How to compress a photo to 20 KB and keep the face clear

The Join Pak Navy form accepts a picture only below 20 KB. PPSC allows less than 25 KB, and FPSC and ASF less than 30 KB. These are very small files. A photo from a phone camera is often a hundred times larger, so most of the picture has to be thrown away to reach the limit. Whether your face is still clear afterwards depends on what gets thrown away, and you have more control over that than you might expect.

What uses up the file size

A JPG file stores detail. The more detail there is in the picture, the larger the file. Three things add detail that you do not need:

• A busy background. A curtain, a door, a shelf or a tree behind you is full of edges and texture. Each of them takes space in the file that could have gone to your face.
• Grain. A photo taken in dim light is covered in fine speckles. To a JPG those speckles are detail, and it spends file size keeping them.
• Extra area. If you are small in the middle of a wide photo, most of the pixels show the room and not you.

A plain wall in good light is the opposite of all three. Flat colour costs almost nothing in a JPG, so nearly the whole 20 KB is left for your face, hair and shoulders.

Take a photo that compresses well

1. Stand in front of a plain white or light blue wall, about two feet away from it.
2. Face a window in daytime so that your face is evenly lit. Do not use the flash.
3. Ask someone to take the photo with the back camera, from about four to five feet away, at the height of your eyes.
4. Wear a plain shirt. Small checks and stripes are another kind of detail that costs file size.
5. Clean the camera lens first. A smudged lens gives a soft photo, and compression makes a soft photo worse.

Crop first, then compress

Crop the photo to head and shoulders before it is compressed, not after. When the crop is tight, every pixel in the small file shows part of you. The resizer on this site does both steps in the right order: you place your head and shoulders in the frame, and it then lowers the pixel size and the JPG quality only as far as the limit requires.

For a 20 KB limit the result is usually a passport shaped picture a few hundred pixels wide. That sounds small, but the picture is shown on a form at about the size of a postage stamp, and at that size it is sharp.

Mistakes that leave the photo blurry

• Compressing a file that was already compressed. Each time a JPG is saved again it loses a little more. Always start from the original photo, not from a copy that another app has already reduced.
• Taking a screenshot of the photo. A screenshot has the pixel size of your screen, not of the photo, and it is saved as a PNG that then has to be converted.
• Sharpening or adding a filter. Both add artificial edges, which cost file size and look harsh after compression.
• Photographing a printed photo. The paper’s texture and the glare on its surface become detail in the new picture.
• Stretching a small picture to make it larger. Detail that is not in the picture cannot be added back.

Check the result before you upload

Look at the downloaded file at its normal size, not zoomed in. Your eyes, nose and mouth should be clearly defined and the edge of your face should be clean. Some softness in the hair and a slightly blotchy wall are normal at 20 KB and will not be noticed on the form.

If the face itself looks blocky, the photo probably has a busy background or was taken in poor light. Changing the tool will not help. Retake the photo against a plain wall in daylight and run it through the resizer again. The difference at the same file size is usually easy to see.

The limits at a glance

• Join Pak Navy: less than 20 KB.
• PPSC: less than 25 KB, for the photograph and for the CNIC front image.
• FPSC: less than 30 KB, JPG or JPEG.
• ASF: less than 30 KB, for the photograph and for the CNIC front image.

Each of these is quoted from the organisation’s own document on its page on this site, with the date it was checked.