

get_xel_val(x: int) → xel: Fetch the pixel at the given column in the row.

size() → int: Get the number of pixels in the row.

class Row

Bases:

Provides an accessor for reading or writing the contents of one row of the image in-place.

__getitem__(x: int) → LColorf

__init__(param0: Row)

__setitem__(x: int, v: LColorf): Set the pixel at the given column in the row. If the image has no alpha channel, the alpha component is ignored.

get_alpha_val(x: int) → int: Fetch the alpha value at the given column in the row.

get_xel_val(x: int) → xel: Fetch the pixel at the given column in the row.

set_alpha_val(x: int, v: int): Set the alpha value at the given column in the row.

set_xel_val(x: int, v: xel): Set the pixel at the given column in the row.

size() → int: Get the number of pixels in the row.

__add__(other: LColorf) → PNMImage

__add__(other: PNMImage) → PNMImage

__getitem__(y: int) → Row

__getitem__(y: int) → CRow

__iadd__(other: LColorf) → PNMImage

__iadd__(other: PNMImage) → PNMImage

__imul__(other: LColorf) → PNMImage

__imul__(other: PNMImage) → PNMImage

__imul__(multiplier: float) → PNMImage

__init__()

__init__(filename: Filename, type: PNMFileType)

__init__(copy: PNMImage)

__init__(x_size: int, y_size: int, num_channels: int, maxval: int, type: PNMFileType, color_space: ColorSpace)

__isub__(other: LColorf) → PNMImage

__isub__(other: PNMImage) → PNMImage

__mul__(other: LColorf) → PNMImage

__mul__(other: PNMImage) → PNMImage

__mul__(multiplier: float) → PNMImage

__sub__(other: LColorf) → PNMImage

__sub__(other: PNMImage) → PNMImage

add_alpha(): Adds an alpha channel to the image, if it does not already have one. The alpha channel is initialized to zeros.

add_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int, pixel_scale: float): Behaves like copy_sub_image(), except the copy pixels are added to the pixels of the destination, after scaling by the specified pixel_scale. Unlike blend_sub_image(), the alpha channel is not treated specially.

alpha_fill(alpha: float): Sets the entire alpha channel to the given level.

alpha_fill_val(alpha: int): Sets the entire alpha channel to the given level.

apply_exponent(gray_exponent: float): Adjusts each channel of the image by raising the corresponding component value to the indicated exponent, such that L’ = L ^ exponent.

apply_exponent(gray_exponent: float, alpha_exponent: float): Adjusts each channel of the image by raising the corresponding component value to the indicated exponent, such that L’ = L ^ exponent.

apply_exponent(red_exponent: float, green_exponent: float, blue_exponent: float): Adjusts each channel of the image by raising the corresponding component value to the indicated exponent, such that L’ = L ^ exponent. For a grayscale image, the blue_exponent value is used for the grayscale value, and red_exponent and green_exponent are unused.

apply_exponent(red_exponent: float, green_exponent: float, blue_exponent: float, alpha_exponent: float): Adjusts each channel of the image by raising the corresponding component value to the indicated exponent, such that L’ = L ^ exponent. For a grayscale image, the blue_exponent value is used for the grayscale value, and red_exponent and green_exponent are unused.

assign(copy: PNMImage) → PNMImage

blend(x: int, y: int, val: LRGBColorf, alpha: float): Smoothly blends the indicated pixel value in with whatever was already in the image, based on the given alpha value. An alpha of 1.0 is fully opaque and completely replaces whatever was there previously; alpha of 0.0 is fully transparent and does nothing.

blend(x: int, y: int, r: float, g: float, b: float, alpha: float): Smoothly blends the indicated pixel value in with whatever was already in the image, based on the given alpha value. An alpha of 1.0 is fully opaque and completely replaces whatever was there previously; alpha of 0.0 is fully transparent and does nothing.

blend_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int, pixel_scale: float)

Behaves like copy_sub_image(), except the alpha channel of the copy is used to blend the copy into the destination image, instead of overwriting pixels unconditionally.

