When is a pixel not a pixel?

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 2:29 pm

I have been following the various threads regarding the quality of still images when inserted into VS with particular emphasis on the "Zoom" facility.
My workflow is thus:
In my photo editor, I first crop the image to get the best composition keeping the cropped image to more than 2048px if possible. My originals start at 3648px wide. I then resize the image to 2048px (This being twice the size of the recommended size for PAL widescreen) I then set my crop tool to 2048 x 1152 px. I then "draw" the crop tool to the full width of my resized image and drag down till the crop tool stops at 1152px. This invariably means that the height of the image needs to be reduce to get the 16:9 aspect ration. I then move the crop rectangle up and down to get the best view. Save the image for importing into VS. If I then use the "zoom" facility I try not to zoom more than about 200%.
Now the bit I cannot understand. If I open my full size image and go straight to the crop tool having set it to 2048 x 1152px then draw a rectangle with the crop tool to whatever sizeI like no matter how small the the properties of the resultant cropped image always shows 2048 x 1152px whereas the actual size of the main image area cropped is really something like 205 x 112px. So if this method is adopted to produce images to import into VS then they are going to be very poor.
Quesion: How can the cropped image really be 2048 x 1152px?

Post by **Ron P.** » Mon Dec 28, 2009 4:16 pm

John,

What image editor are you using to crop your images? In PhotoImpact, the first 2 entries from the left are the distances the crop box is located from the left and top respectively.

For example I just loaded an image into PI X3, that was 3264 x 2176. I used your crop dimensions of 2048 x 1152. I positioned the crop box where I needed it, so that it would crop out the parts I do not want. Now those location boxes show that my crop box is located 530px from the left, and 350pxs from the top. Those do not account for all the area outside the crop box. That is just a grid coordinate, which would position the top-left corner of the crop box from the top-left corner of the image I'm going to crop.

The actual size that was removed by the crop would be 1216 x 1024

Post by **Ron P.** » Mon Dec 28, 2009 4:41 pm

Here's an example showing all the dimensions..

The sum of all the widths (530 + 2048+ 686) are equal to the width of my original image, 3264px. The sum of all the heights (350 + 1152 + 674) are equal to the height of my original image, 2176 px.

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 5:01 pm

Hi Ron
As in my signature I am using Adobe Elements 6 but the same applies to Photoshop CS3. In photoImpact it looks as if when you set the crop to a specific size that's the size that the rectangle appears on the screen. The difference is in Elements you can drag the rectangle to any size within the starting image and however much of the original image you fit in the rectangle the pixel size is always shaown as 2048 x 1152px or whatever you set the crop to!

Post by **Ron P.** » Mon Dec 28, 2009 5:08 pm

You can do that in PI too. I can move that crop box all over the image, and crop out those dimensions anywhere.

What I'm pointing out are the numbers

205 x 112px

. I'm guessing that those are the grid coordinates... unless rethinking your post, it may just be a typo. Did you mean 2050 x 1120?

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 5:26 pm

I'm guessing that those are the grid coordinates... unless rethinking your post, it may just be a typo. Did you mean 2050 x 1120?

No I meant 205 x 112 px as that is about the size that I cropped from the main image but in the properties the size still shows as 2048 x 1152px! I will do some screenshots after tea and you will see what I mean more clearly. I am just installing a trial version of PhotoImpact so I can see what you have done

Post by **Ron P.** » Mon Dec 28, 2009 5:44 pm

Ok, well I just installed my copy of PhotoShop Elements 5 to see what it was you're doing. I'll go back and have another look, now that I know that the small sizes are what you're cropping..

Also I moved this to a more appropriate forum..

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 5:47 pm

Have just duplicated what you did on PhotoImpact. I have to say it is much easier to use that Photoshop for this particular job. With PI if you crop to 2048 x 1152px that is what you get everytime. Am just doing the screenshots to illustrate what Elements does!

Post by **Ron P.** » Mon Dec 28, 2009 6:06 pm

I think I see what PE is doing. When you enter your crop sizes in the boxes, it will retain those, and no matter how you drag out your crop selection, the size of the crop will be what is set in those boxes.

To check this I dragged out a crop selection on my image. The crop dimensions in the boxes at the top still reflected my original dimensions of 2048 x 1152. My box didn't seem that large. However once I cropped it, I found that it did crop to those dimensions, not something smaller. I then saved this cropped image, and brought it into PI X3 to check the size of the image, which confirmed it to be 2048 x 1152. So I guess you need to clear the dimensions in those boxes to crop to some other sizes.

Yes it does appear that PI has an easier crop tool than PE...

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 7:00 pm

Ron
Just out of interest and to confirm your findings here's a screenshot of my Elements window. The tiny crop rectangle in the screenshot when confirmed and saved produces an image that is shown as 1224 x 1000px when in reality the image cannot be more than about 75px wide. I think Elements must take the small image and create extra pixels to match the 1224 size. This is what makes for a very poor quality image. My original workflow doesn't fall into this trap hence I have never had the problems that some members have recently been facing. Perhaps other photo editors follow Adobe's example. It might be an idea to ask how members who are having problems produce their images prior to importing into VS.

Thanks Ron for an intersting session!

Post by **Ron P.** » Mon Dec 28, 2009 7:08 pm

John,
Check the URL for your screenshot again. It seems that it is broken..

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 7:13 pm

Ron P. wrote:John,
Check the URL for your screenshot again. It seems that it is broken..

Sorry about that I clicked on Submit instead of Preview

Post by **Ron P.** » Mon Dec 28, 2009 7:20 pm

I just had a look at PSE 5 again, and I think you're correct. PSE is creating a document (image) the size of your crop, and must be fabricating the extra pixels. This does make for very poor images..

I would need to play around more in PSE to see how to make sure this doesn't happen.

mitchell65 · Post by **mitchell65** » Mon Dec 28, 2009 7:24 pm

Ron P. wrote:I just had a look at PSE 5 again, and I think you're correct. PSE is creating a document (image) the size of your crop, and must be fabricating the extra pixels. This does make for very poor images..

I would need to play around more in PSE to see how to make sure this doesn't happen.

I normally use Elements in the default cropping image setting of "No Restriction" that is found in the Aspect Ratio drop down box. This works normally then.