Crops & framing

SISR never stretches your photo to fit a random shape. It chooses a window with the right proportions, then scales that window to the output size. The examples below use a common 3:2 camera image (many DSLRs and mirrorless cameras) so you can match what you see on screen to the Position menu for HD and 4K.

Starting point: a 3:2 photograph

A standard 3:2 picture is one and a half times as wide as it is tall (for example 6000 × 4000 pixels). That shape is a bit taller than a widescreen 16:9 frame. So when you pick HD or UHD, SISR keeps the full width of the photo and trims from the top, the bottom, or both until the remainder is 16:9. The Position (HD / UHD) menu chooses which vertical slice you keep.

In the diagrams, the gray box is the whole photo (scaled to 300×200 units to keep the math simple). The green outline is the 16:9 area that becomes your 1080p or 4K video. Anything outside the green box is not used.

From 3:2 to 16:9 — the Position menu (and --hd-crop / --uhd-crop on the command line)

The band’s height is the image width multiplied by 9⁄16. On a 3000 × 2000 file, that height is about 1688 px, leaving roughly 312 px of extra picture above or below — which is exactly what you slide with Keep top, Center, or Keep bottom.

3:2 image with 16:9 band at top, Keep top 16:9 band
Keep top
GUI: Position → Keep top
CLI: --hd-crop keep_top or --uhd-crop keep_top
3:2 image with 16:9 band centered 16:9 band
Center (middle)
GUI: Position → Center
CLI: --hd-crop center or --uhd-crop center
3:2 image with 16:9 band at bottom, Keep bottom 16:9 band
Keep bottom
GUI: Position → Keep bottom
CLI: --hd-crop keep_bottom or --uhd-crop keep_bottom

From a real export (not just a diagram)

The sketches above are simplified. This still is from an actual render using the UHD crop and Frame overlay — a 16:9 result at 4K resolution with a small frame counter on the image.

Exported video frame showing wide 16:9 landscape with frame number overlay
Same combination you can choose in the app: Crop → UHD, Position as needed for your photo shape, and Overlay → Frame.

Same 3:2 image → Instagram (9:16)

A 3:2 landscape shot is wider than a tall phone-style 9:16 frame. To fit, SISR keeps the full height of the photo and trims equal amounts from the left and right, leaving a vertical strip in the middle. That strip is then scaled to 1080 × 1920. The Position option is not shown for Instagram in the app — framing is always this centered strip.

3:2 → 9:16 — vertical strip (sides discarded)

3:2 frame with centered 9:16 strip 9:16

Strip width = height × (9⁄16). For H = 4000 px: 4000 × 9⁄16 = 2250 px wide; on a 6000 px-wide file, equal side crops of 1875 px each. Preset: Crop → Instagram; CLI: --instagram-crop.

Other camera shapes

4:3 photos (many phones and Micro Four Thirds cameras) are even taller relative to 16:9 than 3:2. You still use Keep top, Center, and Keep bottom for HD and 4K — only more of the top and bottom is left out than in the diagrams here.

A very wide panorama (wider than 16:9) is trimmed on the sides for HD and 4K instead of the top and bottom. Other aspect ratios use the same controls; only which edges get cropped changes.

Output resolution after cropping

Preset Final size Aspect
Instagram 1080 × 1920 9 : 16
HD 1920 × 1080 16 : 9
UHD 3840 × 2160 16 : 9

At a glance (typical 3:2 photo)

Output What happens App control
HD / UHD Full width, horizontal 16:9 band; choose vertical placement. Position: Center, Keep top, Keep bottom
Instagram Full height, narrow 9:16 strip; sides discarded, centered. Crop → Instagram only (no Position in GUI)
None + max size No aspect-ratio crop; proportional scale to fit max width/height. Max width / height

See also

How to use SISR · Batch vs one folder · Overview