If pixel_scale is not 1.0, it specifies an amount to scale each alpha value of the source image before applying it to the target image.

If pixel_scale is 1.0 and the copy has no alpha channel, this degenerates into copy_sub_image().

box_filter(radius: float): This flavor of box_filter() will apply the filter over the entire image without resizing or copying; the effect is that of a blur operation.

box_filter_from(radius: float, copy: PNMImage): Makes a resized copy of the indicated image into this one using the indicated filter. The image to be copied is squashed and stretched to match the dimensions of the current image, applying the appropriate filter to perform the stretching.

clamp_val(input_value: int) → int: A handy function to clamp values to [0..get_maxval()].

clear(): Frees all memory allocated for the image, and clears all its parameters (size, color, type, etc).

clear(x_size: int, y_size: int, num_channels: int, maxval: int, type: PNMFileType, color_space: ColorSpace): This flavor of clear() reinitializes the image to an empty (black) image with the given dimensions.

clear_read_size(): Undoes the effect of a previous call to set_read_size().

copy_channel(copy: PNMImage, src_channel: int, dest_channel: int): Copies a channel from one image into another. Images must be the same size

copy_channel(copy: PNMImage, xto: int, yto: int, cto: int, xfrom: int, yfrom: int, cfrom: int, x_size: int, y_size: int): Copies just a single channel from the source image into a single channel of this image, leaving the remaining channels alone.

copy_channel_bits(copy: PNMImage, src_channel: int, dest_channel: int, src_mask: int, right_shift: int)

Copies some subset of the bits of the specified channel from one image into some subset of the bits of the specified channel in another image. Images must be the same size.

If right_shift is negative, it means a left shift.

copy_from(copy: PNMImage): Makes this image become a copy of the other image.

copy_header_from(header: PNMImageHeader): Copies just the header information into this image. This will blow away any image data stored in the image. The new image data will be allocated, but left unitialized.

copy_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int): Copies a rectangular area of another image into a rectangular area of this image. Both images must already have been initialized. The upper-left corner of the region in both images is specified, and the size of the area; if the size is omitted, it defaults to the entire other image, or the largest piece that will fit.

darken_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int, pixel_scale: float)

Behaves like copy_sub_image(), but the resulting color will be the darker of the source and destination colors at each pixel (and at each R, G, B, A component value).

If pixel_scale is not 1.0, it specifies an amount to scale each pixel value of the source image before applying it to the target image. The scale is applied with the center at 1.0: scaling the pixel value smaller brings it closer to 1.0.

do_fill_distance(xi: int, yi: int, d: int): Recursively fills in the minimum distance measured from a certain set of points into the gray channel.

expand_border(left: int, right: int, bottom: int, top: int, color: LColorf)

Expands the image by the indicated number of pixels on each edge. The new pixels are set to the indicated color.

If any of the values is negative, this actually crops the image.

fill(gray: float): Sets the entire image (except the alpha channel) to the given grayscale level.

fill(red: float, green: float, blue: float): Sets the entire image (except the alpha channel) to the given color.

fill_distance_inside(mask: PNMImage, threshold: float, radius: int, shrink_from_border: bool)

Replaces this image with a grayscale image whose gray channel represents the linear Manhattan distance from the nearest dark pixel in the given mask image, up to the specified radius value (which also becomes the new maxval). radius may range from 0 to maxmaxval; smaller values will compute faster. A dark pixel is defined as one whose pixel value is < threshold.

If shrink_from_border is true, then the mask image is considered to be surrounded by a border of dark pixels; otherwise, the border isn’t considered.

This can be used, in conjunction with threshold, to shrink a mask image inwards by a certain number of pixels.

