ImageOptionsBase 类
内容
[
隐藏
]Summary: The image base options.
Module: aspose.imaging
Full Name: aspose.imaging.ImageOptionsBase
Inheritance: IMetadataContainer, IHasExifData, IHasMetadata, IHasXmpData, DisposableObject
Properties
| Name | Type | Access | 描述 |
|---|---|---|---|
| buffer_size_hint | int | r/w | 获取或设置缓冲区大小提示，该提示定义了所有内部缓冲区的最大允许大小。 |
| disposed | bool | r | 获取一个值，指示此实例是否已释放。 |
| exif_data | ExifData | r/w | 获取或设置 Exif 数据。 |
| full_frame | bool | r/w | 获取或设置一个值，指示是否为 [full frame]。 |
| keep_metadata | bool | r/w | 获取一个值，指示在导出时是否保留原始图像元数据。 |
| multi_page_options | MultiPageOptions | r/w | 多页选项 |
| palette | IColorPalette | r/w | 获取或设置颜色调色板。 |
| resolution_settings | ResolutionSetting | r/w | 获取或设置分辨率设置。 |
| source | Source | r/w | 获取或设置用于创建图像的源。 |
| vector_rasterization_options | VectorRasterizationOptions | r/w | 获取或设置矢量光栅化选项。 |
| xmp_data | XmpPacketWrapper | r/w | 获取或设置 XMP 元数据容器。 |
Methods
| Name | 描述 |
|---|---|
| clone() | 创建此实例的成员逐个克隆。 |
| try_set_metadata(metadata) | 尝试设置一个 metadata 实例，前提是此 Image 实例支持并实现 IImageMetadataFormat 实例。 |
Property: buffer_size_hint
获取或设置缓冲区大小提示，该提示定义了所有内部缓冲区的最大允许大小。
See also:
Example # 1: The following example shows how to set a memory limit when creating a new JPE…
Property: palette
获取或设置颜色调色板。
See also:
Example # 1: The following example shows how to set a palette to a BMP image to reduce its…
Example # 2: The following example shows how to compress a PNG image, using indexed color …
Example # 3: The following example loads a BMP image and saves it back to BMP using variou…
Property: resolution_settings
获取或设置分辨率设置。
See also:
Example # 1: The following example loads a BMP image and saves it back to BMP using variou…
Example # 2: The following example creates a palettized grayscale BMP image and then saves…
Method: clone()
clone()
创建此实例的成员逐个克隆。
Returns
| Type | Description |
|---|---|
| ImageOptionsBase | 此实例的成员逐个克隆。 |
Method: try_set_metadata(metadata)
try_set_metadata(metadata)
尝试设置一个 metadata 实例，前提是此 Image 实例支持并实现 IImageMetadataFormat 实例。
Parameters:
| 参数 | Type | Description |
|---|---|---|
| metadata | IImageMetadataFormat | 元数据。 |
Returns
| Type | Description |
|---|---|
| bool | 如果 IMetadataContainer 实例支持和/或实现 IImageMetadataFormat 实例，则为 true；否则为 false。 |
Examples
The following example shows how to set a palette to a BMP image to reduce its output size.
from aspose.pycore import as_of
from aspose.imaging import Point, Color, Graphics, ColorPaletteHelper
from aspose.imaging.brushes import LinearGradientBrush
from aspose.imaging.fileformats.bmp import BmpImage
from aspose.imaging.imageoptions import BmpOptions
from os.path import join as path_join
# 创建一个 100 x 100 像素的 BMP 图像。
with BmpImage(100, 100) as bmpImage:
# 图像左上角到右下角的线性渐变。
brush = LinearGradientBrush(Point(0, 0), Point(bmpImage.width, bmpImage.height),
Color.red,
Color.green)
# 使用线性渐变画刷填充整个图像。
gr = Graphics(bmpImage)
gr.fill_rectangle(brush, bmpImage.bounds)
# 获取最接近的 8 位颜色调色板，覆盖尽可能多的像素，以便调色板图像
# 在视觉上几乎与没有调色板的 bmp 无法区分
palette = ColorPaletteHelper.get_close_image_palette(bmpImage, 256)
# 8 位调色板最多包含 256 种颜色。
saveOptions = BmpOptions()
saveOptions.palette = palette
saveOptions.bits_per_pixel = 8
with stream_ext.create_memory_stream() as stream:
bmpImage.save(stream, saveOptions)
print(f"The size of image with palette is {stream.tell()} bytes.")
stream.seek(0)
bmpImage.save(stream)
print(f"The size of image without palette is {stream.tell()} bytes.")
