Camera pictures, pictures on the computer, text in Word, computer screen, mobile screen, camera screen display size Everything's all figured out!

Camera pictures, pictures on the computer, text in Word, computer screen, mobile screen, camera screen display size Everything's all figured out!

First, the picture.
xxdpi= points Dot
X is the actual size of the picture, simple point, we only calculate the height of the picture, for example, took a picture 144x144 72dpi, then its actual height is 144÷72=2 inches
DPI is the dots per inch, after the camera has taken a picture of its DPI is determined (right-click Property Summary can be seen), such as the most common 72dpi, also said the above mentioned 144x144 72dpi pictures, 72DPI means that if you print a picture according to 72DPI, it's still 2 inches (X) high.
However, we often most of the situation is the input device dpi and output device dpi inconsistency, such as the picture of the 144x144 72dpi we print a 144dpi picture of the actual height is 144÷144=1 inch (X)

Do you understand? Camera shot out of the picture of the width of the 144x144 (points dot and the number of pixels pixel relationship for a while) and DPI (not to mention the resolution, so as not to confuse the concept), here is the 72dpi is ok (if you do not use PS, etc.), but this is the difference between the two parameters in points 144x 144 is fixed, such as the camera is 144x144=20736 (according to commonly used to say that the camera is 20,000 pixels), according to the maximum ability to shoot the picture is composed of 144x144=20736 points, you can not change, unless PS, and for the height or width of 144 points, You can put them in 2 inch (x) (when the default 72dpi printing), then 2 inches There are 144 points, or 1 inches (X) in the length of the average distribution of these 144 points (when the 144dpi printing), then 1 inches of 144 points, of course, the 2nd case print out of the picture to be half a small , but it feels clearer. Or it can be understood that the dots are determined, and how large each point is is indeterminate, and the result is an indeterminate x.

Above said is the printing out of the situation, we usually see the most or the screen to see the picture, the picture is finished on the camera screen to see, uploaded to the computer on the computer screen to see, see on the phone screen, see on other screens, and so on, now say the actual size of the picture and the size of the screen we see the relationship.


Xxdpi=yxppi (yxppi= number of pixels pixel)
Points dot= pixels pixel
We take computers for example
X mentioned above, is the actual size of the picture (can change), and y? Y is the size of the picture you see on the screen, which means that the white point takes a ruler to measure how high the picture on your computer screen is 100%. Take the usual 14-inch 16:10 widescreen LCD monitor For example, the length is 12 inches x7.5 inches, for convenience we say it is 7.5 inches high. PPI is the number of pixels per inch pixel, the formula is determined xxdpi is also the yxppi=144, we see y how to calculate it? Of course it's 144÷ppi, so how about the PPI? If you use 1280x800 resolution, then ppi=800÷7.5=107, or 1280÷12=107,y=144÷107=1.35-inch =3.4cm, take your ruler for a quantity. It should be noted that in the calculation process to use the imperial and Metric conversion, 1-inch ≈ 2.5399999896876 cm, after multiple conversion and display the actual display size of the different, may be the final calculation results and actual measurement results will differ.
In fact, we usually see pictures on the screen, such as web design, do not care about its actual display size, as long as the relative size of the picture can be, that is, the high ratio of the image to the screen, because everyone's screen situation is not the same, there are small netbooks also have a large screen, We just calculate the height of the image of the screen high proportion of the line, Yxppi=yx resolution High ÷ screen high, (YX resolution High ÷ screen high)/resolution high =y/screen height, that is, the picture pixel number of resolution height of the proportion of points = picture height of the screen high proportion of the image, the example is (144=1.35x800÷ 7.5)/800=1.35/7.5=0.18, this 144px high image accounted for a high resolution of 800px 0.18, that is to say we do not have to calculate y=1.35, only with 144÷800 on the line.

Knowing the calculation process, we can see why the same picture is different in the same size as the different resolutions at different DPI. First say this picture of 144x144 in the 14-inch display 1280x800 screen resolution of its Gaojin high of 144/800, in 15 "1280x800 condition this proportion is still 144/800, but the screen is big you see the picture is big, in 14" 960x The ratio of 600 is changed to 144/600, and the image seen is bigger than the 14-inch 1280x800, while on the QVGA screen of the photo, the picture is higher than 144/240 of the screen, and the y= of 14-inch 1280x800 1.35 compared to the big is small, which is also related to the width of your phone screen, the algorithm is the same as the computer situation.
A picture of the dots=pixels is OK, which means that no matter how much your computer displays DPI, 144x144 's picture is 14 "1280x800 in the high 144/800, while the computer DPI and display resolution are not related to the print dpi, That is, no matter how much your computer set PDI, the resolution of how much, through the computer to connect the printer to 72dpi print out the picture is 2 inches high, and the other 15 or 12-inch computer results are the same.

The above mentioned are pictures, the text is different, the picture is determined Dots=pixels, the height of 144 dots, and the text is generally determined to be the actual size, that is, the point value (1 pounds =1/72 inches), For example, Word entered the commonly used fifth number italicized word points is 10.5 points, regardless of your computer display DPI is how much, the resolution is how many, the connected printer print dpi, the printed word height is 10.5 lbs, that is, for determining PT (Point points value) of the text, Its actual size is also determined. The actual size mentioned earlier x= ptx1/72, so determined the PT also determines the X, different print dpi effect is only composed of the points of the text of the difference, the 72dpi printed out of the song fifth in the height of 10.5 pounds is composed of 10.5 pounds x1/72x72dpi=10.5 points , and the 96dpi print out of the song body fifth in the height of 10.5 pounds is composed of 10.5 pounds x1/72x96dpi=14 points (such a Chinese character can not be seen clearly, the Chinese characters need at least 16x16 lattice composition to distinguish clearly).
Let's talk about the size of the text on the screen, and we'll look at the formula.
Xxdpi=yxppi
Yxppi=yx resolution High ÷ screen height =px (pixel)
So there is ptx1/72xdpi= YX resolution High ÷ screen high =px, review the situation of the previous picture, the picture PX is determined, so the same picture at different resolutions and different size of the screen display problem is actually in the PX for the fixed value, "High resolution" and "screen height" for the change of the condition of the high px/ Resolution high PX ratio problem, and for the text, point pt is OK, so the same song body fifth 10.5pt words in different resolutions and different size of the screen display problem is actually in the PT is fixed, "Display dpi", "High resolution" and "screen height" for the variable value of the word high px/ Resolution high PX ratio problem, the change situation is similar to the picture. So we can know that the higher the display DPI will make the text larger, lower the resolution will also make the text larger, of course, you change the larger the display word will be larger.

However, in the web design we generally specify the text of the PX, that is, ptx1/72xdpi=px for the fixed value, PT according to the personal computer dpi automatic adjustment, so that the purpose is to ensure that the computer in different DPI display the same proportion of text. This is the same as in the previous picture.

Camera pictures, pictures on the computer, text in Word, computer screen, mobile screen, camera screen display size Everything's all figured out!