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What program is best at JPEG compression?
Are some graphics programs better than others for compressing JPEG?
A friend swears that Image Ready is the best for getting the smallest file with same quality. But I see a few companies have made utilities purely for compressing pictures, and claim they obtain better compression than the top tier graphics programs. I presume there are different numerical routines used by different companies in their software, but I would guess maybe 5% variation in file size at best. I know there was a comparison done several years ago, but the website with the pictures seems to be kaput. (www.imagecompress.com ?) Is there a recent comparison of different programs to see who offers the best compression? That is, best quality for same size, or smallest size for same quality. |
#2
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What program is best at JPEG compression?
wrote in message
oups.com... Are some graphics programs better than others for compressing JPEG? A friend swears that Image Ready is the best for getting the smallest file with same quality. But I see a few companies have made utilities purely for compressing pictures, and claim they obtain better compression than the top tier graphics programs. I presume there are different numerical routines used by different companies in their software, but I would guess maybe 5% variation in file size at best. I know there was a comparison done several years ago, but the website with the pictures seems to be kaput. (www.imagecompress.com ?) Is there a recent comparison of different programs to see who offers the best compression? That is, best quality for same size, or smallest size for same quality. Jpeg compression is a big subject, since JPEG is a lossy compression scheme, there are always trade offs. File size vs. amount of compression and artifacts. The better Graphic programs give you a choice of the amount of compression used. The de facto best Photo editor it Adobe Photoshop. The full version is about $650 or $150 for the upgrade. Photoshop Elements is a consumer grade Photo editor that costs much less money ($100) and does most of what Photoshop CS does. http://www.adobe.com/products/photoshopelwin/ -- CSM1 http://www.carlmcmillan.com -- |
#3
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What program is best at JPEG compression?
On Thu, 19 Jul 2007 09:57:39 -0500, "CSM1"
wrote: wrote in message roups.com... Are some graphics programs better than others for compressing JPEG? A friend swears that Image Ready is the best for getting the smallest file with same quality. But I see a few companies have made utilities purely for compressing pictures, and claim they obtain better compression than the top tier graphics programs. I presume there are different numerical routines used by different companies in their software, but I would guess maybe 5% variation in file size at best. I know there was a comparison done several years ago, but the website with the pictures seems to be kaput. (www.imagecompress.com ?) Is there a recent comparison of different programs to see who offers the best compression? That is, best quality for same size, or smallest size for same quality. Jpeg compression is a big subject, since JPEG is a lossy compression scheme, there are always trade offs. File size vs. amount of compression and artifacts. The better Graphic programs give you a choice of the amount of compression used. The de facto best Photo editor it Adobe Photoshop. The full version is about $650 or $150 for the upgrade. Photoshop Elements is a consumer grade Photo editor that costs much less money ($100) and does most of what Photoshop CS does. http://www.adobe.com/products/photoshopelwin/ I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? |
#4
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What program is best at JPEG compression?
imbsysop wrote:
[] I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? There is a standard, but with a large number of different choices. For example, you can change the colour resolution relative to the luminance resolution. How different programmers interpret "95% quality" is up to them, so it's entirely possible that different programs will better suit different images. Cheers, David |
#5
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What program is best at JPEG compression?
David J Taylor wrote:
imbsysop wrote: [] I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? There is a standard, but with a large number of different choices. For example, you can change the colour resolution relative to the luminance resolution. How different programmers interpret "95% quality" is up to them, so it's entirely possible that different programs will better suit different images. Ultimately, I think that's the key: "different programs will better suit DIFFERENT IMAGES". There is no one "best" or "worst" implementation because how "well" a particular encoding scheme works will depend on the specific image it's dealing with. |
#6
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What program is best at JPEG compression?
Matt wrote on Tue, 24 Jul 2007 14:46:19 GMT:
MI David J Taylor wrote: ?? imbsysop wrote: ?? [] I've always thought jpeg and its compression algorithm ?? were subject to ?? a general standard and not to any program makers' fantasy ?? ..???? ?? ?? There is a standard, but with a large number of different ?? choices. For example, you can change the colour ?? resolution relative to the luminance resolution. How ?? different programmers interpret "95% quality" is up to ?? them, so it's entirely possible that different programs ?? will better suit different images. It is an interesting question as to which is the best general method since *most* people won't want to use more than one technique. It does beg the question of what is wanted. Is the "best" method that which produces the smallest result or some sort of compromise among size, resolution and color resolution etc.? James Silverton Potomac, Maryland E-mail, with obvious alterations: not.jim.silverton.at.verizon.not |
#7
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What program is best at JPEG compression?
"imbsysop" wrote in message ... I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? As with MPEG, JPEG decoders are deterministic (given the same input, they all produce the same output), but the encoders are not. Choices can be made during encoding even for algorithms that produce the same output file size. MPEG encoding has even more variance and there can be enormous quality differences in the decoded output of a given average bit rate. Coders for DVDs do a good job because the encoding does not have to be done in real time and multipass encoding and larger GOP sizes are used. David |
#8
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What program is best at JPEG compression?
