原文連結： https://www.cnblogs.com/DjangoBlog/p/3557744.html Image 模組 Image 模組提供了同名的類用來表示PIL的影象。Image模組還提供了許多工廠（factory）函式，包塊從檔案載入影象的函式，以及建立新影象的函式。    例子  下面的指令碼載入了一個影象，並把它旋轉了45度，然後呼叫外部的檢視器（通常在Unix下是xv，Windows下是paint）。    開啟，旋轉，和顯示影象(使用預設的檢視器)   

from PIL import Image 
im = Image.open("bride.jpg") 
im.rotate(45).show() 
 

下面的指令碼為當前目錄下所以的JPEG影象建立漂亮128x128的縮圖。   建立縮圖   

from PIL import Image 
import glob, os 
 
size = 128, 128 
 
for infile in glob.glob("*.jpg"): 
    file, ext = os.path.splitext(infile) 
    im = Image.open(infile) 
    im.thumbnail(size, Image.ANTIALIAS) 
    im.save(file + ".thumbnail", "JPEG") 
 

函式  new 

Image.new(mode, size) => image 

Image.new(mode, size, color) => image 

  以指定的模式和大小建立一個新影象。大小以2元元組的形式給出。給colour賦單個值，表示要建立單波段影象，元組表示建立多波段影象（每個波段一個值）。如果忽略colour引數，影象將以黑色填充。如果colour設為None，影象不會被初始化。   

open 

Image.open(infile) => image 

Image.open(infile, mode) => image 

開啟並識別給定影象檔案。這是一個偷懶的操作；真正的影象資料只有到處理的時候才會被讀入（呼叫load函式強制載入）。如果給出了模式（mode）引數，它必須設為“r”。    要開啟影象，即可以使用字串（表示檔名）也可以使用檔案物件。對後一種情況，檔案物件必須實現了read，seek，和 tell 方法，並以二進位制模式開啟。 

blend 

Image.blend(image1, image2, alpha) => image 

 通過使用alpha常量，在影象進行差值操作，建立新影象。兩個影象必須具有相同的大小和模式。   out = image1 * (1.0 - alpha) + image2 * alpha  （注：沒有成功）  如果設定alpha為0.0，將返回第一個影象的拷貝。如果設定alpha為1.0，將返回第二個影象的拷貝。對alpha的值沒有限制。必要的話，結果會被剪裁，以適合允許的輸出範圍。 

 composite 

Image.composite(image1, image2, mask) => image 

 使用遮罩（mask）作為alpha，通過在兩個影象之間進行插值來建立一個新影象。遮罩影象的模式可以是“1”，“L”，或者“RGBA”。所有的影象的大小必須有相同。 

 eval 

Image.eval_r(image, function) => image 

 把函式（function）（應該接收一個引數）應用到所給影象的每一個畫素。如果影象有多個波段，相同的函式會應用到每一個波段。注意，該函式對每一個可能的畫素值只計算一次，所有不能使用隨機元件（components）或者其它發生器（generators）。 

 frombuffer 

Image.frombuffer(mode, size, data) => image 

 (PIL1.1.4新增)。使用標準的“raw”解碼器，把來自字串或者緩衝區（buffer）物件的影象資料建立為一個影象記憶體（image memory）。對於某些模式，影象記憶體會和原來的緩衝區共享記憶體（這意味著對原始緩衝區物件的修改會影響影象）。不是所有的模式都能共享記憶體；支援共享記憶體的模式包括：“L”，“RGBX”，“RGBA”和“CMYK”。對其其它模式，這個函式的作用與fromstring函式類似。    注意：1.1.6版中，預設的方向與fromstring的不同。這些可能會在未來的版本中發生變化，所以為了最大的相容性，建議在使用“raw”解碼器的時候給出所有的引數。    im = Image.frombuffer(mode, size, data, "raw", mode, 0, 1)Image.frombuffer(mode, size, data, decoder, parameters) => image    與呼叫fromstring 相同。 

