WSQ and not JPEG is used by AFIS/IAFIS to store digitized fingerprints, does it matter?
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
JPEG v. WSQ Digitized Fingerprints
-
Steve Everist
- Site Admin
- Posts: 551
- Joined: Sun Jul 03, 2005 4:27 pm
- Location: Bellevue, WA
Michael,
Those images you posted were a joke. You didn't even know what you were doing when you sized them. They were deceptive either on purpose or by ignorance by you and Larry.
JPG images are compressed (lossy). Once saved, they will be the same upon opening and closing. Only when resaving the image is there another compression of the pixel data. I'm assuming that it is the same for the WSQ images.
For you to take a picture of unknown quantity (original resolution information was not provided), resample it way down, do whatever else to the image, save it on a website as an obviously blurry image, then say that it is representative of a digital image used for forenic purposes is ridiculous.
When asked for a complete history of that image, you were unable to provide it. Yet you presented it a bunch of people who would have been required to do that with their images. The software program you used was even questionable for what you were doing or trying to show. Most of the audience of this forum uses Photoshop alone, or combined with More Hits software which allows "complete disclosure" of what is done to an image. Why can't you do what you would ask of us?
You have yet to present anything credible in this forum regarding digital images.
Those images you posted were a joke. You didn't even know what you were doing when you sized them. They were deceptive either on purpose or by ignorance by you and Larry.
JPG images are compressed (lossy). Once saved, they will be the same upon opening and closing. Only when resaving the image is there another compression of the pixel data. I'm assuming that it is the same for the WSQ images.
For you to take a picture of unknown quantity (original resolution information was not provided), resample it way down, do whatever else to the image, save it on a website as an obviously blurry image, then say that it is representative of a digital image used for forenic purposes is ridiculous.
When asked for a complete history of that image, you were unable to provide it. Yet you presented it a bunch of people who would have been required to do that with their images. The software program you used was even questionable for what you were doing or trying to show. Most of the audience of this forum uses Photoshop alone, or combined with More Hits software which allows "complete disclosure" of what is done to an image. Why can't you do what you would ask of us?
You have yet to present anything credible in this forum regarding digital images.
Steve E.
-
Guest
Michael
Those images you posted were a joke. You didn't even know what you were doing when you sized them. They were deceptive either on purpose or by ignorance by you and Larry.
~Steve E.
Steve
Anyone with some college algebra would realize that the aspect ratio (legnth x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed as equal in size.
I will hold another class in approximately one year.
Michael Cherry
Those images you posted were a joke. You didn't even know what you were doing when you sized them. They were deceptive either on purpose or by ignorance by you and Larry.
~Steve E.
Steve
Anyone with some college algebra would realize that the aspect ratio (legnth x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed as equal in size.
I will hold another class in approximately one year.
Michael Cherry
-
Steve Everist
- Site Admin
- Posts: 551
- Joined: Sun Jul 03, 2005 4:27 pm
- Location: Bellevue, WA
What does any of this have to do with video?Anonymous wrote:
Steve
Anyone with some college algebra would realize that the aspect ratio (legnth x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed as equal in size.
I will hold another class in approximately one year.
Michael Cherry
I requested information at the time that you were either unwilling or unable to produce regarding the complete history of those images.
Anyone who works with digital on a casual basis could tell that there was an intentional manipulation on your part to present a story you wanted told, regardless of the truth.
Now you come in here making a claim with no supporting information beyond "Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image..." At the time you couldn't explain the history of those images, and here we are a year later with a reference to images that can't be seen today and were questionable, at best, yesterday.
See you in a year, but don't expect a very large classroom.
Steve E.