The mask image may be the same image as this one, in which case it is destructively modified by this process.

fill_distance_outside(mask: PNMImage, threshold: float, radius: int)

Replaces this image with a grayscale image whose gray channel represents the linear Manhattan distance from the nearest white pixel in the given mask image, up to the specified radius value (which also becomes the new maxval). radius may range from 0 to maxmaxval; smaller values will compute faster. A white pixel is defined as one whose pixel value is >= threshold.

This can be used, in conjunction with threshold, to grow a mask image outwards by a certain number of pixels.

The mask image may be the same image as this one, in which case it is destructively modified by this process.

fill_val(gray: int): Sets the entire image (except the alpha channel) to the given grayscale level.

fill_val(red: int, green: int, blue: int): Sets the entire image (except the alpha channel) to the given color.

flip(flip_x: bool, flip_y: bool, transpose: bool): Reverses, transposes, and/or rotates the image in-place according to the specified parameters. If flip_x is true, the x axis is reversed; if flip_y is true, the y axis is reversed. Then, if transpose is true, the x and y axes are exchanged. These parameters can be used to select any combination of 90-degree or 180-degree rotations and flips.

from_alpha_val(input_value: int) → float: A handy function to scale alpha values from [0..get_maxval()] to [0..1].

from_val(input_value: xel) → LRGBColorf: A handy function to scale non-alpha values from [0..get_maxval()] to [0..1]. Do not use this for alpha values, see from_alpha_val().

from_val(input_value: int) → float: A handy function to scale non-alpha values from [0..get_maxval()] to [0..1]. Do not use this for alpha values, see from_alpha_val().

gamma_correct(from_gamma: float, to_gamma: float): Assuming the image was constructed with a gamma curve of from_gamma in the RGB channels, converts it to an image with a gamma curve of to_gamma in the RGB channels. Does not affect the alpha channel.

gamma_correct_alpha(from_gamma: float, to_gamma: float): Assuming the image was constructed with a gamma curve of from_gamma in the alpha channel, converts it to an image with a gamma curve of to_gamma in the alpha channel. Does not affect the RGB channels.

gaussian_filter(radius: float): This flavor of gaussian_filter() will apply the filter over the entire image without resizing or copying; the effect is that of a blur operation.

gaussian_filter_from(radius: float, copy: PNMImage): Makes a resized copy of the indicated image into this one using the indicated filter. The image to be copied is squashed and stretched to match the dimensions of the current image, applying the appropriate filter to perform the stretching.

get_alpha(x: int, y: int) → float: Returns the alpha component color at the indicated pixel. It is an error to call this unless has_alpha() is true. The value returned is a float in the range 0..1.

get_alpha_val(x: int, y: int) → int: Returns the alpha component color at the indicated pixel. It is an error to call this unless has_alpha() is true. The value returned is in the range 0..maxval and always linear.

get_average_gray() → float: Returns the average grayscale component of all of the pixels in the image.

get_average_xel() → LRGBColorf: Returns the average color of all of the pixels in the image.

get_average_xel_a() → LColorf: Returns the average color of all of the pixels in the image, including the alpha channel.

get_blue(x: int, y: int) → float: Returns the blue component color at the indicated pixel. The value returned is a linearized float in the range 0..1.

get_blue_val(x: int, y: int) → int: Returns the blue component color at the indicated pixel. The value returned is in the range 0..maxval and encoded in the configured color space.

get_bright(x: int, y: int) → float: Returns the linear brightness of the given xel, as a linearized float in the range 0..1. This flavor of get_bright() returns the correct grayscale brightness level for both full-color and grayscale images.

get_bright(x: int, y: int, rc: float, gc: float, bc: float) → float: This flavor of get_bright() works correctly only for color images. It returns a single brightness value for the RGB color at the indicated pixel, based on the supplied weights for each component.

get_bright(x: int, y: int, rc: float, gc: float, bc: float, ac: float) → float: This flavor of get_bright() works correctly only for four-channel images. It returns a single brightness value for the RGBA color at the indicated pixel, based on the supplied weights for each component.

