Open Photoshop and import the images that need to be modifie

2, in the top menu bar when selecting "Image" and then click on "Image Size".

3, in the pop-up window, you can adjust the height and width of the image. You can also adjust "Resolution" (resolution), which will affect the quality of the image.

4, click "OK" to save the modified image.

note: changing the image size may cause the image quality to drop or the size to not fit
If you are not sure whether or not you should change the image size, please consult a professional.

How to change the image size using ps

Use Photoshop to change the image size, you can follow the following steps:

Open Photoshop software Start Photoshop program and go to the main interface.

0

1 Import target image

2 Click on the menu bar "Documents"
→ “Open”, find the image file that needs to be adjusted in the pop-up window, select and click on “Open”.

enter the image size adjustment interface click the menu bar “image” → “image size”, pop up the adjustment window.

change the image size parameter in the “image size” window, you can see the current image width, height and resolution.

0 adjust the pixel size

1 : enter new directly in the “pixel size” option
The width or height of the numerical value (units for pixels), Photoshop automatically adjusts the other dimension in proportion (if the restriction ratio is not canceled).

adjust the document size: If you need to print or specify the physical size, you can change the width and height of the unit (such as centimeters, inches) in the "document size" section and adjust the resolution (typically printing recommends 300 pixels / inch, the screen displays 72 pixels / inch can be).

after confirming the modification and saving the input value, click "confirm"
Applied adjustments. The image size has been changed at this time, you can save new files through the menu bar "Documents"→"Save as" to select the format (such as JPEG, PNG).

Notice :

If you want to keep the image ratio adjustments, you need to select the "restricted ratio" option (default is usually enabled) to avoid image deformation. Reducing the image size can cause detail loss, it is recommended to replicate the graphic layer or back up the original file. Enlarge the image size can cause the image to be blurred, and you can choose the "Remove sample" option in "Image"→"Image Size"
Algorithms (such as "two cubes") optimize the effect.

PS How to change the image's pixel size

Change the image size in Photoshop needs to be selected according to the target effect method, core operations are divided into adjust image size and canvas size two categories, specific tips are as follows:

operating path: the top menu bar selects

0 "image" → "image size"ng>, enter the target size (width/height) or percentage after the pop-up dialog box.

key parameters and tricks:

re-sampling image:

when selecting:Photoshop increases the pixel by adding the value algorithm, affecting the quality.

0

1

2 shrink the image

3 : suggested shrink and select

4 “double cubic sharpening”

5
The algorithm, can retain more details.

magnify the image : the selection is easy to cause blur, recommends to cancel the selection , change the size of the canvas only to keep the original pixels.

cancel the selection : adjust the size value only, do not change the total number of pixels, suitable for the equal scale of high resolution images.

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1 adjust the resolution

2 : to print, set the appropriate resolution (such as 300ppi); screen display
The display can be set to 72ppi. But the low-resolution image forced to increase the resolution can not improve the clarity. The example scenario:

narrowed a high-definition product image for web display, selected "re-sampling" and selected "double-cylindrical sharpening", entered the target pixel (such as 800×600). When enlarging a logo image, cancel the "re-sampling", just modify the size value, avoid plug-ins causing the edge to blur.

2 , adjust the size of the painting (without changing the image element)

ong> operating path : the top menu bar select "image" → "table size", enter a new size, you can select the location of the spike (such as the middle, upper left, etc.).

functional characteristics:

extension of the plate: adding empty areas around the image (such as pure, transparent background), suitable for making social media cover, adding borders, etc.0 cutting the canvas1 : reducing the canvas
When you cut the edge of the image, pay attention to retaining the main content.

Example Scene :

When you change the width of the canvas and fill the white background when you change a canvas photo to a horizontal picture. When you make the WeChat head image, the canvas is squared and the subject is in the middle.

Third, the key note

The original quality determines the result :

0 The image with low resolution (such as 72ppi, small size) is bound to be blurred, 1 can not increase clarity by adjusting the size

Example: When a customer provides a 300×200 pixel image enlarged to 3000×2000 pixel, even with the "double three" algorithm, details are lost.

Plug-in algorithm selects :

shrink image: prioritize "double cubic sharpening" or "double three".

0

1

2 enlarge image

3 : if you need to select "re-sampling", try "keep detail 2.0" (Ph13 )
otoshop CC 2018+ version), but the effect is still limited.

Non-Destructive editing recommends:

to adjust the size after copying the graphic layer (Ctrl+J) to avoid direct modification of the original image.

to use the "smart object" scale: the right-click graphic layer selects to "convert to smart object", the subsequent scale can be restored without damage.

0 4.
With "image size".

only adjust the boundaries or leave white?

set the parameter:

select/cancel "re-sampling", select the plug-in algorithm.

enter the target size or percentage, pay attention to the constraint ratio (chain icon).

check the effect

0 :

1 magnify view details to confirm no seams or blurry.

2

3 low-resolution image magnification is unclear after it is recommended to replace the material.

4

5In> tip:

when saving select "Save as" Keep the original picture, avoid coverage. Frequently adjusting the size will lose quality, recommend a one-time setting in place.

by distinguishing the "image size" from the "coat size", reasonably select the insert algorithm, and respect the original resolution limit, can effectively complete the image size adjustment.

in PS change the image pixel size, can be based on the same proportion of width and height, use different methods, specifically as follows:

The same width and height ratio image

operation steps: click directly on the "image" in the menu bar, then click on the "image size", pop up the dialog box, enter the target pixel value in the width and height input box, click to determine.

, width and height ratio of different images

operation steps:

0

1 new file

2 : a new file, set well
Target pixel size, such as width 240, height 240.

copy image : copy the image that needs to be changed to the same interface as the newly created file. convert scale : in the editing tool, click “convert” and then click “scale”, drag the image to the target pixel size, such as W240XH240, and click to determine.