-
Michael Cherry
Steve,
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
Michael Cherry
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
Michael Cherry
-
sandra wiese
- Posts: 88
- Joined: Wed Jul 06, 2005 5:47 pm
- Location: Colorado
I must just be stupid
"Anyone with some college algebra would realize that the aspect ratio (legnth x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed as equal in size. "
Excuse what you will likely presume to be my stupidity (it has been almost 20 years since my last algebra class--and a cold day in hell before I care to take another, thank you), but this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day. YOU get to choose the aspect ratio and the paper size or, in your case, the size of the area you are posting the images on your webite. So you can't make the "pictures" you took both be 2" by 2" and still accurate, THEN CHANGE THE SIZE OF THE PICTURE. To use "aspect ratio" as an excuse for the very poor pictures you previously posted is, well, pretty silly.
Excuse what you will likely presume to be my stupidity (it has been almost 20 years since my last algebra class--and a cold day in hell before I care to take another, thank you), but this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day. YOU get to choose the aspect ratio and the paper size or, in your case, the size of the area you are posting the images on your webite. So you can't make the "pictures" you took both be 2" by 2" and still accurate, THEN CHANGE THE SIZE OF THE PICTURE. To use "aspect ratio" as an excuse for the very poor pictures you previously posted is, well, pretty silly.
-
Michael Cherry
1. WSQ and not JPEG is used by AFIS/IAFIS to store digitized fingerprints, does it matter?
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
Computer software cannot accurtely change the laws of physics.
Michael Cherry
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
Computer software cannot accurtely change the laws of physics.
Michael Cherry
-
Charles Parker
- Posts: 586
- Joined: Mon Jul 04, 2005 6:15 am
- Location: Cedar Creek, TX
"Computer software cannot accurtely change the laws of physics."
Michael Cherry
Mr. Cherry, I think you should also mention that silver based film cannot change the laws of physics.
Since they both cannot change the laws of physics, I am at a loss to understand your post.
When I saw the photographs last year they were out of focus.
WSQ, JPEG, and 35mm out of focus images all have one thing in common. They are out of focus. What I saw did not represent any change in the size ratio, but merely a rendition of some poor photography.
Provide those with the experience and who asked for your information the details of your presentation so they can see what was done to make the photographs you presented so out of focus.
Most of the people that monitor this site see silver based film and digital images on a daily basis. I have seen besides the 5X7, 4X5, 120, and 35mm films in my career, also images from WSQ, PSD, TIFF, JPEG, BMP, and so forth. Some are good and some are not. But none of them in 33 years have presented out of focus photos like you did unless some one took them out of focus.
When you present information that a 100 or so individuals have not experienced in their day to day work, and tell them it is wrong, you are pressing on the wrong theme.
If a 1,000 people are telling you that it is not bad luck to drive a red car, why are you still preaching that it is bad luck to drive a red car. Perhaps it is time to reevaluate your theme, or maybe present it in such a manner that is acceptable, understandable, and verifible.
I think your photographs were out of focus. Please provide me with some proof that I am wrong and that the photographs were in focus and what I was seeing was just a difference in image size.
Respectfully, waiting for proof.
Michael Cherry
Mr. Cherry, I think you should also mention that silver based film cannot change the laws of physics.
Since they both cannot change the laws of physics, I am at a loss to understand your post.
When I saw the photographs last year they were out of focus.
WSQ, JPEG, and 35mm out of focus images all have one thing in common. They are out of focus. What I saw did not represent any change in the size ratio, but merely a rendition of some poor photography.
Provide those with the experience and who asked for your information the details of your presentation so they can see what was done to make the photographs you presented so out of focus.
Most of the people that monitor this site see silver based film and digital images on a daily basis. I have seen besides the 5X7, 4X5, 120, and 35mm films in my career, also images from WSQ, PSD, TIFF, JPEG, BMP, and so forth. Some are good and some are not. But none of them in 33 years have presented out of focus photos like you did unless some one took them out of focus.
When you present information that a 100 or so individuals have not experienced in their day to day work, and tell them it is wrong, you are pressing on the wrong theme.
