Declaration
property BitsPerSample: integer;
Description
Specifies the depth, in bits, for each sample (channel).
Allowed values:
| Value | Description |
| 1 | 1 bit black & white |
| 2 to 7 | Color mapped bitmap (from 4 to 128 colors) |
| 8 | Color mapped (256 colors), 8 bit gray scale, 24 bit RGB, 48 bit CMYK, 24 bit CIELab |
| 16 | 16 bit gray scale or 48 bit RGB |
| 32 | 32 bit floating point |
Default: 8
Note:
◼ Setting BitsPerSample only updates the meta-data. Use a method like
ConvertTo to reduce the color palette of the image.
◼ If
AutoSetBitDepth is enabled, then setting
PixelFormat will automatically update
SamplesPerPixel and BitsPerSample
◼ If you are using a
TIEMultiBitmap or
TImageEnMView, you can use
DuplicateCompressionInfo to propogate the parameter to all frames
BitsPerSample and SamplesPerPixel
SamplesPerPixel specifies the number of channels within an image, for example a gray-scale image has 1 channel, whereas a full color (RGB) image typically has three three channels, or four for some formats containing alpha transparency.
BitsPerSample specifies the amount of depth within each sample. A gray-scale with 256 levels of gray has SamplesPerPixel=1 and BitsPerSample=8 (2^8 = 256), whereas a monochrome image has SamplesPerPixel=1 and BitsPerSample=1. A full color JPEG has SamplesPerPixel=3 and BitsPerSample=8. Indexed/mapped color formats, such as GIF, will have one channel (SamplesPerPixel=1).
Bits per Pixel =
SamplesPerPixel *
BitsPerSample.
See Also
◼ ConvertTo◼ SamplesPerPixel◼ PixelFormat◼ JPEG_ColorSpace◼ J2000_ColorSpace◼ TIFF_PhotometInterpret◼ TIFF_JPEGColorSpace◼ AutoSetBitDepthExample
// Save 256 color mapped bitmap
ImageEnView1.IO.Params.BitsPerSample := 8;
ImageEnView1.IO.Params.SamplesPerPixel := 1;
ImageEnView1.IO.SaveToFile('D:\Alfa.bmp');
// Load a full-color image and save it as 256 color one
ImageEnView1.IO.LoadFromFile('D:\Im.jpg');
ImageEnView1.Proc.ConvertTo(ie8p, ieptFixedHalftone256, iedtOrdered8x8);
ImageEnView1.IO.Params.BitsPerSample := 8;
ImageEnView1.IO.Params.SamplesPerPixel := 1;
ImageEnView1.IO.SaveToFile('D:\Image256.bmp');
// Save 32bit gray-scale TIFF (ie32f)
// Note: Compression must be: ioTIFF_UNCOMPRESSED, ioTIFF_LZW, ioTIFF_PACKBITS or ioTIFF_ZIP
ImageEnView1.LegacyBitmap := false;
ImageEnView1.IEBitmap.PixelFormat := ie32f;
ImageEnView1.IO.Params.BitsPerSample := 32;
ImageEnView1.IO.Params.SamplesPerPixel := 1;
ImageEnView1.IO.Params.TIFF_PhotometInterpret := ioTIFF_BLACKISZERO;
ImageEnView1.IO.Params.TIFF_Compression := ioTIFF_UNCOMPRESSED;
ImageEnView1.IO.SaveToFileTIFF('D:\GrayTiff32.tiff');
// Save a monochrome TIFF image
ImageEnView1.IO.Params.BitsPerSample := 1;
ImageEnView1.IO.Params.SamplesPerPixel := 1;
ImageEnView1.IO.Params.TIFF_Compression := ioTIFF_G4FAX;
ImageEnView1.IO.SaveToFile('D:\output.tif');