On Jul 23, 1:47 pm, "David" wrote:
"imbsysop" wrote in message ... I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? The standard has a large number of free parameters in it. And although many applications use a scaled version of the original canonical quantisation table given in the standard other encoders have made different choices. And in some cases an encoder with all the time in the world can find an optimised quantisation table for a specific target image. This helps encode physically small dimensioned images in a more compact JPEG file. As with MPEG, JPEG decoders are deterministic (given the same input, they all produce the same output), but the encoders are not. Choices can be made during encoding even for algorithms that produce the same output file size. Sadly even though the specification of JPEG is fairly precise there is still enough latitude for the decoder that there is plenty of scope for different decoders producing different images from the same JPEG encoded file. The most commonly noticeable implementation differences are in the chroma subsampling treatment (seriously broken in PSPro 9's encoder). And where for example the IJG codec uses interpolation whereas Adobe uses pixel replication - both of these methods have their merits and demerits. There are other options dating from the bad old days when computing a DCT was still hard work that permit various speed for accuracy trade- offs (much less of an issue these days with fast hardware floating point support). Regards, Martin Brown |
#9
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What program is best at JPEG compression?
"imbsysop" wrote in message
... On Thu, 19 Jul 2007 09:57:39 -0500, "CSM1" wrote: wrote in message groups.com... Are some graphics programs better than others for compressing JPEG? A friend swears that Image Ready is the best for getting the smallest file with same quality. But I see a few companies have made utilities purely for compressing pictures, and claim they obtain better compression than the top tier graphics programs. I presume there are different numerical routines used by different companies in their software, but I would guess maybe 5% variation in file size at best. I know there was a comparison done several years ago, but the website with the pictures seems to be kaput. (www.imagecompress.com ?) Is there a recent comparison of different programs to see who offers the best compression? That is, best quality for same size, or smallest size for same quality. Jpeg compression is a big subject, since JPEG is a lossy compression scheme, there are always trade offs. File size vs. amount of compression and artifacts. The better Graphic programs give you a choice of the amount of compression used. The de facto best Photo editor it Adobe Photoshop. The full version is about $650 or $150 for the upgrade. Photoshop Elements is a consumer grade Photo editor that costs much less money ($100) and does most of what Photoshop CS does. http://www.adobe.com/products/photoshopelwin/ I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? Have you read the JPEG specification? http://www.w3.org/Graphics/JPEG/jfif3.pdf If you are talking about Digital cameras, you use the EXIF 2.2 spec. http://www.exif.org/Exif2-2.PDF There is a lot of room for interpolation of the application of JPEG compression. Many factors that have to be balanced for the best result. Since Jpeg is lossy, it throws away a lot of important information that is gone forever, if you choose wrong. -- CSM1 http://www.carlmcmillan.com -- |
#10
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What program is best at JPEG compression?
On Mon, 23 Jul 2007 14:40:31 GMT, "CSM1"
wrote: "imbsysop" wrote in message .. . On Thu, 19 Jul 2007 09:57:39 -0500, "CSM1" wrote: wrote in message egroups.com... Are some graphics programs better than others for compressing JPEG? A friend swears that Image Ready is the best for getting the smallest file with same quality. But I see a few companies have made utilities purely for compressing pictures, and claim they obtain better compression than the top tier graphics programs. I presume there are different numerical routines used by different companies in their software, but I would guess maybe 5% variation in file size at best. I know there was a comparison done several years ago, but the website with the pictures seems to be kaput. (www.imagecompress.com ?) Is there a recent comparison of different programs to see who offers the best compression? That is, best quality for same size, or smallest size for same quality. Jpeg compression is a big subject, since JPEG is a lossy compression scheme, there are always trade offs. File size vs. amount of compression and artifacts. The better Graphic programs give you a choice of the amount of compression used. The de facto best Photo editor it Adobe Photoshop. The full version is about $650 or $150 for the upgrade. Photoshop Elements is a consumer grade Photo editor that costs much less money ($100) and does most of what Photoshop CS does. http://www.adobe.com/products/photoshopelwin/ I've always thought jpeg and its compression algorithm were subject to a general standard and not to any program makers' fantasy ..???? Have you read the JPEG specification? http://www.w3.org/Graphics/JPEG/jfif3.pdf yes I did but did you ? quote "... JPEG Compression Although any JPEG process is supported by the syntax of the JPEG File Interchange Format (JFIF) it is strongly recommended that the JPEG baseline process be used for the purposes of file interchange. This ensures maximum compatibility with all applications supporting JPEG. JFIF conforms to the JPEG Draft International Standard (ISO DIS 10918-1). The JPEG File Interchange Format is entirely compatible with the standard JPEG interchange format; the only additional requirement is the mandatory presence of the APP0 marker right after the SOI marker. Note that JPEG interchange format requires (as does JFIF) that all table specifications used in the encoding process be coded in the bitstream prior to their use...." unquote |
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