Question - PS Crop Tool

[danielwlt]

if I use the crop tool, configured with the same resolution as indicated in the image info, will the resulting crop be resampled? or will I just lose the pixels outside of the cropped region?

thanks as always

to add to the question, what is a proper way to resize an image to photograph sizes (ie 4x6, 5x7, 8x10 or larger), without incurring the impact of resampling?

assuming a 4MP digital image with 2272x1704 resolution @ 180ppi

thanks

[Dave]

2272/180=12.6222 inches wide
1704/180=9.4667 inches high

Getting that to 4x6 (or the other measurements) will involve some heavy cropping as well as resizing.

Very recently there was quite a lengthy discussion about increasing the size of an image and how best to avoid blurring etc' to the image, but as your image will need to be reduced I don't think you have the same problems.

[TrinityOfOne]

Ignore the 180dpi, it's lies. when you download an image from the camera, always consider it in terms of 300dpi.

Set the crop tool to the size you want, eg. 6"x4"x300dpi, the bounding box will show you how much of the image will fit the aperture.

[Scott]

It kind of depends a little.

If you are taking, say a 5x7 at 300ppi and inputing 6x8 at 300ppi in the crop options, then yes you are resampling the image because it's an enlargement. However if you input 4x6/300ppi in the crop options you aren't resampling because it's a reduction. Obviously you're going to loose a little bit of detail because the smaller size can't depict as much data as the 5x7 but they quality isn't going to degrade at all.

What you can do is use the image size dialog box (Image menu) and uncheck resample image. So a 2272x1704 @ 180ppi is roughly a 9x12 at 180ppi. You can resize it to roughly a 5x7 @ 300ppi and all the data is exactly the same. In fact if printed the 5x7/300 is going to probably look a little better than the 9x12/180 due to the higher resolution.

When you uncheck resample image in the image size dialog box you'll see how width, height and resolution are all tied together. This ensures that you never lose any data. You simply reorder it. So the image always contains the same number of pixels it's just a matter of how tightly together those pixel are.

I would suggest using image size rather than the crop options. The crop options will do whatever you tell them to, therefore at times they will do unwanted things to your image. Where are image size makes it clear what you are doing - lower resolutions with enlargements.

it's best practice to never input a resolution in the crop options. THis ensures you're simply cropping the image and never resampling it.

[QUOTE=TrinityOfOne]Ignore the 180dpi, it's lies. when you download an image from the camera, always consider it in terms of 300dpi..[/QUOTE]

Uhm... huh? why does it lie? My experience is that the resolution is correct regardless of what camera you download images from.

[TrinityOfOne]

It depends what app you are using to view the image. Some give the resolution at 180dpi, some at 300dpi.

[Scott]

ahh.. okay.. Photoshop should always be accurate though. It matches width Height and ppi when opening the image.

[TrinityOfOne]

Yes, for instance, Extensis portfolio reports images as 180dpi, load the same one into PS and it's 300dpi.

[Dave]

I'm just confused on the stated dimensions being landscape input and him wanting a portrait output ..... :confused:

[danielwlt]

assuming all images in landscape format . thanks for all the help everyone