 fromstring 

Image.fromstring(mode, size, data) => image 

 使用標準的“raw”解碼器從來自字串的畫素資料建立一個影象記憶體。    Image.fromstring(mode, size, data, decoder, parameters) => image    也一樣，但是允許你使用PIL支援的任何畫素解碼器。關於可用解碼器的更多資訊，參見Writing Your Own File Decoder節    注意，這個函式只對畫素資料解碼，而不是整個影象。如果字串中包含了一個完整的影象檔案，可以使用StringIO物件對它進行處理，並使用open函式載入影象。 

 merge 

Image.merge(mode, bands) => image 

 從幾個單波段影象建立一個新影象。bands引數是包含影象的元組或列表，一個影象對應模式中描述的一個波段。所有波段的影象必須有相同的大小。    方法  一個Image類的例項具有下列方法。除非另外指出，所有的方法都返回一個新的Image類的例項，包含處理過的影象資料。 

 convert 

im.convert(mode) => image 

返回影象轉換後的副本    如果原始影象是調色盤影象，這個函式通過調色盤轉換畫素。忽略mode引數，會自動選擇一個模式，以保證所有的影象資訊和調色盤資訊在沒有調色盤的時候也能表示出來。    從彩色影象轉換到黑白影象時，影象庫使用ITU-R 601-2 luma轉換：        L = R * 299/1000 + G * 587/1000 + B * 114/1000在把影象轉換為二值圖（bilevel image）（模式“1”）時，源影象首先被轉換為黑白圖。然後在結果中，值大於127的畫素點被設定為白色，影象抖動（and the image is dithered）。使用point方法可以改變閾值。    im.convert(mode, matrix) => image    使用轉換矩陣，把一個 "RGB" 影象轉換為 "L" 或者 "RGB" 影象。其中矩陣是一個4元或16元元組。    下面的例子把一個RGB影象轉換(根據ITU-R 709進行線性校正，using the D65 luminant)到CIE XYZ顏色空間：   

Convert RGB to XYZ 
     rgb2xyz = ( 
        0.412453, 0.357580, 0.180423, 0, 
        0.212671, 0.715160, 0.072169, 0, 
        0.019334, 0.119193, 0.950227, 0 ) 
    out = im.convert("RGB", rgb2xyz)

copy 

im.copy() => image 

 Copies the image. Use this method if you wish to paste things into an image, but still retain the original.複製影象。如果你想往影象上貼上東西，但是又保持源影象不變可以使用這個函式。  

crop 

im.crop(box) => image 

返回當前影象的一個矩形區域。box引數是一個定義了左，上，右，下畫素座標的4元元組。    這是一個投籃操作。改變源影象可能會也可能不會影響剪裁的影象。要得到一個單獨的拷貝，可以在剪裁的副本上應用load函式。 

 draft 

im.draft(mode, size)  

配置影象檔案載入器，使它返回一個與給定模式和大小盡可能匹配的影象。比如，你可以在載入的時候，把一個彩色的JPEG影象轉換為一個灰度圖，或者從一個PCD檔案中提取出一個128x192的版本。    注意這個方法在適當的時候修改影象物件。如果影象已經載入了，這個方法可能無效。 

 filter 

im.filter(filter) => image 

Returns a copy of an image filtered by the given filter. For a list of available filters, see the ImageFilter module.   

fromstring 

im.fromstring(data)  

im.fromstring(data, decoder, parameters)   Same as the fromstring function, but loads data into the current image.  

getbands 

im.getbands() => tuple of strings  

Returns a tuple containing the name of each band. For example, getbands on an RGB image returns ("R", "G", "B"). 

 getbbox 

im.getbbox() => 4-tuple or None    Calculates the bounding box of the non-zero regions in the image. The bounding box is returned as a 4-tuple defining the left, upper, right, and lower pixel coordinate. If the image is completely empty, this method returns None. 

 getcolors 

im.getcolors() => a list of (count, color) tuples or None  im.getcolors(maxcolors) => a list of (count, color) tuples or None    (New in 1.1.5) Returns an unsorted list of (count, color) tuples, where the count is the number of times the corresponding color occurs in the image.    If the maxcolors value is exceeded, the method stops counting and returns None. The default maxcolors value is 256. To make sure you get all colors in an image, you can pass in size[0]*size[1] (but make sure you have lots of memory before you do that on huge images). 