get_channel(x: int, y: int, channel: int) → float: Returns the nth component color at the indicated pixel. The channel index should be in the range 0..(get_num_channels()-1). The channels are ordered B, G, R, A. This is slightly less optimal than accessing the component values directly by named methods. The value returned is a float in the range 0..1.

get_channel_val(x: int, y: int, channel: int) → int: Returns the nth component color at the indicated pixel. The channel index should be in the range 0..(get_num_channels()-1). The channels are ordered B, G, R, A. This is slightly less optimal than accessing the component values directly by named methods. The value returned is in the range 0..maxval.

get_color_space() → ColorSpace: Returns the color space in which the image is encoded.

get_gray(x: int, y: int) → float: Returns the gray component color at the indicated pixel. This only has a meaningful value for grayscale images; for other image types, this returns the value of the blue channel only. However, also see the get_bright() function. The value returned is a linearized float in the range 0..1.

get_gray_val(x: int, y: int) → int: Returns the gray component color at the indicated pixel. This only has a meaningful value for grayscale images; for other image types, this returns the value of the blue channel only. However, also see the get_bright() function. The value returned is in the range 0..maxval and encoded in the configured color space.

get_green(x: int, y: int) → float: Returns the green component color at the indicated pixel. The value returned is a linearized float in the range 0..1.

get_green_val(x: int, y: int) → int: Returns the green component color at the indicated pixel. The value returned is in the range 0..maxval and encoded in the configured color space.

get_pixel(x: int, y: int) → PixelSpec: Returns the (r, g, b, a) pixel value at the indicated pixel, using a PixelSpec object.

get_read_x_size() → int: Returns the requested x_size of the image if set_read_size() has been called, or the image x_size otherwise (if it is known).

get_read_y_size() → int: Returns the requested y_size of the image if set_read_size() has been called, or the image y_size otherwise (if it is known).

get_red(x: int, y: int) → float: Returns the red component color at the indicated pixel. The value returned is a linearized float in the range 0..1.

get_red_val(x: int, y: int) → int: Returns the red component color at the indicated pixel. The value returned is in the range 0..maxval and encoded in the configured color space.

get_xel(x: int, y: int) → LRGBColorf: Returns the RGB color at the indicated pixel. Each component is a linearized float in the range 0..1.

get_xel_a(x: int, y: int) → LColorf: Returns the RGBA color at the indicated pixel. Each component is a linearized float in the range 0..1.

get_xel_val(x: int, y: int) → xel: Returns the RGB color at the indicated pixel. Each component is in the range 0..maxval.

get_xel_val(x: int, y: int) → xel: Returns the RGB color at the indicated pixel. Each component is in the range 0..maxval.

has_read_size() → bool: Returns true if set_read_size() has been called.

indirect_1d_lookup(index_image: PNMImage, channel: int, pixel_values: PNMImage)

index_image is a WxH grayscale image, while pixel_values is an Nx1 color (or grayscale) image. Typically pixel_values will be a 256x1 image.

Fills the PNMImage with a new image the same width and height as index_image, with the same number of channels as pixel_values.

Each pixel of the new image is computed with the formula:

new_image(x, y) = pixel_values(index_image(x, y)[channel], 0)

At present, no interpolation is performed; the nearest value in pixel_values is discovered. This may change in the future.

is_valid() → bool: Returns true if the image has been read in or correctly initialized with a height and width. If this returns false, virtually all member functions except clear() and read() are invalid function calls.

lighten_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int, pixel_scale: float)

Behaves like copy_sub_image(), but the resulting color will be the lighter of the source and destination colors at each pixel (and at each R, G, B, A component value).