# 输出如下：
# 带调色板的图像大小为 11078 字节。
# 不带调色板的图像大小为 40054 字节。
The following example shows how to compress a PNG image, using indexed color with best fit palette
from aspose.pycore import as_of
from aspose.imaging import Image, ColorPaletteHelper, RasterImage, PaletteMiningMethod
from aspose.imaging.fileformats.png import PngColorType
# 加载 png 图像
sourceFilePath = "OriginalRings.png"
outputFilePath = "OriginalRingsOutput.png"
with Image.load(sourceFilePath) as image:
png_options = PngOptions()
png_options.progressive = True
# 使用索引颜色类型
png_options.color_type = PngColorType.INDEXED_COLOR
# 使用最大压缩
png_options.compression_level = 9
# 获取最接近的 8 位颜色调色板，覆盖尽可能多的像素，以便图像
# 带调色板的图像在视觉上几乎与没有调色板的图像无法区分。
png_options.palette = ColorPaletteHelper.get_close_image_palette(
as_of(image, RasterImage), 256,
PaletteMiningMethod.HISTOGRAM)
image.save(outputFilePath, png_options);
}
# 输出文件大小应显著减小
The following example loads a BMP image and saves it back to BMP using various save options.
from aspose.imaging import Image, RasterImage, ColorPaletteHelper, ResolutionSetting
from aspose.imaging.imageoptions import BmpOptions
from aspose.imaging.fileformats.bmp import BitmapCompression
import os
import aspose.pycore as aspycore
directory = "c:\\temp\\"
with Image.load(os.path.join(directory, "sample.bmp")) as image:
rasterImage = aspycore.as_of(image, RasterImage)
# 创建 BmpOptions
saveOptions = BmpOptions()
# 使用每像素 8 位来减小输出图像的大小。
saveOptions.bits_per_pixel = 8
# 设置最接近的 8 位颜色调色板，覆盖最多的图像像素，以便调色板图像
# 几乎在视觉上与非调色板图像无异。
saveOptions.palette = ColorPaletteHelper.get_close_image_palette(rasterImage, 256)
# 保存时不使用压缩。
# 您也可以使用 RLE-8 压缩来减小输出图像的大小。
saveOptions.compression = BitmapCompression.RGB
# 将水平和垂直分辨率设置为 96 dpi。
saveOptions.resolution_settings = ResolutionSetting(96.0, 96.0)
image.save(os.path.join(directory, "sample.bmpoptions.bmp"), saveOptions)
The following example creates a palettized grayscale BMP image and then saves it to a file.
from os.path import join as path_join
from aspose.imaging import Image, ColorPaletteHelper, ResolutionSetting, Graphics, Point, Color
from aspose.imaging.sources import FileCreateSource
from aspose.imaging.imageoptions import BmpOptions
from aspose.imaging.fileformats.bmp import BitmapCompression
from aspose.imaging.brushes import LinearGradientBrush
directory = "c:\\temp\\"
createOptions = BmpOptions()
# 保存到文件
createOptions.source = FileCreateSource(path_join(directory, "output.palette8bit.bmp"), False)
# 使用每像素 8 位来减小输出图像的大小。
createOptions.bits_per_pixel = 8
# 设置标准的 8 位灰度颜色调色板，覆盖所有灰度颜色。
# 如果处理后的图像仅包含灰度颜色，则其调色板化版本
# 在视觉上与非调色板图像无异。
createOptions.palette = ColorPaletteHelper.create_8_bit_grayscale(False)
# 保存时不使用压缩。
# 您也可以使用 RLE-8 压缩来减小输出图像的大小。
createOptions.compression = BitmapCompression.RGB
# 将水平和垂直分辨率设置为 96 dpi。
createOptions.resolution_settings = ResolutionSetting(96.0, 96.0)
# 创建一个 100 x 100 像素的 BMP 图像并保存到文件。
with Image.create(createOptions, 100, 100) as image:
graphics = Graphics(image)
gradientBrush = LinearGradientBrush(Point(0, 0), Point(image.width, image.height), Color.black, Color.white)
# 用灰度渐变填充图像
graphics.fill_rectangle(gradientBrush, image.bounds)
image.save()
The following example shows how to set a memory limit when creating a new JPEG image. The memory limit is the maximum allowed size (in megabytes) for all internal buffers.
from os.path import join
from aspose.imaging import Image
from aspose.imaging.sources import FileCreateSource
from aspose.imaging.imageoptions import JpegOptions
from aspose.imaging.fileformats.jpeg import JpegCompressionMode
dir_: str = "c:\\aspose.imaging\\issues\\net\\3404\\"
# 为目标创建的图像设置 50 兆字节的内存限制
create_options = JpegOptions()
create_options.compression_type = JpegCompressionMode.PROGRESSIVE
create_options.buffer_size_hint = 50
create_options.source = FileCreateSource(join(dir_, "createdFile.jpg"), False)
with Aspose.Imaging.Image.create(create_options, 1000, 1000) as image:
# 保存到相同位置
image.save()
