Reducing Megabytes

[wilfredo]

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Hi,

 

Is there any way to reduce megabytes without reducing pixels? I need to upload some pictures that need to be at least 1600 megapixels either vertical or horizontal, but no more than 5 megabytes. The problem is that when I reduce the megabytes using the Image Size in Photoshop CS3, then the megapixels also go down and the image becomes too small for this particular upload.

 

Any help will be appreciated.

 

Wilfredo

[robsteve]

Wilfredo:

 

you may be confusing the file's size when opened in Photoshop with the file's size on disk. It is probably the disk size which must be under 5mb. A high quality 5mb jpeg will open up as a much larger file in Photoshop.

 

If you are doing this for a wire service, use the photoshop image size with constrain proportions and resample image checked. Go to the resolution box first and change it to 240 and then pick the longest side and change it to 1600. It should be almost 10M in pixel dimensions. When you save this file as a high quality jpeg, the file size will be anywhere from half a mb to 1mb.

 

Robert

[Overgaard]

A way to do it is to save as JPG and then adjust i Quality.

 

Quality 8 can be used and should reduce the size to 0,25 - 0,5 MB

 

But don't go less than Quality 8

[wilfredo]

Thanks for the help but neither of those two options work. This feels like a catch 22

 

 

Wilfredo

[delander †]

1600 megapixels as a vertical or horizontal size. Seems an enormous image to me?

 

Jeff

[wilfredo]

1600 megapixels as a vertical or horizontal size. Seems an enormous image to me?

 

Jeff

 

That's what they want. In the end I had to crop the images to bring down the megabytes.

 

Wilfredo

[M.Grasmann]

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Excuse me,

but do you really mean 1600 megapixel, or 1600 pixel x 1600 pixel ?

[robsteve]

Thanks for the help but neither of those two options work. This feels like a catch 22

 

 

Wilfredo

 

Where are you looking to figure out your file size?

[wilfredo]

Excuse me,

but do you really mean 1600 megapixel, or 1600 pixel x 1600 pixel ?

 

Sorry, its PIXELS, my mistake.

 

Rob:

 

What I am trying to figure out is how to reduce the megabytes without affecting the pixels.

 

 

Wilfredo

[robsteve]

Sorry, its PIXELS, my mistake.

 

Rob:

 

What I am trying to figure out is how to reduce the megabytes without affecting the pixels.

 

 

Wilfredo

 

Save it as a jpeg is the only way to reduce the file size.

 

As I mentioned in my first post, I think you are confusing the file size in Photoshop with the file size on disk. They are not the same.

 

Robert

[M.Grasmann]

Hi Wilfredo,

 

if you have the picture size 1600x1600 pixel, with 300 dpi, and jpg quality 12, the file is under 2 MB.......to reduce the file size, lower the jpg quality (i don't go under 7) or, as said, change from 300dpi to 240dpi (for me this would be last choice, if the file is for a print)

[jack650]

Wilfredo,

 

On my CS2, the only way I know to keep it at 1600 pixels (not megapixels) in any one dimension and keep it below 5 megabytes is to compress the image into jpeg. I start out with a tiff file, then - image, resize, set to 1600 with all boxes checked, resample bicubic, ok , then File, save for web and choose the jpeg resolution I want.

 

Another way to do it would be: File, Scripts, Image processor, set jpeg quality to 12 (maximum value), check "resize to fit" , then fill in your pixel dimensions.

 

Hope this helps.

[wilfredo]

I saved as JPEG on 8 quality to reduce the file size but it seems that if you want certain images to have a Pixel Dimension of 5.00M or less, with either the width or the height at 1600 pixels depending on the second dimension of the image, sometimes it can't be done.

 

I solved the problem by cropping. I think the group I was sending my images to needs to address this issue, not everything can fit their formula. I had to sacrifice some of the image in cropping to fit their size.

 

Thanks for all the help.

 

Wilfredo

[mjh]

Is there any way to reduce megabytes without reducing pixels? I need to upload some pictures that need to be at least 1600 megapixels either vertical or horizontal, but no more than 5 megabytes.

Even without any compression, a 1600 x 1200 pixel image would take up only 2 MB (saved as a TIFF file, say), much less when saved as a JPEG – typically much less than 1 MB. I don’t quite understand where the problem lies.

[dorman]

Changing the DPI alone will NOT change the file size.

DPI is just a number that tells the printer how to translate pixels into inches.

File size depends only on pixel dimensions and the amount of compression applied, ie jpg quality.

[tiltyourhead]

Wilfredo,

 

I really think that you are not checking the images file size once it is saved to your hard drive. For example, I just checked a 16x20 image that I just sent out to be printed. This image is 4800 x 6000 pixels, 300 dpi, and saved as a level 10 jpeg. This large image is only 2.4 mb in size.

 

As others have said, a 1600 pixel image (on either side or both) would be less than 2 mb when saved to your disk. This should always be true and you shouldn't have to crop your images.

 

How are you checking the size of your images?

[wilfredo]

Wilfredo,

 

How are you checking the size of your images?

 

In PSCS3 I go to Image Size and check the size were it says: Pixel Dimensions.

 

Cheers,

Wilfredo

[miami91]

In PSCS3 I go to Image Size and check the size were it says: Pixel Dimensions.

 

Cheers,

Wilfredo

 

Therein lies your problem. Pixel dimensions are not the same thing as file size. Pixel dimensions do not take file type/compression into account. Instead, view the file itself in the Finder on your Mac, and you're bound to see a much smaller size. Alternatively, if you use Adobe Bridge along with Photoshop as your file browser, this will also show you the file size in the "Preview" window.

 

Jeff.