Resizing Image

[goddi]

Greetings,

I know we have gone through many discussions about resizing. But I think I have a little different question on what is the better way to do this.

I recently replaced my Nikon D80 with the Nikon D7000. The size of the image files are now much larger. I just returned from a trip with over 3,500 images and over 250 video files. So my concern now is keep the PTE slideshows within a reasonable size.

I tried 2 programs for resizing: Faststone and Photoscape. Since my monitor is 1920x1080, I am resizing based on the long side of 1920. This reduces the size of the image file, but not enough. Faststone lets you resize image based on the long side of 1920. However, I see that Photoscape allows resizing based on the long side of 1920 AND you can put in a percentage reduction, like 80%, at the same time. With Faststone, I don't see that you can use both parameters at the same time, so It looks like Photoscape really does a good job in getting a smaller file size..

My original size of my test image (from my D7000, 4928x3264) is 8923.

Faststone, using the long side of 1920, reduced the file size to 1969.

Photoscape, using the long side of 1920, reduced the file size to 1986.

Photoscape, using the long side of 1920 AND 80%, reduced the file size to 449.

I put these files into PTE and I could not see any real difference between them. I'd like to know if I am going down the right path in reducing the size of my images and still maintain the quality for the final slideshow by using Photoscape and the parameters of 1920 for the long side and 80% reduction?

Thanks.... Gary

[Lin Evans]

Hi Gary,

That works well - I'm certain you are already aware of this, but don't overwrite your originals with the reduced file size images.

Essentially, the only time you need an image larger than your intended display audience (in your case 1920x1080 pixels) is when you are contemplating a deep zoom into picture details. In such a case you may want to use the original jpg from your D7000. If you are really trying to conserve overall file size, even then you may want to crop the original and simply use the crop rather than zoom into the full image.

In terms of the file size of the executable file created by PTE, compressing jpgs will greatly affect this. In terms of resources on the system being used to play back the show, there is no difference between an uncompressed and greatly compressed jpg except perhaps image quality. As you are undoubtedly aware, jpg files are fully "uncompressed" in memory before they are displayed on a computer screen. So, for example, if we begin with a 10 meg file and use jpg compression to make it into a 3 meg file, for storage purposes inside an executable container, the compressed file will result in a smaller executable size. However, when that executable file is played by the system, it expands to its full 10 megapixel size and the system requirements to "play" this file are the same as if you had used the original.

So the only way to actually achieve a resources relief is by removing pixels. This is done by resampling and saving the resampled copy of the original. Since the vast majority of display devices today have a resolution equal to or less than HD quality (1920 x 1080) there is no real advantage in your images being any larger than two megapixel resolution. The only exception to this being for deep zooms or in the unlikely event that your audience may be looking at your show on a four megapixel display device. There are a few of these and even "some" nine megapixel display devices - but they are out of the realm of "most" of your audience for slideshows.

Whether you use Fastone, Irfanview or Photoscape is arbitrary. All will give you very "similar" results and all are equally satisfactory in my experience.

Best regards,

Lin

[fh1805]

Gary,

Further to Lin's reply...

In a typical AV sequence, the sound-track usually contributes as much or even more bytes of data than do all the still images put together. But you also mentioned video. Now that really does jack up the final file size. So, if you are wanting to produce small-ish executable files, you are going to have to pay close attention to the still images files, the sound files and the video files. The world just got more complicated!

regards,

Peter

[Bert]

Gary,

In Faststone, if you go in the jpeg settings, you can set the quality to less than 100%. I set it mostly to 80%. I see no difference in the quality between the two, but have a much smaller file size.

Regards,

Bert

[goddi]

Gary,

In Faststone, if you go in the jpeg settings, you can set the quality to less than 100%. I set it mostly to 80%. I see no difference in the quality between the two, but have a much smaller file size.

Regards,

Bert

=====================================

Bert,

Oh yea... I see it now. I just missed it.

Thanks... Gary