 getdata 

im.getdata() => sequence    Returns the contents of an image as a sequence object containing pixel values. The sequence object is flattened, so that values for line one follow directly after the values of line zero, and so on.    Note that the sequence object returned by this method is an internal PIL data type, which only supports certain sequence operations, including iteration and basic sequence access. To convert it to an ordinary sequence (e.g. for printing), use list(im.getdata()).  

getextrema 

im.getextrema() => 2-tuple    Returns a 2-tuple containing the minimum and maximum values of the image. In the current version of PIL, this is only applicable to single-band images.  

getpixel 

im.getpixel(xy) => value or tuple    Returns the pixel at the given position. If the image is a multi-layer image, this method returns a tuple.    Note that this method is rather slow; if you need to process larger parts of an image from Python, you can either use pixel access objects (see load), or the getdata method.  

histogram 

im.histogram() => list    Returns a histogram for the image. The histogram is returned as a list of pixel counts, one for each pixel value in the source image. If the image has more than one band, the histograms for all bands are concatenated (for example, the histogram for an "RGB" image contains 768 values).    A bilevel image (mode "1") is treated as a greyscale ("L") image by this method.    im.histogram(mask) => list    Returns a histogram for those parts of the image where the mask image is non-zero. The mask image must have the same size as the image, and be either a bi-level image (mode "1") or a greyscale image ("L"). 

load 

im.load()    Allocates storage for the image and loads it from the file (or from the source, for lazy operations). In normal cases, you don't need to call this method, since the Image class automatically loads an opened image when it is accessed for the first time.    (New in 1.1.6) In 1.1.6 and later, load returns a pixel access object that can be used to read and modify pixels. The access object behaves like a 2-dimensional array, so you can do:    pix = im.load()  print pix[x, y]  pix[x, y] = value  Access via this object is a lot faster than getpixel and putpixel.  

offset 

im.offset(xoffset, yoffset) => image    (Deprecated) Returns a copy of the image where the data has been offset by the given distances. Data wraps around the edges. If yoffset is omitted, it is assumed to be equal to xoffset.    This method is deprecated. New code should use the offset function in the ImageChops module.  

paste 

im.paste(image, box)    Pastes another image into this image. The box argument is either a 2-tuple giving the upper left corner, a 4-tuple defining the left, upper, right, and lower pixel coordinate, or None (same as (0, 0)). If a 4-tuple is given, the size of the pasted image must match the size of the region.    If the modes don't match, the pasted image is converted to the mode of this image (see the convert method for details).    im.paste(colour, box)    Same as above, but fills the region with a single colour. The colour is given as a single numerical value for single-band images, and a tuple for multi-band images.    im.paste(image, box, mask)    Same as above, but updates only the regions indicated by the mask. You can use either "1", "L" or "RGBA" images (in the latter case, the alpha band is used as mask). Where the mask is 255, the given image is copied as is. Where the mask is 0, the current value is preserved. Intermediate values can be used for transparency effects.    Note that if you paste an "RGBA" image, the alpha band is ignored. You can work around this by using the same image as both source image and mask.    im.paste(colour, box, mask)    Same as above, but fills the region indicated by the mask with a single colour.  

point 

im.point(table) => image    im.point(function) => image    Returns a copy of the image where each pixel has been mapped through the given table. The table should contains 256 values per band in the image. If a function is used instead, it should take a single argument. The function is called once for each possible pixel value, and the resulting table is applied to all bands of the image.    If the image has mode "I" (integer) or "F" (floating point), you must use a function, and it must have the following format:        argument * scale + offsetExample:        out = im.point(lambda i: i * 1.2 + 10)You can leave out either the scale or the offset.    im.point(table, mode) => image    im.point(function, mode) => image    Map the image through table, and convert it on fly. This can be used to convert "L" and "P" images to "1" in one step, e.g. to threshold an image.    (New in 1.1.5) This form can also be used to convert "L" images to "I" or "F", and to convert "I" images with 16-bit data to "L". In the last case, you must use a 65536-item lookup table.  

