Photos resize first make them small and later make them big will it make any diffrence in picture quality?

Answer 1

Assuming you are using jpeg images, the answer is yes. When you resize a JPEG image in photo editing software, you are eliminating large amounts of pixels (more pixels = more detail). When you shrink the picture, an object of say 500 pixels would go to perhaps... 200 pixels. Now when you want to resize it, there will be only 200 pixels of actual detail and the rest of the pixels would be improvised from those 200 pixels.

Answer 2

It doesn't matter if its jpeg or any other rasterized image format (Vector formats, on the other hand, do not have any native resolution and can be resized indefinitely). Raster formats are formats that include bitmaps (bmp), Portable Network Graphics (png), jpegs, gifs, tifs, and many other more obscure formats. Vector formats are seldom seen by non-graphics designers and include Illustrator's native format ai, the Scalable Vector Graphics format (svg), and many others.
When you downsize a raster image, you lose pixels (say you downsize an 800x600 image to 320x240). You have lost 800x600 - 300x200 = 480000 - 60000 = 420000 pixels of information. The program has an algorithm (ie., bicubic resample in Photoshop) that tells it which pixels contribute to contrast so that it will keep those important pixels and discard others (sometimes it will create new pixels).
If you were now to upsize the picture to its previous size without using any special algorithms, the program will simply blow each pixel up to take up 480000/60000 = 8 pixels in the final image, so you get an ugly blocky mess. Programs like Photoshop have better upsizing algorithms that smooth out the blocky mess with antialiasing and other tricks.
Thus, if you need to resize an image for the web or some document, save the resized image in a different file from the original, which should never be overwritten. If you need to resize your image for printing, change its print resolution, not its size. this is usually measured in dpi (dots per inch). Increasing the dpi will make the printer put down more true pixels per inch, giving a sharper picture without affecting the digital size of the image. For example, print a (preferably a photo from a digital camera) picture at normal screen resolution of 72dpi, then increase the resolution to around 300dpi in your software and see the difference (You will not notice any difference on the screen and no pixels will be lost or gained; it is only an instruction for the printer to print the existing pixels closer together).

Answer 3

When you resize a photo in a photo editing software, like Photoshop & such, it is gonna change the picture quality.

The ideal resolution for printing is 300. If you scanned the image and want to print an image double as the original size, then you should scan the image with a resolution of 600 so that when you double the size the resolution will shrink to 300. If you want to print an image half the original size then you'll have to scan it in 150, wo when you shrink the picture the resolution goes up.

The idea is simple. Everytime you make the image larger, the resolution gets smaller. And vice versa. When you make the image twice as big, the resolution losses half the scanned resolution. It you shrink the picture into half then the resolution becomes twice the original amount.

Answer 4

It depends on the software you're using.

There are two types of resizing a bitmap: resizing a bitmap in a Vector software, such as CorelDraw will not decrease the quality.

Let's say you have a 10x16 cm image with 300 dpi resolution.

If you re-size it in CorelDraw to 50%, you'll get a 5x8 cm image with 600 dpi resolution. The quality remains the same.

On the other hand, Re sampling the image in a software such CorelPhotopaint or Photoshop will decrease the quality, as you downsize the image and the resolution.