* This option will enable lossless cropping. See #tjTransform() for more * information. */ #define TJXOPT_CROP 4 /** * This option will discard the color data in the input image and produce * a grayscale output image. */ #define TJXOPT_GRAY 8 /** * This option will p...
jpeg_enable_lossless(&this->cinfo, this->losslessPSV, this->losslessPt); #endif if (pixelFormat == TJPF_GRAY) this->subsamp = TJSAMP_GRAY; else if (this->subsamp != TJSAMP_GRAY) this->subsamp = TJSAMP_444; return; } jpeg_set_quality(&this->cinfo, this->quality,...
有损压缩时-e 9反而可能生成更大的文件,最高-e 10,比-e 9文件小,比-e 7大。 @echooffsetinDir=D:\testsetoutDir=D:\outsetquality=90setjpeglossless=1seteffort=7mkdir"%outDir%"XCOPY /T"%inDir%""%outDir%"setlocalenabledelayedexpansionfor/r"%inDir%"%%iin(*.png,*.jpg)do(set"dirnoname=...
flip transforms, lossless crop is restricted by the current JPEG format: the upper left corner of the selected region must fall on an iMCU boundary. If this does not hold for the given crop parameters, we silently move the upper left corner up and/or left to make it so, simultaneously in...
JPEG XL supports lossy compression and lossless compression of ultra-high-resolution images (up to 1 terapixel), up to 32 bits per component, up to 4099 components (including alpha transparency), animated images" Not bad. Count me in. Why have I never heard of it? Votes 2 Upvotes Translat...
INTRO: IMAGE COMPRESSION An important concept which distinguishes many image types is whether they are compressed. Compressed files are significantly smaller than their uncompressed counterparts, and fall into two general categories: "lossy" and "lossless." Lossless compression ensures that all image info...
which would not be true if you useddjpegfollowed bycjpegto accomplish the same conversion. But by the same token,jpegtrancannot perform lossy operations such as changing the image quality. However, while the image data is losslessly transformed, metadata can be removed. See the-copyoption for...
If you want to keep the original files intact, enable the Create backup image before rotation option in the JPEG Lossless Rotator's Options menu. Alternatively, you can manually make a copy of the files before the rotation.Is the rotation by JPEG Lossless Rotator really lossless?
The desired visual fidelity can be selected using the--distanceparameter (in units of just-noticeable difference, where 0 is lossless and the most useful lossy range is 0.5 .. 3.0), or using--quality(on a scale from 0 to 100, roughly matching libjpeg). Theencode effortcan be selected usi...
IG_COMPRESSION_JPEG (Lossless): Grayscale: 8, 16 bpp; RGB: 24 bpp; IG_COMPRESSION_JPEG (Progressive JPEG): Grayscale: 8, 12 bpp; RGB: 24, 36 bpp RGBA saving is disabled by default. Set SAVE_ALLOW_RGBA control parameter to TRUE to enable it. ...