If a 1,000 people are telling you that it is not bad luck to drive a red car, why are you still preaching that it is bad luck to drive a red car. Perhaps it is time to reevaluate your theme, or maybe present it in such a manner that is acceptable, understandable, and verifible.
I think your photographs were out of focus. Please provide me with some proof that I am wrong and that the photographs were in focus and what I was seeing was just a difference in image size.
Respectfully, waiting for proof.
Knuckle Draggin Country Cousin
Cedar Creek, TX
Cedar Creek, TX
-
Guest
1. WSQ and not JPEG is used by AFIS/IAFIS to store digitized fingerprints, does it matter?
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
Michael Cherry
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
Michael Cherry
-
George Reis
- Posts: 147
- Joined: Wed Jul 27, 2005 1:00 pm
- Location: Orange County, CA - USA
- Contact:
Well, there are a few issues here, and each one shows a misunderstanding of some basic concepts by Mr. Cherry. The three issues involve 1) compression issues with JPEG and WSQ; 2) the image aspect ratio of different media; and 3) pixel aspect ratio of video.
As to the first issue regarding WSQ and JPEG artifacts. Any of us can apply very severe lossy compression to an image and cause it to become degraded. But, this would not be a condemnation of that compression algorithm - it would only be a condemnation of that level of compression on that image (and possibly that type of image). Other types of images at different bit depths, in different color spaces, of different subject matter would be affected differently by the same compression. And, different amounts of compression will have different results. Mr. Cherry's misrepresentation with the images of the watch were of the wrong subject matter, the wrong color space, the wrong sizing at the wrong level of compression.
Mr. Cherry states that the aspect ratio of different formats are different. This may or may not be true, as there are so many different camera models and CCD and CMOS chips now that some are square, some are the same as 35mm, some are the same as 4:3 video, and some are different than any of these. But, he then claims that this makes it impossible for the same subject to be represented as the same size, which is simply silly. If I have an entire print within the frame of any two cameras, regardless of whether they are digital, film or video, they can be all made the same size and include the entire print. If I want my image frames to also be the same size, then I would need to crop some of the images. Nothing complex here, but I think Mr. Cherry is confusing this with the pixel aspect ratio of analog video - which is the third point.
Analog video uses non-square rectangular pixels. Because of this, when video is digitized there is distortion caused by the conversion of the non-square pixels into square pixels. This is well known in the forensic video anlaysis field and is corrected for in the images are going to be used as still images. For instance, a video captured at 720 X 486 may be corrected by converting it to 648 X 486 pixels. By doing so, even video can be made to the same sizing and include the same information as film or digital photos or scans.
None of this is rocket science, and I think the first two issues are common sense. The third issue is one that any of us who have worked with analog video, or read about it would know.
What becomes more of a point is whether the level of bandwidth spent to correct Mr. Cherry virtually every time he posts is worth it. When I read his posts, I don't think he is attempting to learn anything new, I don't believe he works in our field, but instead he shows a complete misunderstanding of imaging concepts and tries to prove some obscure point with that misunderstanding. I'm not sure that this merits the level of discussion that we provide him with.
George
As to the first issue regarding WSQ and JPEG artifacts. Any of us can apply very severe lossy compression to an image and cause it to become degraded. But, this would not be a condemnation of that compression algorithm - it would only be a condemnation of that level of compression on that image (and possibly that type of image). Other types of images at different bit depths, in different color spaces, of different subject matter would be affected differently by the same compression. And, different amounts of compression will have different results. Mr. Cherry's misrepresentation with the images of the watch were of the wrong subject matter, the wrong color space, the wrong sizing at the wrong level of compression.