If pixel_scale is not 1.0, it specifies an amount to scale each pixel value of the source image before applying it to the target image.

make_grayscale(): Converts the image from RGB to grayscale. Any alpha channel, if present, is left undisturbed.

make_grayscale(rc: float, gc: float, bc: float): Converts the image from RGB to grayscale. Any alpha channel, if present, is left undisturbed. The optional rc, gc, bc values represent the relative weights to apply to each channel to convert it to grayscale.

make_histogram(hist: Histogram): Computes a histogram of the colors used in the image.

make_rgb(): Converts the image from grayscale to RGB. Any alpha channel, if present, is left undisturbed.

mult_sub_image(copy: PNMImage, xto: int, yto: int, xfrom: int, yfrom: int, x_size: int, y_size: int, pixel_scale: float): Behaves like copy_sub_image(), except the copy pixels are multiplied to the pixels of the destination, after scaling by the specified pixel_scale. Unlike blend_sub_image(), the alpha channel is not treated specially.

operator__() → PNMImage

perlin_noise_fill(perlin: StackedPerlinNoise2): Variant of perlin_noise_fill that uses an existing StackedPerlinNoise2 object.

perlin_noise_fill(sx: float, sy: float, table_size: int, seed: int, ox: float, oy: float): Fills the image with a grayscale perlin noise pattern based on the indicated parameters. Uses set_xel() to set the grayscale values. The sx and sy parameters are in multiples of the size of this image. See also the PerlinNoise2 class in mathutil.

premultiply_alpha()

Converts an image in-place to its “premultiplied” form, where, for every pixel in the image, the red, green, and blue components are multiplied by that pixel’s alpha value.

This does not modify any alpha values.

quantize(max_colors: int)

Reduces the number of unique colors in the image to (at most) the given count. Fewer colors than requested may be left in the image after this operation, but never more.

At present, this is only supported on images without an alpha channel.

New in version 1.10.5.

quick_filter_from(copy: PNMImage, xborder: int, yborder: int): Resizes from the given image, with a fixed radius of 0.5. This is a very specialized and simple algorithm that doesn’t handle dropping below the Nyquist rate very well, but is quite a bit faster than the more general box_filter(), above. If borders are specified, they will further restrict the size of the resulting image. There’s no point in using quick_box_filter() on a single image.

read(filename: Filename, type: PNMFileType, report_unknown_type: bool) → bool: Reads the indicated image filename. If type is non-NULL, it is a suggestion for the type of file it is. Returns true if successful, false on error.

read(reader: PNMReader) → bool

This flavor of read() uses an already-existing PNMReader to read the image file. You can get a reader via the PNMImageHeader.make_reader() methods. This is a good way to examine the header of a file (for instance, to determine its size) before actually reading the entire image.

The PNMReader is always deleted upon completion, whether successful or not.

read(data: istream, filename: str, type: PNMFileType, report_unknown_type: bool) → bool

Reads the image data from the indicated stream.

The filename is advisory only, and may be used to suggest a type if it has a known extension.

If type is non-NULL, it is a suggestion for the type of file it is (and a non-NULL type will override any magic number test or filename extension lookup).

Returns true if successful, false on error.

remix_channels(conv: LMatrix4): Transforms every pixel using the operation (Ro,Go,Bo) = conv.xform_point(Ri,Gi,Bi); Input must be a color image.

remove_alpha(): Removes the image’s alpha channel, if it exists.

render_spot(fg: LColorf, bg: LColorf, min_radius: float, max_radius: float)

Renders a solid-color circle, with a fuzzy edge, into the center of the PNMImage. If the PNMImage is non-square, this actually renders an ellipse.

The min_radius and max_radius are in the scale 0..1, where 1.0 means the full width of the image. If min_radius == max_radius, the edge is sharp (but still antialiased); otherwise, the pixels between min_radius and max_radius are smoothly blended between fg and bg colors.

rescale(min_val: float, max_val: float): Rescales the RGB channel values so that any values in the original image between min_val and max_val are expanded to the range 0 .. 1. Values below min_val are set to 0, and values above max_val are set to 1. Does not affect the alpha channel, if any.

reverse_rows(): Performs an in-place reversal of the row (y) data.

set_alpha(x: int, y: int, a: float): Sets the alpha component color only at the indicated pixel. It is an error to call this unless has_alpha() is true. The value given should be in the range 0..1.

set_alpha_val(x: int, y: int, a: int)

Sets the alpha component color only at the indicated pixel. It is an error to call this unless has_alpha() is true. The value given should be in the range 0..maxval.