putalpha 

im.putalpha(band)    Copies the given band to the alpha layer of the current image.    The image must be an "RGBA" image, and the band must be either "L" or "1".    (New in PIL 1.1.5) You can use putalpha on other modes as well; the image is converted in place, to a mode that matches the current mode but has an alpha layer (this usually means "LA" or "RGBA"). Also, the band argument can be either an image, or a colour value (an integer).  

putdata 

im.putdata(data)    im.putdata(data, scale, offset)    Copy pixel values from a sequence object into the image, starting at the upper left corner (0, 0). The scale and offset values are used to adjust the sequence values:        pixel = value * scale + offsetIf the scale is omitted, it defaults to 1.0. If the offset is omitted, it defaults to 0.0. 

putpalette 

im.putpalette(sequence)    Attach a palette to a "P" or "L" image. The palette sequence should contain 768 integer values, where each group of three values represent the red, green, and blue values for the corresponding pixel index. Instead of an integer sequence, you can use an 8-bit string. 

putpixel 

im.putpixel(xy, colour)    Modifies the pixel at the given position. The colour is given as a single numerical value for single-band images, and a tuple for multi-band images.    Note that this method is relatively slow. If you're using 1.1.6, pixel access objects (see load) provide a faster way to modify the image. If you want to generate an entire image, it can be more efficient to create a Python list and use putdata to copy it to the image. For more extensive changes, use paste or the ImageDraw module instead.    You can speed putpixel up a bit by "inlining" the call to the internal putpixel implementation method:        im.load()      putpixel = im.im.putpixel      for i in range(n):         ...         putpixel((x, y), value)  In 1.1.6, the above is better written as:        pix = im.load()      for i in range(n):          ...          pix[x, y] = value    resize  im.resize(size) => image    im.resize(size, filter) => image    Returns a resized copy of an image. The size argument gives the requested size in pixels, as a 2-tuple: (width, height).    The filter argument can be one of NEAREST (use nearest neighbour), BILINEAR (linear interpolation in a 2x2 environment), BICUBIC (cubic spline interpolation in a 4x4 environment), or ANTIALIAS (a high-quality downsampling filter). If omitted, or if the image has mode "1" or "P", it is set to NEAREST. 

 rotate 

im.rotate(angle) => image    im.rotate(angle, filter=NEAREST, expand=0) => image    Returns a copy of an image rotated the given number of degrees counter clockwise around its centre.    The filter argument can be one of NEAREST (use nearest neighbour), BILINEAR (linear interpolation in a 2x2 environment), or BICUBIC (cubic spline interpolation in a 4x4 environment). If omitted, or if the image has mode "1" or "P", it is set to NEAREST.    The expand argument, if true, indicates that the output image should be made large enough to hold the rotated image. If omitted or false, the output image has the same size as the input image. 

 save 

im.save(outfile, options...)    im.save(outfile, format, options...)    Saves the image under the given filename. If format is omitted, the format is determined from the filename extension, if possible. This method returns None.    Keyword options can be used to provide additional instructions to the writer. If a writer doesn't recognise an option, it is silently ignored. The available options are described later in this handbook.    You can use a file object instead of a filename. In this case, you must always specify the format. The file object must implement the seek, tell, and write methods, and be opened in binary mode.    If the save fails, for some reason, the method will raise an exception (usually an IOError exception). If this happens, the method may have created the file, and may have written data to it. It's up to your application to remove incomplete files, if necessary. 

 seek 

im.seek(frame)    Seeks to the given frame in a sequence file. If you seek beyond the end of the sequence, the method raises an EOFError exception. When a sequence file is opened, the library automatically seeks to frame 0.    Note that in the current version of the library, most sequence formats only allows you to seek to the next frame. 

 show 

im.show()    Displays an image. This method is mainly intended for debugging purposes.    On Unix platforms, this method saves the image to a temporary PPM file, and calls the xv utility.    On Windows, it saves the image to a temporary BMP file, and uses the standard BMP display utility to show it.    This method returns None.  

split 

im.split() => sequence    Returns a tuple of individual image bands from an image. For example, splitting an "RGB" image creates three new images each containing a copy of one of the original bands (red, green, blue). 

 tell 

im.tell() => integer  Returns the current frame number.  