Mr. Cherry states that the aspect ratio of different formats are different. This may or may not be true, as there are so many different camera models and CCD and CMOS chips now that some are square, some are the same as 35mm, some are the same as 4:3 video, and some are different than any of these. But, he then claims that this makes it impossible for the same subject to be represented as the same size, which is simply silly. If I have an entire print within the frame of any two cameras, regardless of whether they are digital, film or video, they can be all made the same size and include the entire print. If I want my image frames to also be the same size, then I would need to crop some of the images. Nothing complex here, but I think Mr. Cherry is confusing this with the pixel aspect ratio of analog video - which is the third point.
Analog video uses non-square rectangular pixels. Because of this, when video is digitized there is distortion caused by the conversion of the non-square pixels into square pixels. This is well known in the forensic video anlaysis field and is corrected for in the images are going to be used as still images. For instance, a video captured at 720 X 486 may be corrected by converting it to 648 X 486 pixels. By doing so, even video can be made to the same sizing and include the same information as film or digital photos or scans.
None of this is rocket science, and I think the first two issues are common sense. The third issue is one that any of us who have worked with analog video, or read about it would know.
What becomes more of a point is whether the level of bandwidth spent to correct Mr. Cherry virtually every time he posts is worth it. When I read his posts, I don't think he is attempting to learn anything new, I don't believe he works in our field, but instead he shows a complete misunderstanding of imaging concepts and tries to prove some obscure point with that misunderstanding. I'm not sure that this merits the level of discussion that we provide him with.
George
I can resist anything except temptation - Oscar Wilde
-
Guest
Ladies and Gentlemen,
I have had the opportunity to speak with Mr. Cherry at length about digital imaging as it applies to both standard digital imaging and video. George Reis is on target with his analysis of Mr. Cherry. According to Mr. Cherry himself, he has or is working in some capacity for defense attorneys and is associated with a group that deals with standards for business imaging. He admittedly has no experience in forensics.
I also had the opportunity to see portions of a website he intended to post prior to it actually going on the internet. There was a blatant misrepresentation of a quote from a CLPE that could be used to prove his point. Only a portion of a sentence was to be quoted in the posting, and when the quote was read in its entirety, it would mean something else entirely. Mr. Cherry also had no respect for any comments made to him.
This post is not intended to offend anyone or to in any way belittle or slander Mr. Cherry. He appears to be an educated man.
I have had the opportunity to speak with Mr. Cherry at length about digital imaging as it applies to both standard digital imaging and video. George Reis is on target with his analysis of Mr. Cherry. According to Mr. Cherry himself, he has or is working in some capacity for defense attorneys and is associated with a group that deals with standards for business imaging. He admittedly has no experience in forensics.
I also had the opportunity to see portions of a website he intended to post prior to it actually going on the internet. There was a blatant misrepresentation of a quote from a CLPE that could be used to prove his point. Only a portion of a sentence was to be quoted in the posting, and when the quote was read in its entirety, it would mean something else entirely. Mr. Cherry also had no respect for any comments made to him.
This post is not intended to offend anyone or to in any way belittle or slander Mr. Cherry. He appears to be an educated man.
-
Steve Everist
- Site Admin
- Posts: 551
- Joined: Sun Jul 03, 2005 4:27 pm
- Location: Bellevue, WA
Here is the website where Michael Cherry posted the images referenced in the beginning of this thread:
http://www.cherrymeyer.com/
As of right now, if you click on the "more images" at the bottom of the page, you can see these images.
http://www.cherrymeyer.com/
As of right now, if you click on the "more images" at the bottom of the page, you can see these images.
Steve E.
-
Michael Cherry
1. WSQ and not JPEG is used by AFIS/IAFIS to store digitized fingerprints, does it matter?
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
5. Any of us can apply very severe lossy compression to an image and cause it to become degraded
Mr. Reis
Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
Fingerprint images are evolving to 1000 ppi and WSQ is being replaced with various forms of JPEG
6. If I want my image frames to also be the same size, then I would need to crop some of the images
Mr. Reis
Eliminate(crop) evidence?
