300 dpi how many pixels

We now know how many pixels are in the image. So how do we get to file size. Well this is a grayscale image and we know from the section on image pixels that for a grayscale image each pixel is 8 bits or 1 byte in file size.

So in total the A4 image of 8,, pixels has a file size of 8,, bytes or about 8. So it would be a whole lot easier if your editor asking you for an image big enough to fit the size he wants to print it at asked you for an 8 MB grayscale image. Or if he wanted it in RGB colour he would multiply that figure by three and ask you for a 24 MB image. NOTE: While it is simplest to have just one unit of measurement, such as everything measured in either inches or centimetres, it is still common in some countries to use a mix of the two.

Often paper sizes are measured in millimetres by using 'A' sizes, but image resolution is still quoted as 'Dots per Inch'. This is inconvenient as it requires measurements to be converted at times, but you will just have to be put up with this until full metrification becomes standard.

It is not necessary to calculate the file size exactly every time. Photoshop has an Image Size panel that can be used as a calculator. Make sure the 'Constrain Proportions' box is unticked to allow width and height to be separate, and that the 'Resample Image' box is ticked to allow the resolution to be separate as well. Now figures can be entered into the Document Size highlighted with the file size appearing at the top of the palette indicated.

Figure 7 The image size palette provides an accurate way of calculating the size of a digital image you have opened in Photoshop. You aren't always in front of a computer when you need to calculate image size though. So it is really helpful to have a rule of thumb that guides you.

The beauty of the number 24 is that it is so divisible, and therefore easy to calculate file sizes. Take a piece of A4 paper and write '24 on it.

Fold it in half and write 12, fold again and write 6, then fold once more and write 3. Almost all the images you use will fit one of these sizes. A grayscale is one third of an RGB so write 8,4,2,1 instead.

For a CMYK image write 32,16,8,4 as it has one extra channel. If the image is 16 bit then double the figures. In this way, wherever you are you can impress your editors or clients by a speedy calculation of what file size they need. NOTE: The figures used above are not exact, but they are easily divisable round numbers that allow you to quickly calculate the rough image file size required.

If you need to have a larger file size than was provided by the digital camera or scanner, then Photoshop can create the extra pixels. But this does come at a cost. On the right is an image that was one tenth the image size of that on the left. While there is nothing to stop you resizing an image this way, be aware that Photoshop has no reference to what the original unscanned image looked like and therefore has to 'invent' the extra pixels.

An increase of several percent will not be noticed, but the more the resizing, the softer the image will become. Figure 9 The image on the left is the original quality. The one on the right was reduced to a 10th the size and then interpolated up in Photoshop to the same size.

You can see how soft the image becomes as Photoshop simply invents pixels and blurs all edges. The best solution is to do the scan again at the correct size. But if rescanning is not possible then there are some different interpolation methods to help with the problem. Genuine Fractals is one such program that allows significant interpolation without significant loss of quality.

You may then crop the image to reduce the file size, or use interpolation to increase the file size. For the sake of simplicity, let us just deal with the finished image after you have shot it, converted it, and done any cropping. This image, when opened in Photoshop, has an "open" or "working" file size, as seen in the Image Size Panel section above. However, when you come to save the finished image you will have to decide about file compression.

Our technical team will provide you with a free PDF proof that you must approve before the project goes into production. At this time, you will be informed of any low-resolution images in your project and given the opportunity to find a solution.

If there is no solution and you are fine with the image being at risk for looking fuzzy, then we will proceed with your approved project. Latest Stories. Amanda Schauer. Menu Printing "Get Started". Getting Started with Portfolio Printi Cookbook Printing "Getting Started". Jazmin Mendez. Self-Publishing Your First Children's Self Publish. Featured Stories. Filter By Tags. Taylor Helfrich. Design Tips Print Basics resolution. Here are a few scenarios that could cause your images even if they were high-resolution originally to be low-resolution: Downloaded from a website or Google: Images found on the internet are generally a lower dpi to help speed up load time.

Emailed Photo: Sometimes when you email a photo without ensuring a lossless compression, the email will default to an optimized size. This is actually compressing the size of your image. This would translate to a 3. So if your image is larger than 3. Here are a few suggestions we have to ensure a crisp printed project: Use a nice camera: While cell phone cameras are quickly becoming higher and higher resolution, it is still safest to use a camera that is built to provide a printed end product.

An inexpensive point-and-shoot camera would work just fine, but we recommend a DSLR to produce an overall higher-quality image. This will provide you with a very high-resolution raw file that you can edit and then size down to the desired size for your project.

Know your dimensions: You want your image to be dpi at the desired dimensions in your project. So if your image is going to be an 11x17 inch spread, then your image needs to be dpi at 11x17 inches. One of the biggest misunderstandings comes from the concept of resolution. The problem is that resolution can refer to many things, two of them relate to the problem at hand. They both have to do with pixels. A digital photo is not one non-dividable thing.

The amount of these pixels and the way they are distributed are the two factors that you need to consider to understand resolution. The first kind of resolution refers to the pixel count which is the number of pixels that form your photo. In order to calculate this resolution you just use the same formula you would use for the area of any rectangle; multiply the length by the height. For example, if you have a photo that has 4, pixels on the horizontal side, and 3, on the vertical size it gives you a total of 13,, Because this number is very unpractical to use, you can just divide it by a million to convert it into megapixels.

The other kind of resolution is about how you distribute the total amount of pixels that you have, which is commonly referred as pixel density. Now, the resolution is expressed in dpi or ppi , which is the acronym for dots or pixels per inch. So, if you see 72 dpi it means that the image will have 72 pixels per inch; if you see dpi means pixels per inch, and so on.

The final size of your image depends on the resolution that you choose. If an image is x pixels it means that it will print at 15 x 10 inches if you set the resolution to dpi, but it will be While the size of your print does change, you are not resizing your photo image file , you are just reorganizing the existing pixels.

Because of the aforementioned correlation between size and resolution, a lot of people think that megapixels equal quality. And in a sense it does because the more pixels you have to spread out, the higher the pixel density will be.