thumbnail 

im.thumbnail(size)   im.thumbnail(size, filter)    Modifies the image to contain a thumbnail version of itself, no larger than the given size. This method calculates an appropriate thumbnail size to preserve the aspect of the image, calls the draft method to configure the file reader (where applicable), and finally resizes the image.    The filter argument can be one of NEAREST, BILINEAR, BICUBIC, or ANTIALIAS (best quality). If omitted, it defaults to NEAREST.    Note that the bilinear and bicubic filters in the current version of PIL are not well-suited for thumbnail generation. You should use ANTIALIAS unless speed is much more important than quality.    Also note that this function modifies the Image object in place. If you need to use the full resolution image as well, apply this method to a copy of the original image. This method returns None.  

tobitmap 

im.tobitmap() => string    Returns the image converted to an X11 bitmap.  

tostring 

im.tostring() => string   Returns a string containing pixel data, using the standard "raw" encoder.   im.tostring(encoder, parameters) => string   Returns a string containing pixel data, using the given data encoding.  

transform 

im.transform(size, method, data) => image   im.transform(size, method, data, filter) => image    Creates a new image with the given size, and the same mode as the original, and copies data to the new image using the given transform.    In the current version of PIL, the method argument can be EXTENT (cut out a rectangular subregion), AFFINE (affine transform), QUAD (map a quadrilateral to a rectangle), or MESH (map a number of source quadrilaterals in one operation). The various methods are described below.    The filter argument defines how to filter pixels from the source image. In the current version, it can be NEAREST (use nearest neighbour), BILINEAR (linear interpolation in a 2x2 environment), or BICUBIC (cubic spline interpolation in a 4x4 environment). If omitted, or if the image has mode "1" or "P", it is set to NEAREST.    im.transform(size, EXTENT, data) => image    im.transform(size, EXTENT, data, filter) => image    Extracts a subregion from the image.    Data is a 4-tuple (x0, y0, x1, y1) which specifies two points in the input image's coordinate system. The resulting image will contain data sampled from between these two points, such that (x0, y0) in the input image will end up at (0,0) in the output image, and (x1, y1) at size.    This method can be used to crop, stretch, shrink, or mirror an arbitrary rectangle in the current image. It is slightly slower than crop, but about as fast as a corresponding resize operation.    im.transform(size, AFFINE, data) => image    im.transform(size, AFFINE, data, filter) => image    Applies an affine transform to the image, and places the result in a new image with the given size.    Data is a 6-tuple (a, b, c, d, e, f) which contain the first two rows from an affine transform matrix. For each pixel (x, y) in the output image, the new value is taken from a position (a x + b y + c, d x + e y + f) in the input image, rounded to nearest pixel.    This function can be used to scale, translate, rotate, and shear the original image.    im.transform(size, QUAD, data) => image    im.transform(size, QUAD, data, filter) => image    Maps a quadrilateral (a region defined by four corners) from the image to a rectangle with the given size.    Data is an 8-tuple (x0, y0, x1, y1, x2, y2, y3, y3) which contain the upper left, lower left, lower right, and upper right corner of the source quadrilateral.    im.transform(size, MESH, data) image => image    im.transform(size, MESH, data, filter) image => image    Similar to QUAD, but data is a list of target rectangles and corresponding source quadrilaterals. 

 transpose 

im.transpose(method) => image    Returns a flipped or rotated copy of an image.    Method can be one of the following: FLIP_LEFT_RIGHT, FLIP_TOP_BOTTOM, ROTATE_90, ROTATE_180, or ROTATE_270.  

verify 

im.verify()    Attempts to determine if the file is broken, without actually decoding the image data. If this method finds any problems, it raises suitable exceptions. This method only works on a newly opened image; if the image has already been loaded, the result is undefined. Also, if you need to load the image after using this method, you must reopen the image file.   

Attributes 

Instances of the Image class have the following attributes:  

format 

im.format => string or None    The file format of the source file. For images created by the library, this attribute is set to None.  

mode 

im.mode => string    Image mode. This is a string specifying the pixel format used by the image. Typical values are "1", "L", "RGB", or "CMYK."  

size 

im.size => (width, height)    Image size, in pixels. The size is given as a 2-tuple (width, height).  

palette 

im.palette => palette