7. I don't believe he (Michael Cherry) works in our field
Mr. Reis
My beliefs are published and well known in the biometric and criminal law communities. I was referenced in Dr. Mitchell’s Book on JPEG in 1992
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
5. Any of us can apply very severe lossy compression to an image and cause it to become degraded
Mr. Reis
Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
Fingerprint images are evolving to 1000 ppi and WSQ is being replaced with various forms of JPEG
6. If I want my image frames to also be the same size, then I would need to crop some of the images
Mr. Reis
Eliminate(crop) evidence?
7. I don't believe he (Michael Cherry) works in our field
Mr. Reis
My beliefs are published and well known in the biometric and criminal law communities. I was referenced in Dr. Mitchell’s Book on JPEG in 1992
-
George Reis
- Posts: 147
- Joined: Wed Jul 27, 2005 1:00 pm
- Location: Orange County, CA - USA
- Contact:
I don't understand Mr. Cherry's response, but there are some interesting things to observe regarding the images on the his site.
Because there is virtually no documentation on that page, it is difficult to know what the images are supposed to represent, but we do know some things based on Mr. Cherry's posts here.
The first pair of images of the pocket watch are to show the effect of over compression using the WSQ algorithm. The problem with the image is that it is a photographic image not a rolled fingerprint; it is color, not grayscale; the level of compression is not stated. Each of these make it an invalid example. If one wants to make a point that AFIS should not use WSQ, then one must use images that are similar in content, bit depth, color mode and level of compression as that being challenged. Otherwise, it's kind of like showing that raw meat left on the table overnight will go bad, but that doesn't have much to do with leaving a green banana on the table overnight.
The second pair of images appears to be an example of a local equalization performed on an image. No explanation is given.
The third pair of images appear to be scans of a map, with one marked 500 DPI and the other marked 4000 DPI. Although DPI refers to printing resolutions, not scanning resolutions or sampling rates (the correct term would be PPI - Pixels per inch), we'll just analyze the images. I downloaded this image (both images are combined into one file on this page), and the resolution is actually 100 PPI. Not only this, but the image on the left as been subsampled to the equivalent of approximately 12.5 pixels per inch. Since the original file is not posted, and the two were combined to a single file, and the resolution of the posted file is substantially less that the captions indicate, one wonders whether this was meant to be deceptive. To be fair, a reference to the original maps should be made and the actual scans should be made available, not a 12.5 PPI image that is marked as being 500 DPI!
The last two pairs of images have no captions and I can't recall any discussions about them previously, so I can't comment on them, except to say that the last pair of images appear to have been taken from the Salient Stills website which they use as a sample of their software.
George
Because there is virtually no documentation on that page, it is difficult to know what the images are supposed to represent, but we do know some things based on Mr. Cherry's posts here.
The first pair of images of the pocket watch are to show the effect of over compression using the WSQ algorithm. The problem with the image is that it is a photographic image not a rolled fingerprint; it is color, not grayscale; the level of compression is not stated. Each of these make it an invalid example. If one wants to make a point that AFIS should not use WSQ, then one must use images that are similar in content, bit depth, color mode and level of compression as that being challenged. Otherwise, it's kind of like showing that raw meat left on the table overnight will go bad, but that doesn't have much to do with leaving a green banana on the table overnight.
The second pair of images appears to be an example of a local equalization performed on an image. No explanation is given.
The third pair of images appear to be scans of a map, with one marked 500 DPI and the other marked 4000 DPI. Although DPI refers to printing resolutions, not scanning resolutions or sampling rates (the correct term would be PPI - Pixels per inch), we'll just analyze the images. I downloaded this image (both images are combined into one file on this page), and the resolution is actually 100 PPI. Not only this, but the image on the left as been subsampled to the equivalent of approximately 12.5 pixels per inch. Since the original file is not posted, and the two were combined to a single file, and the resolution of the posted file is substantially less that the captions indicate, one wonders whether this was meant to be deceptive. To be fair, a reference to the original maps should be made and the actual scans should be made available, not a 12.5 PPI image that is marked as being 500 DPI!
