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-   -   Kodak Z700 fraudulent MP count (https://forums.steves-digicams.com/kodak-24/kodak-z700-fraudulent-mp-count-57114/)

rockbug63 May 31, 2005 2:34 PM

:?Just bought a Z700, have had a DC 290 since "99 and ran a small foto biz at home.
Would like to start a petition to make Kodak responsible for false advertising regarding the pixel count (4 M) of this camera. Cannot get more than 2 M !!! Nothing else in the consumer electronics industry falsifies specs this badly . Manual staes you can print 20 x 30 prints!! If you use the (divide pixel count by 200) method , its only good for a 12x9's. Just how bad are Kodak's in gerneral

DGehman May 31, 2005 2:55 PM

How are you measuring this? I just checked the sample pictures from Steve's review of the Z700, and they're 2304 x 1728 pixels... that's 3,981,312 pixels.

style="BACKGROUND-COLOR: #000000"Yes, print specs are worthless without print resolution stated. Did you email Kodak prior to purchasing to ask this? I've had trade show graphics done at 72 dpi, 20 x 30, and they work fine for a normal viewing distance (6 feet or so).

style="BACKGROUND-COLOR: #000000"My DX7630 "6.2" MP comes in at 2856 X 2142 or 6,117,552... according to both Mediachance Photo-Brush and Corel Photo-Paint... believe me, I haven't counted them by hand.

rockbug63 May 31, 2005 4:13 PM

I am pushing the camera with the most color intensive, full daylight photos I can render, then check size after download to my PC, or I also check the available pictures (camera set to 4MP res.)count of over 300 photos with a Kodak 512M card. No matter how you slice it a 4MP camera with a 512 card should only be able to take about 100 photos.

DGehman May 31, 2005 4:34 PM

Ah, I see. The size IN BYTES of the JPEG file is unrelated to the size IN PIXELS when decompressed. Kodak is well known for its aggressive JPEG compression, even on the "fine" setting. You get more pictures for a given card size at a given megapixel picture setting than with other, less compressive cameras. They must have decided to make their "film" go farther.

That said, it's the pixel size AFTER the JPEG is read into a graphics editor that is the actual size.

Corel Photo-Paint reports one of my DX7630 (6.1 MP) files as...

width: 2,856 pixels

height: 2,142 pixels [w. x h. = 6,117,552 pixels, 6.1 MP)

size in memory: 22,152,168 bytes [NOT PIXELS]

size on disk: 2,384,704 bytes [NOT PIXELS] on disk.

That's around 10:1 JPEG compression.

Dave

DGehman May 31, 2005 7:09 PM

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I'll try to make this more clear by taking an excerpt from a full photo and saving it at different JPEG compression levels. The size in pixels stays the same throughout the sequence.

The concept I'm trying to illustrate is that pixel size and file size in bytes are not directly related. The picture in each case is 743 pixels wide x 551 pixels high, for a total resolution of 409,393 -- less than 1/2 MP.

This oneis saved at 95% (very high quality,meaning alow amount of compression). The file size is 208 KB. Across the whole scene, 1 byte on picture card or diskis storing2 pixels' worth of picture.

Note that this picture size on disk WITHOUT compression is 1,215 KB saved as an older picture file type, TIFF.In this format, for this pic, it takes 3 bytes to store 1 pixel.

As the amount of compression goes up, you'll see more and more JPEG artifacts -- blocky areas where detail is being lost.



DGehman May 31, 2005 7:11 PM

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This is 75%. File size is 85 KB.

Even though this is half the size (on disk) of the first, it still looks OK. And pixel-wise, it is the same height and width.


In this file, 1 byte is storing 4.8 pixel's worth of picture.

DGehman May 31, 2005 7:12 PM

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This is 50%. File size is 60KB. Notice as we're going, the picture is the same physical size on screen.


Now 1 byte is storing 6.8 pixel's worth of picture.



DGehman May 31, 2005 7:14 PM

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This is 25%. File size is 43 KB. Losing a lot of detail on the side walls of the buildings...

1 byte is storing 9.5 pixels...

DGehman May 31, 2005 7:15 PM

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10% - 31 KB file size... obvious loss of detail in the sky, brick building, sign... everywhere.

DGehman May 31, 2005 7:17 PM

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5% (95% loss)... file size 25 KB... miserable quality, but same pixel height & width...

1 byte on the card is now storing 16 pixels, but 16 pounds of stuff in a 1-pound sack is just too much...





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