This value is always linearly encoded, even if the image is set to the sRGB color space.

set_blue(x: int, y: int, b: float): Sets the blue component color only at the indicated pixel. The value given should be a linearized float in the range 0..1.

set_blue_val(x: int, y: int, b: int): Sets the blue component color only at the indicated pixel. The value given should be in the range 0..maxval, encoded in the configured color space. See set_blue() if you instead have a linearized and normalized floating-point value.

set_channel(x: int, y: int, channel: int, value: float): Sets the nth component color at the indicated pixel. The channel index should be in the range 0..(get_num_channels()-1). The channels are ordered B, G, R, A. This is slightly less optimal than setting the component values directly by named methods. The value given should be a float in the range 0..1.

set_channel_val(x: int, y: int, channel: int, value: int): Sets the nth component color at the indicated pixel. The channel index should be in the range 0..(get_num_channels()-1). The channels are ordered B, G, R, A. This is slightly less optimal than setting the component values directly by named methods. The value given should be in the range 0..maxval.

set_color_space(color_space: ColorSpace)

Converts the colors in the image to the indicated color space. This may be a lossy operation, in particular when going from sRGB to linear. The alpha channel remains untouched.

Note that, because functions like get_xel() and set_xel() work on linearized floating-point values, this conversion won’t affect those values (aside from some minor discrepancies due to storage precision). It does affect the values used by get_xel_val() and set_xel_val(), though, since those operate on encoded colors.

Some color spaces, particularly scRGB, may enforce the use of a particular maxval setting.

set_color_type(color_type: ColorType): Translates the image to or from grayscale, color, or four-color mode. Grayscale images are converted to full-color images with R, G, B set to the original gray level; color images are converted to grayscale according to the value of Bright(). The alpha channel, if added, is initialized to zero.

set_gray(x: int, y: int, gray: float): Sets the gray component color at the indicated pixel. This is only meaningful for grayscale images; for other image types, this simply sets the blue component color. However, also see set_xel(), which can set all the component colors to the same grayscale level, and hence works correctly both for grayscale and color images. The value given should be a linearized float in the range 0..1.

set_gray_val(x: int, y: int, gray: int): Sets the gray component color at the indicated pixel. This is only meaningful for grayscale images; for other image types, this simply sets the blue component color. However, also see set_xel_val(), which can set all the component colors to the same grayscale level, and hence works correctly both for grayscale and color images. The value given should be in the range 0..maxval, encoded in the configured color space. See set_gray() if you instead have a linearized normalized floating-point value.

set_green(x: int, y: int, g: float): Sets the green component color only at the indicated pixel. The value given should be a linearized float in the range 0..1.

set_green_val(x: int, y: int, g: int): Sets the green component color only at the indicated pixel. The value given should be in the range 0..maxval, encoded in the configured color space. See set_green() if you instead have a linearized and normalized floating-point value.

set_maxval(maxval: int): Rescales the image to the indicated maxval.

set_num_channels(num_channels: int): Changes the number of channels associated with the image. The new number of channels must be an integer in the range 1 through 4, inclusive. This will allocate and/or deallocate memory as necessary to accommodate; see set_color_type().

set_pixel(x: int, y: int, pixel: PixelSpec): Sets the (r, g, b, a) pixel value at the indicated pixel, using a PixelSpec object.

set_read_size(x_size: int, y_size: int)

Specifies the size to we’d like to scale the image upon reading it. This will affect the next call to read(). This is usually used to reduce the image size, e.g. for a thumbnail.