The last two pairs of images have no captions and I can't recall any discussions about them previously, so I can't comment on them, except to say that the last pair of images appear to have been taken from the Salient Stills website which they use as a sample of their software.
George
I can resist anything except temptation - Oscar Wilde
-
Michael Cherry
1. WSQ and not JPEG is used by AFIS/IAFIS to store digitized fingerprints, does it matter?
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
5. Any of us can apply very severe lossy compression to an image and cause it to become degraded
Mr. Reis
Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
Fingerprint images are evolving to 1000 ppi and WSQ is being replaced with various forms of JPEG
6. If I want my image frames to also be the same size, then I would need to crop some of the images
Mr. Reis
Eliminate(crop) evidence?
7. I don't believe he (Michael Cherry) works in our field
Mr. Reis
My beliefs are published and well known in the biometric and criminal law communities. I was referenced in Dr. Mitchell’s Book on JPEG in 1992
8. I don't understand Mr. Cherry's response, but there are some interesting things to observe regarding the images on the his site.
Mr. Reis
Are the images on my web site the exact images Larry and I posted approximately one year ago? Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
The Forensic Digital Fingerprint Standard is moving from 500 ppi WSQ to 1000 ppi J2000 (JPEG 2000).
Dr. Mitchell’s bio is as follows:
Dr. Joan L. Mitchell graduated from Stanford University with a B.S. in physics in 1969. She received her M.S. and PhD. degrees in physics from the University of Illinois at Champaign-Urbana in 1971 and 1974, respectively. She joined the Exploratory Printing Technologies group at the IBM T. J. Watson Research Center immediately after completing her PhD. She was a manager there for nine years. She then worked for three years in IBM Marketing before returning to the IBM Research Division in 1991 to work again in the Image Technologies group as a manager. From 1987 through 1994, she was a member of the ISO and CCITT international Joint Photographic Experts Group which standardized the color image JPEG compression algorithm. She was the final editor of JPEG Part 1, and in 1992, coauthored a book about JPEG. In 1994, she took a two year leave of absence from IBM during which she coauthored a book on MPEG, consulted for IBM Burlington, and was a visiting professor at the University of Illinois for six months. She returned to the IBM T.J. Watson Research Center as a Research Staff Member in the Image Applications Department. For the last three years she was on temporary assignment with the IBM Printing Systems Division in Boulder, CO, transferring there permanently in 2002.
Since 1976, Joan has worked in the field of image processing and data compression. She received IBM Outstanding Innovation Awards for Two-Dimensional Data Compression in 1978, for Teleconferencing in 1982, for Image View Facility in 1985, for Resistive Ribbon Thermal Transfer Printing Technology in 1985, for Speed-Optimized Software Implementations of Image Compression Algorithms in 1991, and for the Q-coder in 1991. December 2001,she was awarded an Outstanding Technical Achievement Award for Algorithms for Improved Printer Performance Transferred to IBM's Printing Systems Division and her Twenty-first Invention Achievement Plateau Award. She was elected to the IBM Academy of Technology in 1997, and became an IEEE Fellow in 1999. She is a member of APS, IEEE, IS&T, and Sigma Xi and co-inventor on 40 patents. She was made an IBM Fellow in 2001. In 2002, she initiated a Master Inventor program for PSD in Boulder and became a Master Inventor there.
Approximately one year ago, Larry Meyer and I posted what appeared to be an out-of-focus image of a watch face. When JPEG images degrade from insufficient resolution, you see blocks. When WSQ images degrade from insufficient resolution, you see out-of-focus.
2. Those images you posted were a joke. You didn't even know what you were doing when you sized them
Steve E.
We posted a 35mm image and a digital camera image. Digital cameras use the video format which includes the video aspect ratio. It is not unusual for a digital camera to record video. I have never seen a digital camera that recorded 35mm.