If the file type reader supports it (e.g. JPEG), then this will scale the image during the read operation, consequently reducing memory and CPU utilization. If the file type reader does not support it, this will load the image normally, and them perform a linear scale after it has been loaded.

set_red(x: int, y: int, r: float): Sets the red component color only at the indicated pixel. The value given should be a linearized float in the range 0..1.

set_red_val(x: int, y: int, r: int): Sets the red component color only at the indicated pixel. The value given should be in the range 0..maxval, encoded in the configured color space. See set_red() if you instead have a linearized and normalized floating-point value.

set_xel(x: int, y: int, value: LRGBColorf): Changes the RGB color at the indicated pixel. Each component is a linearized float in the range 0..1.

set_xel(x: int, y: int, gray: float): Changes all three color components at the indicated pixel to the same value. The value is a linearized float in the range 0..1.

set_xel(x: int, y: int, r: float, g: float, b: float): Changes the RGB color at the indicated pixel. Each component is a linearized float in the range 0..1.

set_xel_a(x: int, y: int, value: LColorf): Changes the RGBA color at the indicated pixel. Each component is a linearized float in the range 0..1.

set_xel_a(x: int, y: int, r: float, g: float, b: float, a: float): Changes the RGBA color at the indicated pixel. Each component is a linearized float in the range 0..1.

set_xel_val(x: int, y: int, value: xel): Changes the RGB color at the indicated pixel. Each component is in the range 0..maxval, encoded in the configured color space. See set_xel() if you instead have a linearized and normalized floating-point value.

set_xel_val(x: int, y: int, gray: int): Changes all three color components at the indicated pixel to the same value. The value is in the range component is in the range 0..maxval, encoded in the configured color space. See set_xel() if you instead have a linearized and normalized floating-point value.

set_xel_val(x: int, y: int, r: int, g: int, b: int): Changes the RGB color at the indicated pixel. Each component is in the range 0..maxval, encoded in the configured color space. See set_xel() if you instead have a linearized and normalized floating-point value.

take_from(orig: PNMImage): Move the contents of the other image into this one, and empty the other image.

threshold(select_image: PNMImage, channel: int, threshold: float, lt: PNMImage, ge: PNMImage)

Selectively copies each pixel from either one source or another source, depending on the pixel value of the indicated channel of select_image.

For each pixel (x, y):

s = select_image.get_channel(x, y, channel). Set this image’s (x, y) to:

lt.get_xel(x, y) if s < threshold, or

ge.get_xel(x, y) if s >= threshold

Any of select_image, lt, or ge may be the same PNMImge object as this image, or the same as each other; or they may all be different. All images must be the same size. As a special case, lt and ge may both be 1x1 images instead of the source image size.

to_alpha_val(input_value: float) → int: A handy function to scale alpha values from [0..1] to [0..get_maxval()].

to_val(input_value: LRGBColorf) → xel: A handy function to scale non-alpha values from [0..1] to [0..get_maxval()]. Do not use this for alpha values, see to_alpha_val().

to_val(input_value: float) → int: A handy function to scale non-alpha values from [0..1] to [0..get_maxval()]. Do not use this for alpha values, see to_alpha_val().

unfiltered_stretch_from(copy: PNMImage): Resizes from the indicated image into this one by performing a nearest- point sample.

unpremultiply_alpha()

Converts an image in-place to its “straight alpha” form (presumably from a “premultiplied” form), where, for every pixel in the image, the red, green, and blue components are divided by that pixel’s alpha value.

This does not modify any alpha values.

write(filename: Filename, type: PNMFileType) → bool: Writes the image to the indicated filename. If type is non-NULL, it is a suggestion for the type of image file to write.

write(writer: PNMWriter) → bool

This flavor of write() uses an already-existing PNMWriter to write the image file. You can get a writer via the PNMImageHeader.make_writer() methods.

The PNMWriter is always deleted upon completion, whether successful or not.

write(data: ostream, filename: str, type: PNMFileType) → bool

Writes the image to the indicated ostream.

The filename is advisory only, and may be used suggest a type if it has a known extension.

If type is non-NULL, it is a suggestion for the type of image file to write.