The aspect ratio (length x width) of a 35mm image is not the same as that of a video image. The two images we represented cannot be accurately displayed (represented) as equal in size.
3. this reads as though you would not be able to size both a digital and a 35mm image to be equal? Of course you can, I do it every day
Sandra Wiese
**********EXPANDED RESPONSE***********************************************
The two images we represented cannot be accurately displayed (represented) as equal in size.Computer software cannot accurtely change the laws of physics.
4. I am at a loss to understand your post. When I saw the photographs last year they were out of focus.
Charles Parker
The 35mm representation was not out of focus. The digital camera representation was out of focus. The legnth and width of the two images were as they should be, different.
Please perform your own experiment. Take a WSQ image and reduce its resolution - instead of JPEG blocks you should see out of focus.
5. Any of us can apply very severe lossy compression to an image and cause it to become degraded
Mr. Reis
Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
Fingerprint images are evolving to 1000 ppi and WSQ is being replaced with various forms of JPEG
6. If I want my image frames to also be the same size, then I would need to crop some of the images
Mr. Reis
Eliminate(crop) evidence?
7. I don't believe he (Michael Cherry) works in our field
Mr. Reis
My beliefs are published and well known in the biometric and criminal law communities. I was referenced in Dr. Mitchell’s Book on JPEG in 1992
8. I don't understand Mr. Cherry's response, but there are some interesting things to observe regarding the images on the his site.
Mr. Reis
Are the images on my web site the exact images Larry and I posted approximately one year ago? Dr. Joan Mitchell a founder of JPEG AND MPEG observed, “500 ppi WSQ fingerprints do not look as bad as they should. When WSQ images lack sufficient resolution they appear as out-of-focus.”
The Forensic Digital Fingerprint Standard is moving from 500 ppi WSQ to 1000 ppi J2000 (JPEG 2000).
Dr. Mitchell’s bio is as follows:
Dr. Joan L. Mitchell graduated from Stanford University with a B.S. in physics in 1969. She received her M.S. and PhD. degrees in physics from the University of Illinois at Champaign-Urbana in 1971 and 1974, respectively. She joined the Exploratory Printing Technologies group at the IBM T. J. Watson Research Center immediately after completing her PhD. She was a manager there for nine years. She then worked for three years in IBM Marketing before returning to the IBM Research Division in 1991 to work again in the Image Technologies group as a manager. From 1987 through 1994, she was a member of the ISO and CCITT international Joint Photographic Experts Group which standardized the color image JPEG compression algorithm. She was the final editor of JPEG Part 1, and in 1992, coauthored a book about JPEG. In 1994, she took a two year leave of absence from IBM during which she coauthored a book on MPEG, consulted for IBM Burlington, and was a visiting professor at the University of Illinois for six months. She returned to the IBM T.J. Watson Research Center as a Research Staff Member in the Image Applications Department. For the last three years she was on temporary assignment with the IBM Printing Systems Division in Boulder, CO, transferring there permanently in 2002.
Since 1976, Joan has worked in the field of image processing and data compression. She received IBM Outstanding Innovation Awards for Two-Dimensional Data Compression in 1978, for Teleconferencing in 1982, for Image View Facility in 1985, for Resistive Ribbon Thermal Transfer Printing Technology in 1985, for Speed-Optimized Software Implementations of Image Compression Algorithms in 1991, and for the Q-coder in 1991. December 2001,she was awarded an Outstanding Technical Achievement Award for Algorithms for Improved Printer Performance Transferred to IBM's Printing Systems Division and her Twenty-first Invention Achievement Plateau Award. She was elected to the IBM Academy of Technology in 1997, and became an IEEE Fellow in 1999. She is a member of APS, IEEE, IS&T, and Sigma Xi and co-inventor on 40 patents. She was made an IBM Fellow in 2001. In 2002, she initiated a Master Inventor program for PSD in Boulder and became a Master Inventor there.